bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of estradiol on the progesterone receptor and on morphological ultrastructures in the fetal and newborn uterus and ovary of the rat
Authors: Nguyen B.-L. , Hatier R. , Jeanvoine G. , Roux M. , Grignon G. , Pasqualini J. R.
Published: December 2008

Abstract. The effect provoked by estradiol after administration to pregnant rats (1 mg per day) was studied in fetal and newborn uteri and ovary. Estrogen receptors are found in the fetuses of non-treated animals. Their number (in fmol/mg DNA, ± sd) in the fetal uterus (total sites, cytosol + nuclei) was at the age of 18 days: 63 ± 15; at 20 days 101 ± 13; and in the 24-h-old newborn; 415 ± 120. The respective values in the ovary were: 105 ± 25; 520 ± 60 and 410 ± 190. Estradiol stimulated significantly the progesterone receptor in the fetal uterus at 20 days old. The progesterone receptor (in fmol/mg DNA, ± sd) which was 97 ± 17 in the non-treated animals, increased to 790 ± 90 in the E2-primed animals. Newborns, 24-h-old, had no detectable progesterone receptor, but in the E2-treated animals the value increased to 1210 ± 120. In the fetal ovary of non-treated animals, progesterone receptor at the age of 18 days is: 90 ± 19; at 20 days 132 ± 47, and in the newborns 260 ± 67; in the E2-treated animals, the values are respectively 330 ± 49; 865 ± 78 and 1280 ± 307. In the fetal uteri of E2-treated animals, histological and ultrastructural studies showed an increase in the size of the uterine horn, the height of the epithelial cells, and stromal cell differentiation. It is suggested that, as was extensively demonstrated in the fetal compartment of the guinea-pig, the machinery for estrogen responses operates also during fetal development of the rat.
Demonstration of gonadotropin-induced plasma renin activity in human internal spermatic vein
Authors: Okuyama Akihiko , Nakamura Masahiro , Namiki Mikio , Takeyama Masami , Fujioka Hideki , Matsuda Minoru , Matsumoto Keishi , Sonoda Takao
Published: December 2008

Abstract. In order to investigate the secretion of renin from the Leydig cells of human testis, plasma renin activity (PRA) in left internal spermatic vein (ISV) and cubital vein (CV) was measured at the time of surgical repair of varicocele in 19 patients aged from 21 to 39 years. Ten of them were given a single im administration of hCG (10000 IU/m2) 4 days before the operation, whereas the remaining nine were not treated. Although mean PRA levels in CV in treated and non-treated groups were similar (1.25 ± 0.45 and 1.14 ± 0.38 nmol/l per h, respectively), mean PRA level of ISV in the treated group (3.52 ± 0.76 nmol/l per h) was significantly higher than that in the non-treated group (1.30 ± 0.32 nmol/l per h) (P < 0.01); serum testosterone levels in the same ISV were also much higher in the treated than in non-treated group (P < 0.001). These data show the following results; 1) under basal conditions, no release of renin from Leydig cells into testicular blood flow could be observed; 2) after treatment with hCG, the secretion of renin into the ISV seemed to be demonstrable. The present results suggest for the first time the secretion of hCG-induced renin from the human testis in vivo.
Conventional dose intravenous pulsatile GnRH therapy does not induce ovulation in polycystic ovarian disease
Authors: Wilson Janet M. , Traub A. I. , Sheridan B. , Thompson W. , Atkinson A. B.
Published: December 2008

Abstract. The value of pulsatile GnRH therapy for induction of ovulation in patients with polycystic ovarian disease remains unclear. Intravenous pulsatile GnRH therapy was administered to a defined group of 5 patients with polycystic ovarian disease; all were infertile, had an LH: FSH ratio of 2:1 on two or more occasions, and had multiple cysts on ovarian ultrasonography. All had failed to respond to clomiphene citrate. The 5 patients received increasing doses of GnRH (5–40 μg/pulse) continuously for up to 6 weeks. The response was evaluated by serial hormone levels and ovarian ultrasonography. During nine treatment periods no patient ovulated, and in only one did the LH:FSH ratio revert to normal. Four patients have subsequently had wedge resection of the ovaries and in each case the diagnosis of polycystic ovarian disease was confirmed. Pulsatile GnRH therapy was of no value in the management of this group of infertile patients with strictly defined polycystic ovarian disease.
Decreased serum insulin-like growth factor I response to growth hormone in hypophysectomized rats fed a low protein diet: evidence for a postreceptor defect
Authors: Maes M. , Amand Y. , Underwood L. E. , Maiter D. , Ketelslegers J.-M.
Published: December 2008

Abstract. In protein-calorie malnutrition, serum IGF-I concentrations are low despite high GH. This GH resistance might be due to a reduced number of liver GH binding sites as suggested by studies performed in fasted rats that were refed a low protein diet. To determine whether a postreceptor defect in GH action might also contribute to the GH resistance, we measured the number and the affinity constant of the liver GH binding sites and the serum IGF-I responses to injections of recombinant bGH in hypophysectomized female rats, fed a standard (15% protein) diet (N = 25) or a low (5%) protein diet (N = 25) for 8 days. There were no significant differences in the liver GH binding capacities between the 15% and the 5% protein-fed rats, whether expressed as pmol per liver (20.6 ± 3.5 vs 14.4 ± 1.3; mean ± sem; P < 0.2; N = 5, respectively), pmol per mg DNA (1.08 ± 0.16 vs 0.84 ± 0.07; P <0.4) or fmol per mg of protein (28.98 ± 5.04 vs 30.26 ± 2.00; P > 0.5). Likewise, the affinity constants of the GH binding sites of the 15% and the 5% protein-fed rats were not significantly different (0.78 ± 0.05 vs 0.78 ± 0.07 × 109 l/mol; P > 0.5). Despite these non-significant reductions in liver GH binding sites, the IGF-I responses 24 h after sc injections of increasing doses of bovine GH were blunted in the rats fed the 5% protein diet. The maximal IGF-I response in the rats with the normal protein intake was 360 ± 30 U/I, but only 130 ± 40 U/l in the 5% protein-fed animals (P < 0.001). The blunted serum IGF-I responses to GH, together with decreased maximal stimulation in the 5% protein-fed hypophysectomized rats, support the possibility that a postreceptor defect in GH action contributes to the GH resistance in protein-calorie malnutrition.
Characterization of thyroid hormone receptors in human IM-9 lymphocytes
Authors: Barlow John W. , De Nayer Philippe
Published: December 2008

Abstract. Although putatively identified more than 10 years ago, thyroid hormone receptors in human tissues remain poorly characterized. As a first step towards understanding the mechanism of thyroid hormone action in man we have characterized T3 binding sites in nuclei of the human lymphoblastoid line, IM-9 cells. In whole cell experiments at 37°C, nuclear binding of [125I]T3 was saturable (Kd 34 ± 6 pmol/l) and of finite capacity (≈ 350 sites/cell). The binding sites were extracted from a nuclear pellet by treatment with 0.4 mol/l KCl and sonication. Separation of bound from free [125I]T3 in the extracts was achieved using the calcium phosphate matrix, hydroxyapatite at a concentration of 0.3 ml of a 150 g/l slurry. Rectilinear Scatchard plots were obtained only when the hydroxyapatite was washed with a buffer containing 0.5% Triton X-100. Under these conditions T3 binding sites in the nuclear extracts were present at a concentration of 22.4 ± 8.6 fmol/mg protein and showed an affinity of (Kd, room temperature) 140 ± 10 pmol/l. The same assay system was used to determine the hierarchy of affinities for a range of natural and synthetic analogues. Calling T3 100, the order of potencies observed was: Triac, 500; 3,5-diiodo-3′-isopropylthyronine, 89; T4, 32; 35-dimethyl-3′-isopropylthyronine, 2; 3,2-T2, 0.7, rT3, 0.4; 3′5′-T2, < 0.01. These results suggest that the T3 binding sites present in human IM-9 lymphocyte nuclei and extracts thereof are thyroid hormone receptors. These cells may be a useful tool to increase our understanding of human T3 receptors. The use of hydroxyapatite to separate bound from free hormone may be adapted for use with extracts of other tissues to characterize these receptors further.
The effects of conjugated equine estrogens plus cyclical dydrogesterone on serum lipoproteins and apoproteins in postmenopausal women
Authors: Fletcher C. D. , Farish E. , Dagen M. M. , Alazzawi F. , McQueen D. , Hart D. M.
Published: December 2008

Abstract. erum lipoprotein and apoprotein concentrations were monitored for 24 weeks in 26 postmenopausal women treated with conjugated equine estrogens (0.625 mg/day) with the addition of dydrogesterone (10 mg/day) for the last 12 days of each 28 day cycle. The women had had no previous hormone replacement therapy. The estrogen plus dydrogesterone regimen caused significant (P < 0.05) increases in triacylglycerol and HDL cholesterol concentrations. Both HDL2 and HDL3 cholesterol were increased. There were no other significant changes in lipoprotein concentrations. Both apoprotein AI and apoprotein All concentrations increased significantly (P < 0.05) over the study period. The ratios of apoprotein AI to apoprotein All, apoprotein AI to HDL cholesterol and apoprotein All to HDL cholesterol did not change. At the doses employed in this study, the use of dydrogesterone as a progestogen alters the effects of conjugated equine estrogens on lipoproteins and reinforces the view that the effects of a combined HRT regimen cannot be predicted from a consideration of the effects of the individual components.
5,5'-Diphenylhydantoin decreases the entry of 3,5,3'-triiodo-L-thyronine but not L-thyroxine in cultured GH-producing cells
Authors: Zemel Leonard R. , Biezunski David R. , Shapiro Lawrence E. , Surks Martin I.
Published: December 2008

Abstract. We determined the effect of 5,5'-diphenylhydantoin (DPH) on the kinetics of T3 and T4 uptake in cultured GH-producing (GC) cells under serum-free conditions. GC cells accumulated [125I]T3 at a greater fractional rate than [125I]T4. The t½ of exit of [125I]T4 and [125I]T3 previously equilibrated in GC cells was 28 min for T4 and 66 min for T3. T3 and T4 entry rates were not influenced by up to a 10 000-fold molar excess of nonradioactive T3, T4, d-T4, rT3, 3,5-T2 and diiodotyrosine. Thus, entry of T3 and T4 in GC cells appeared nonsaturable and was not influenced by various thyroid hormone analogues. DPH, 25–200 μmol/l, decreased the rate of T3 entry in a dose-dependent manner and did not influence the T3 exit rate. At 200 μmol/l DPH, T3 entry decreased by 40%. Rates of entry and exit of T4 were unaffected by DPH. DPH may affect T3 and T4 entry differentially at the level of the plasma membrane.
Depression of ovarian function and plasma progesterone and estradiol-17β in female goats chronically infected with Trypanosoma congolense
Authors: Mutayoba B. M. , Gombe S. , Waindi E. N. , Kaaya G. P.
Published: December 2008

Abstract. Adult normocyclic female goats experimentally infected with Trypanosoma congolense developed irregular and shorter estrous cycles before complete cessation at the fourth cycle post-infection. This was followed within a month by a decline in the mean plasma progesterone and estradiol-17β levels. The peak luteal progesterone as well as pre-ovulatory estradiol-17β level declined progressively from the second to the fourth cycle post-infection. The ovaries became atretic with reduced numbers of primordial and primary follicles. The larger follicles became atretic at the tertiary stage with subsequent lack of corpora lutea formation. The rapidity of ovarian dysfunction appeared to be related to the degree of susceptibility of the individual infected goats.
125I-human epidermal growth factor specific binding to placentas and fetal membranes from various pregnancy states
Authors: Hofmann Glen E. , Rao Ch. V. , Carman Fred R. , Siddiqi Tariq A.
Published: December 2008

Abstract. Specific binding of 125I-human epidermal growth factor (hEGF) to homogenates of term human placentas and fetal membranes from normal and appropriate for gestational age (N = 20), intrauterine growth retarded (N = 9), twin (N = 11), White class A/B diabetic (N = 12), and large for gestational age (N = 13) pregnancies was measured. In all pregnancy states, placentas bound approximately four times more 125I-hEGF than did fetal membranes (P < 0.001). There was no significant difference in 125I-hEGF binding to fetal membranes from the various pregnancy states (P > 0.05). 125I-hEGF specific binding to placentas from intrauterine growth retarded or twin pregnancies was significantly greater compared with placentas from normal and appropriate for gestational age pregnancies (P < 0.05). The binding to placentas from pregnancies complicated by White class A/B diabetes or large for gestational age infants, on the other hand, was not significantly different from that to placentas from normal and appropriate for gestational age pregnancies. 125I-hEGF specific binding did not differ between placentas from intrauterine growth retarded or twin pregnancies (P > 0.05). Placental and fetal membrane 125I-hEGF binding did not vary with fetal sex, maternal race, placental weight, or gestational age between 37 to 42 weeks (P > 0.05). Placental but not fetal membrane 125I-hEGF binding increased with increasing infant weight when appropriate for gestational age and large for gestational age infants were included (P < 0.05, r = 0.38, N = 32) but not for intrauterine growth retarded, appropriate for gestational age, or large for gestational age infants alone.
Long-term castration decreases the androgen but not the estrogen nuclear pituitary receptors in the ram
Authors: Thieulant M.-L. , Pelletier J.
Published: December 2008

Abstract. The effect of castration on pituitary androgen and estrogen nuclear receptors was examined in eleven 3-year-old 'Préalpes du Sud' rams which were either intact (N = 5) or surgically castrated (N = 6) 11 months before. To avoid a receptor loss, pituitaries were frozen less than 1 min after slaughter. Specific androgen and estrogen bindings were measured upon extracts from purified nuclei. Neither the concentration of estrogen receptors (30.5 ± 3.0 vs 28.1 ±3.0 fmol/mg protein) nor the affinity constant (ka = 1.21 × 109 mol−1 in both groups) differed between intact and castrated rams. Conversely, androgen receptor concentrations differed markedly between groups and were found significantly higher in intact rams (11.3 ± 1.1 fmol/mg protein) than in castrated rams where nuclear receptors were undetectable in 5 out of 6 animals. This result keeps open the possibility that the decrease of LH sensitivity to testosterone negative feedback observed after long-term castration, could be related to the quasi absence of nuclear receptors, at least at the pituitary level.
Urinary excretion rate of C-peptide in fed and fasted obese humans
Authors: Pasquali R. , Buratti P. , Casimirri F. , Patrono D. , Capelli M. , Melchionda N. , Barbara L.
Published: December 2008

Abstract. The aim of the study was to evaluate the reliability of urinary excretion rate of C-peptide as a marker of B-cell function during fasting. Ten obese subjects of both sexes fasted for 5 days. Diurnal serum C-peptide was collected before and on the 5th day; morning serum samples (for glucose, insulin and C-peptide) and 12-h urine samples (7.00 to 19.00 h) were collected daily. Body weight decreased from 138.7 ± 15.9 to 132.9 ± 15.6 kg. Morning glucose, insulin (–40%) and C-peptide (–50%) fell significantly throughout the study. Mean diurnal C-peptide values were 2.19 ±0.69 nmol/l before and 0.60 ±0.19 nmol/l after fasting (P < 0.0001) and its secretion rate was 909.4 ± 297.9 and 244.4 ± 83.9 nmol/12 h (P < 0.005), respectively. Excretion rate of C-peptide fell progressively from basal (11.2 ± 4.2 nmol/12 h) to a nadir value of 1.3 ± 0.8 nmol/12 h (P < 0.0005); similarly, the C-peptide to creatinine clearance ratio fell from 0.062 ± 0.035 to 0.028 ± 0.015 (P < 0.05). These results indicate that fasting modifies renal metabolism of C-peptide thus creating several complications in the quantitative interpretation of urinary levels as an index of its secretion rate from the B-cell.
Comparative studies of insulin binding to receptor from adipocytes, hepatocytes, monocytes and erythrocytes from the pig
Authors: Hjøllund Elisabeth , Richelsen Bjørn , Pedersen Oluf
Published: December 2008

Abstract. We have described the receptor binding of A 14-labelled [125I]insulin to viable adipocytes, hepatocytes, monocytes and erythrocytes from the pig. For all cell types the binding was of high affinity, specific for insulin, the non-specific binding low and degradation of insulin in the medium was minimal. At 24°C, steady state insulin binding was achieved in all four cell types. At 37°C, steady state insulin binding could be measured to adipocytes and hepatocytes. Specific insulin binding levels and receptor affinity for blood and fat cells from the pig are comparable to that in human cells, whereas differences, especially according to affinity, exist between pig and rat cell insulin receptor binding. It is therefore concluded that the pig is a more suitable model for studies of insulin binding in man than rodents. Finally, no correlations between the individual binding levels to the different cell types were observed. Hence, measurement of insulin binding to the easier available blood cells cannot replace studies of insulin binding to target cells of insulin.
Dynamics of oxytocin, estrogen and progestin receptors in the bovine endometrium during the estrous cycle
Authors: Meyer H. H. D. , Mittermeier Th. , Schams D.
Published: December 2008

Abstract. The levels of oxytocin receptor (OTR), cytosolic progestin receptor (cPR), cytosolic and nuclear estrogen receptor (cER, nER) were measured in the endometrium of 28 heifers that had been slaughtered on a defined day of the estrous cycle, In an additional, trial endometrial tissue obtained from 78 heifers or cows at the abattoir was analyed for OTR. OTR was absent during the luteal phase (after day 6), but a minor elevation was observed after day 15. OTR increased rapidly after luteolysis on days 17–18 reaching a maximum during estrous on day 21, and decreased again during days 1–6. cER and cPR were different to OTR but followed a similar pattern with maximal levels during days 1–8 of the estrous cycle. At day 12 both receptors were minimal and increased again towards day 21. nER was maximal at day 19–21 coinciding with maximal estradiol levels and estrous. Our data indicate that owing to an increasing sensitivity of the endometrium to progesterone and estradiol after day 12, these steroids may be mainly responsible for the initiation of first PGF2α surges and luteolysis. Oxytocin seems to be of minor importance at this stage owing to low sensitivity of the endometrium for oxytocin.
Insulin-like growth factor I levels in proportionate dogs, chondrodystrophic dogs and in giant dogs
Authors: Eigenmann J. Eugen , Amador Adel , Patterson Donald F.
Published: December 2008

Abstract. Plasma insulin-like growth factor I concentrations from proportionate, chondrodystrophic and giant breeds were evaluated and compared with body size. IGF-I plasma concentrations were 91.2 ± 10.9 μg/l in Keeshounds (proportionate dog), 122.6 ± 25.4 μg/l in Bassethounds (chondrodystrophic dog) and 280 ± 22.8 μg/l in German Shepherds (proportionate dog). The highest IGF-I level (389.6 ± 24.2 μg/l) was found in the New Foundland, a giant breed (mean ± sem). The mean body weight was 11.8 ±0.4 kg in Keeshounds, 15.4 ± 1.4 kg in Bassethounds, 32 ± 1.5 kg in German Shepherds, and 45.6 ± 1.7 kg in New Foundlands (mean ± sem). Body weight and plasma IGF-I concentration were significantly correlated (y (IGF-I) = −7.43 + 8.7 × (body weight); P < 0.0001.
Chronic GnRH administration in prepubertal male pigs
Authors: Dijkstra Grietje , van Vlissingen J. Martje Fentener , Wensing C. J. G. , van Dorst-Bruijns P. M. M. , Degenhart H.J. , Erkens J. H. F. , van de Wiel D. F. M.
Published: December 2008

Abstract. The effect of chronic pulsatile low-dose GnRH treatment on the juvenile testis and associated structures was evaluated in relation to hormonal parameters in the peripheral blood in the pig. Starting at 8 weeks of age, male pigs (crossbreds of Dutch Landrace and Yorkshire breeds) were injected 6 times daily im with 0, 75 or 250 ng GnRH/kg body weight during 4 weeks. Immediately after the treatment period, a GnRH stimulation test with 750 ng GnRH/kg iv was carried out. Samples for plasma LH, FSH, testosterone and 5αDHT measurement were obtained weekly (basal level) and after GnRH stimulation. The pigs were castrated at 12 weeks of age and the weights and lengths of the testis, epididymis and cremaster muscle were recorded. Intratesticular testosterone and 5αDHT concentrations were determined, and the testis and epididymis were evaluated for histological changes. Basal plasma hormone concentrations, intratesticular androgen concentrations and the response of the pituitary gland to stimulation had not been affected by GnRH treatment. Pigs receiving the higher treatment dose of GnRH showed less increase in testosterone levels in response to the stimulation dose at 12 weeks of age than the other pigs. Morphologically, no changes were observed in the epididymis and cremaster muscle after GnRH treatment and no signs of reactivation of structures that can provoke testicular descent could be seen. The development of the seminiferous epithelium was more advanced in the GnRH-treated groups, apparently in a dose-dependent manner.
Peripheral and hepatic resistance to insulin and hepatic resistance to glucagon in uraemic subjects
Authors: Schmitz Ole
Published: December 2008

Abstract. To characterize endogenous glucose production in uraemia, nondialyzed uraemic patients and controls were exposed to two major modulating hormones, insulin and glucagon. Nineteen uraemic and 15 healthy subjects underwent either a 2-step (insulin infusion rates: 0.45 and 1.0 mU·kg−1·min−1) or a 3-step (insulin infusion rates: 0.1, 0.2 and 0.3 mU·kg−1·min−1 sequential euglycaemic insulin clamp. Average steady state serum insulin concentrations were almost identical during all five infusion rates in uraemic patients (16,22, 26, 31 and 66 mU/l) and controls (15, 19, 24, 33 and 68 mU/l). At all steps, insulin infusion was accompanied by significantly lower glucose disposal rates ([3−3H]glucose) in uraemic patients compared with controls (P < 0.05 or less). Moreover, the restraining potency of insulin on endogenous glucose production was much more prominent in healthy than in uraemic subjects at the lowest three infusion rates (0.6 ± 1.0 versus 1.4 ± 0.3 (mean ± 1 sd), −0.3 ± 0.7 versus 0.7 ± 0.3, and −1.1 ± 0.7 versus 0.2 ± 0.6 mg·kg−1·min−1; P < 0.05, P < 0.01 and P < 0.01, respectively), implying a shift to the right of the dose-response curve in uraemia. In contrast, basal values were comparable (2.4 ± 0.3 versus 2.2 ± 0.6 mg·kg−1·min−1) as the difference vanished at higher infusion rates, i.e. peripheral insulinaemia above ≈30 mU/l. Another 7 uraemic patients and 7 controls were infused with glucagon at constant rates of 4 or 6 ng·kg−1·min−1, respectively, for 210 min concomitant with somatostatin (125 μg/h) and tritiated glucose. The ability of glucagon to elevate plasma glucose was markedly attenuated in uraemic patients compared with controls during the initial 60 min of glucagon exposure. This difference was entirely due to diminished hepatic glucose production (3.5 ± 0.8 versus 4.8 ± 1.0 mg·kg−1·min−1; P < 0.05). In conclusion, in addition to insulin resistance in peripheral tissues, uraemia is also associated with hepatic insulin resistance. Furthermore, glucagon challenge implies impaired early endogenous glucose release in uraemia suggesting a superimposed hepatic resistance to glucagon.
Peroxidase activity and thyroglobulin iodination activity of thyroid peroxidase in non-functioning thyroid tumours
Authors: Yoshimura Hirokatsu , Ito Kunihiko , Tarutani Osamu , Hosoya Toichiro
Published: December 2008

Abstract. Both lesion (L) and adjacent normal (N) thyroid tissue from 48 patients with non-functioning adenomas and adenomatous goitres were assayed for peroxidase activity by the 'mini' assay method employing guaiacol or iodide as the second substrate. A considerable proportion of thyroids (46% of adenomas and 22% of adenomatous goitres) demonstrated no iodide oxidation activity in L although they had guaiacol oxidation activity, and these were grouped as subgroups A. The rest of these non-functioning tumours, termed subgroups B, had both guaiacol and iodide oxidation activity which was higher (3.0–4.6 times in guaiacol assay and 7.3–14.1 times in iodide assay) in L than in N. These data indicate that the non-functioning in subgroups A may be due to a lack of iodide oxidation activity and that some other defects such as an iodide transport defect may be involved in subgroups B. Furthermore, a precise and rapid assay method for thyroglobulin iodination activity of thyroid peroxidase was developed, with modifications of previous methods. On the basis of this method, we found that there is a good correlation (r = 0.94) between iodide oxidation assay and thyroglobulin iodination assay, leading to the conclusion that thyroglobulin iodination assay can be replaced by iodide oxidation assay.
The return to ovulation following early abortion: a comparison between vacuum aspiration and prostaglandin
Authors: Cameron I. T. , Baird D. T.
Published: December 2008

Abstract. The return to ovulation following early abortion (≤ 56 days amenorrhea) has been assessed after both vacuum aspiration under general anesthesia (N = 14) and menstrual induction with 16,16 dimethyltrans-Δ2PGE1 methyl ester in pessary form (N = 18). The urinary excretion of hCG, total estrogen and pregnanediol was similar in each group. There was an initial rapid decline in hCG excretion (t½ 48 h), reaching 10% of the pre-treatment value after 6 days. Twenty-nine (91%) women showed a luteal phase rise in pregnanediol excretion, with ovulation occurring on day 29 (16–37) and 24 (16–32) in the vacuum aspiration and prostaglandin groups, respectively (median (range) NS). The wide range in the return of ovarian activity was related to the variation in decline of progesterone secretion (as reflected by excretion of pregnanediol) by the corpus luteum. Asynchrony between the ovarian and menstrual cycles resulting from a delay to ovulation presents a major constraint to the use of early pregnancy interruption as a routine method of fertility control.
Somatostatin reduces posthypoglycemic insulin resistance in insulin-dependent diabetes mellitus
Authors: Kollind M. , Adamson U. , Lins P. E.
Published: December 2008

Abstract. In order to study whether somatostatin reduces posthypoglycemic insulin resistance, hypoglycemia was induced between 7.00 and 8.00 h by an iv infusion of insulin with and without somatostatin (250 μg/h) in 6 male patients with insulin-dependent diabetes mellitus (IDDM). Exogenous glucagon was infused to substitute for the suppression of its endogenous release (1.0-1.5 ng·kg−1·min−1). Insulin resistance was assessed by a somatostatin-insulin-infusion test (SIGIT) between 11.00 and 15.00 h. In the study without hypoglycemia, blood glucose was kept close to 6 mmol/l from 8.00 h until start of the SIGIT. In both hypoglycemic studies similar nadir blood glucose levels were achieved and hypoglycemia evoked the same increase of plasma epinephrine and cortisol, whereas plasma glucagon remained at its basal level. The growth hormone response to hypoglycemia was suppressed by somatostatin. At the onset of the SIGIT, the plasma levels of the counterregulatory hormones had returned to basal, and blood glucose and plasma free insulin concentrations were almost identical. During the SIGIT there were no differences in plasma free insulin or counterregulatory hormone levels. Insulin resistance, as seen following hypoglycemia, was not demonstrable in the study with somatostatin. It is concluded that somatostatin reduces insulin resistance following hypoglycemia in patients with IDDM. It is therefore suggested that an analogue with a specific GH release inhibiting property may be useful in reducing glycemic instability when given as adjunct therapy to insulin in patients with labile glycemic control.
Estrous cycle lengthening by pentobarbital in the rat: prolactin involvement
Authors: Geiger J. M. , Boehm N. , Aron Cl.
Published: December 2008

Abstract. Pentobarbital lengthens the estrous cycle when injected on diestrus 1 afternoon in the 4-day cyclic female rat. The present study was undertaken to elucidate the mechanisms involved. Bromocriptine (2.5 mg/kg sc) given 30 min before pentobarbital (30 mg/kg ip) prevented the effects of pentobarbital on both cycle lengthening and progesterone levels in diestrus 2. Serum prolactin concentrations rose 10 min after pentobarbital injection, peaked at 30 min, and returned to control values after 60 min. Our results suggest that pentobarbital-induced cycle lengthening is due to a high progesterone production on diestrus 2 morning related to the luteotropic action of prolactin.
Serum levels of estrogens and of five 'steroid sensitive' proteins in early normal pregnancy
Authors: Sparre Lottie Skjöldebrand , Brundin Jan , Carlström Anders , von Schoultz Bo , Carlström Kjell
Published: December 2008

Abstract. Serum concentrations of sex hormone binding globulin (SHBG), pregnancy associated α2-glycoprotein (α2-PAG), caeruloplasmin (Cp), α1-antitrypsin (α1-At) and transferrin (Tf), unconjugated and total estrone, and unconjugated estradiol-17β were measured twice at a 4–5 week interval in 43 cases of early normal pregnancy (gestational weeks 6–19). Significant correlations between estrogen and protein levels in the total material were observed for all proteins except for Tf. However, within 2-week intervals of pregnancy, significant correlations were obtained only in certain intervals between estrogens on one hand and SHBG, Cp and α1-At on the other. Significant correlations between rates of increase of estrogens and of proteins were obtained only at certain occasions for SHBG, Cp, Tf and α1-At. The results indicate that, although estrogens may have a modulatory function in 'steroidsensitive' protein synthesis, they are probably not the main physiological regulator.
Immunocytochemical changes in hypothalamic and pituitary hormones after acute and prolonged stressful stimuli in the anestrous ewe
Authors: Polkowska Jolanta , Przekop Franciszek
Published: December 2008

Abstract. We studied the effect of short (acute (20 min/h, for 4 h) and intermittent, long-term (20 min/h for 9 h on 3 consecutive days) electric foot shocks on the immunocytochemical localization of CRH and SRIH in the hypothalamus and of ACTH, beta-endorphin, GH and PRL in the pituitary of the anestrous ewe. Acute stress greatly reduced immunoreactive (ir) CRH in the median eminence and cellular ir ACTH, beta-endorphin and PRL, as well as the proportion of these cell types in the pituitary. A slight reduction of irSRIH in the median eminence was also observed. After long-term stress, reduction of irCRH in the median eminence was still observed. However, ACTH/beta-endorphin cells in the pituitary gland displayed increased secretory activity, manifested by hypertrophy and hyperplasia. A marked depletion of irSRIH in the nerve terminals of the median eminence was observed. The proportion of PRL cells but not their ir content returned to control levels. No effects were observed on the features of the GH cells. This study indicates that there are differences in the effect of short- and long-term stressful stimuli on the activity of hormonal systems in the anestrous ewe. Short-term stress immediately activates the CRH/ACTH/beta-endorphin axis. prolonged stress appears to augment the activation of the SRIH hypothalamic system and probably has a restraining effect on ACTH/beta-endorphin release.
Urinary metabolites of thromboxane and prostacyclin in diabetes mellitus
Authors: Gréen K. , Vesterqvist O. , Grill V.
Published: December 2008

Abstract. The in vivo synthesis of thromboxane A2 and prostacyclin was estimated in 23 diabetics through measurements of the major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-PGF1α utilizing gas chromatography-mass spectrometry. Mean excretion was similar to that in non-diabetic subjects. The possible influence of hyperglycemia on the excretion of 2,3-dinor-thromboxane B2 and 2,3-dinor-6-keto-PGF1α was evaluated in three ways: by measuring excretion before and during an acute 9-h normalization of hyperglycemia through an artificial pancreas (Biostator) as well as by comparing excretion before and 7–12 days or 40–180 days after the initiation of insulin treatment. Despite significant reducing effects on hyperglycemia or on levels of hemoglobin A1c, no effects on the excretion of the thromboxane and prostacyclin metabolites could be found. Abnormal formation of thromboxane or prostacyclin is not a generalized feature of the diabetic state.
Cloning and pretranslational hormonal regulation of testosterone 16α-hydroxylase (P-45016α) in male rat liver
Authors: Ström Anders , Mode Agneta , Zaphiropoulos Peter , Nilsson Anne-Gerd , Morgan Edward , Gustafsson Jan-Åke
Published: December 2008

Abstract. cDNA clones for P-45016α were isolated from a male liver λgt 11 expression library using antibodies against P-45016α. The clones encompassed 1633 and 1791 bp, respectively. The latter clone contained the whole coding sequence. The 20 deduced NH2-terminal amino acids were identical to those of P-450h and the cDNA sequence was in complete agreement with that of P-450 (M-1). Northern blots showed that P-45016α in the rat liver is pretranslationally regulated by the growth hormone secretory pattern. Southern blots indicated that few genes belong to the same P-450 gene family as P-45016α.
Response of circulating adrenocorticotropin, beta-endorphin, beta-lipotropin and cortisol to athletic competition
Authors: Petraglia F. , Barletta C. , Facchinetti F. , Spinazzola F. , Monzani A. , Scavo D. , Genazzani A. R.
Published: December 2008

Abstract. Acute physical exercise stimulates the activity of the hypothalamus-pituitary-adrenal axis in man. In the present study we measured plasma adrenocorticotropin, beta-endorphin, beta-lipotropin and cortisol levels in 27 male trained athletes in basal conditions, 60 min before and immediately after an official competition. The endocrine responses were evaluated in different groups of athletes participating in races (100 m, 1500 m, 10 000 m) or in the disc throw. The athletes competing for the runs showed a statistically significant increase in plasma adrenocorticotropin, beta-endorphin, beta-lipotropin and cortisol levels after the race (P <0.01), whereas the disc throwers showed no significant change in the hypothalamus-pituitary-adrenal axis hormones after the competition. The percent increase in plasma adrenocorticotropin, beta-endorphin, beta-lipotropin and cortisol was higher in the athletes who run 1500 m and 10 000 m than in those participating in the short distance race (100 m). The present results showed that plasma proopiomelanocortin-related peptides and cortisol levels increase in trained athletes following running competition and that this increase is related to the duration of the physical exercise.
Glucagon and glucose tolerance in liver cirrhosis
Authors: Greco A. V. , Altomonte L. , Ghirlanda G. , D'Anna L. M. , Manna R. , Caputo S. , Uccioli L.
Published: December 2008

Abstract. The present study was undertaken in order to establish the significance of glucagon in glucose intolerance in liver cirrhosis. The plasma glucose response to an oral glucose load (75 g) was determined in 10 control subjects and in 10 cirrhotic patients, after infusions of: glucagon (3 ng·kg−1·min−1) or saline (154 mmol/l); somatostatin (SRIH) (500 μg/h); and SRIH plus glucagon (3 ng·kg−1·min−1). Glucagon infusion did not impair glucose tolerance, neither in normal subjects nor in patients with cirrhosis. On the other hand, in both groups glucose tolerance was impaired by SRIH infusion, presumably owing to an absolute insulin deficiency. Both in normal subjects and in cirrhotic patients, SRIH plus glucagon infusion further impaired glucose tolerance, presumably as a result of excess glucagon and concomitant insulin deficiency. In conclusion, our data show that hyperglucagonemia is not an important factor in the development of the glucose intolerance in patients with hepatic cirrhosis.
Neurohypophysial hormone influence on renal function in the New Zealand genetically hypertensive rat
Authors: Ashton N. , Balment R. J.
Published: December 2008

Abstract. The acute effects of physiological levels of AVP and oxytocin administration on renal water and sodium handling have been investigated in New Zealand genetically hypertensive and normotensive rats. AVP infusion was associated with an antidiuresis in both normotensive and hypertensive rats and while normotensive rats also displayed a dose-related natriuresis, this was attenuated in hypertensive rats. Oxytocin administration had no effect on urine flow or sodium excretion in normotensive rats, but was associated with an antidiuresis in hypertensive rats. Combined hormone infusion produced a greater reduction in urine flow than following AVP alone in both normotensive and hypertensive groups and was associated with a potentiation of the natriuretic action of AVP in the hypertensive animals. The data suggest that the contribution of oxytocin to renal sodium excretion in hypertensive rats may be suppressed. A compensatory increase in basal AVP secretion in hypertensive rats may overcome their apparent renal insensitivity to AVP, to maintain appropriate sodium excretion. This intriguing disturbance in neurohypophysial function may reflect or possibly contribute to the hypertension of these animals.
Hypovolemic stimuli and vasopressin secretion in man
Authors: Hammer Mogens , Olgaard Klaus , Schapira Allan , Sørensen Mogens Bredgaard , Jensen Kai , Bonde-Petersen Flemming
Published: December 2008

Abstract. Different non-hypotensive hypovolemic stimuli were applied to 21 healthy and 20 uremic dialysis patients. The purpose was to study the effect on plasma arginine-vasopressin concentration, using orthostasis as a reference model. Orthostasis increased the plasma AVP level in healthy subjects as well as in uremic dialysis patients. In healthy subjects plasma AVP increased both when they were normohydrated and after they had been water-depleted. Lower body negative pressure (LBNP, −40 mmHg) was applied to 11 healthy males to induce a central blood volume decrease, equal to that induced by orthostasis. The plasma AVP increased in two subjects only who became hypotensive during the investigations. Ten hemodialysis patients were volume-depleted by isolated ultrafiltration. A flow directed Swan-Ganz catheter was used to measure the central intravascular pressures. Pulmonary capillary wedge pressure was reduced to normal or subnormal values during 1–2 h of ultrafiltration, without any significant changes in plasma AVP. Plasma AVP increased only in 2 patients, who became hypotensive during the investigations. Thus, of the present nonhypotensive volume stimuli only orthostasis was able to stimulate AVP secretion. Equal or even greater reductions in central blood volumes by other stimuli had no effect on AVP secretion. The results demonstrate that isolated stimulation of low-pressure volume receptors has no effect on the secretion of AVP in humans.
The immunocytochemical heterogeneity of silent pituitary adenomas
Authors: Heshmati H. M. , Turpin G. , Kujas M. , Lam X. , Van Effenterre R. , Racadot J. , de Gennes J. L.
Published: December 2008

Abstract. An immunocytochemical study was performed by the indirect peroxidase method on the pituitary tumour of 37 patients with clinical and biological signs of silent adenoma. Antisera were used against human PRL, human GH, ACTH1-24, human ACTH17-39, α-melanocyte stimulating hormone (α-MSH), human β-endorphin, α-subunit of hCG (hCG-α), and β-subunits of human LH(LH-β), human FSH (FSH-β) and human TSH (TSH-β). Immunostaining in at least 5% of the tumour cell population, with one or more antisera, was present in 13 cases; hCG-α immunostaining was the one most frequently observed. Combined immunostaining was found in 7 cases. Exclusive immunostaining was present in 6 cases: 4 with hCG-α, 1 with ACTH1-24 and 1 with TSH-β It is concluded that a significant number of silent pituitary adenomas show a certain secretory pattern of pituitary hormones or subunits of glycoprotein hormones as revealed by the immunocytochemistry.
Studies of structure-function relationship of human parathyroid hormone using rat and human renal cortical cells in culture
Authors: Takano Tsunenori , Takatsuki Kensuke , Yoneda Masahiro , Tomita Akio , Ogawa Katsuhito , Matsui Nobuo
Published: December 2008

Abstract. The structure-function relationship of human PTH was studied by testing the effects of its synthetic analogues on cAMP production in cultures of rat and human renal cortical cells. The human cell system was by two orders more sensitive to an agonist, hPTH 1-34, than the rat cell system. In both culture systems, Tyr34hPTH3-34NH2, which by itself had no influence on adenylate cyclase, caused approximately 90% inhibition of the hPTH 1-34-induced cAMP production at a molar ratio of 1000:1. On the other hand, Tyr34hPTH5-34NH2, Tyr34hPTH7-34NH2, Tyr34hPTH8-34NH2 and Tyr34hPTH9-34NH2 had weak but distinct agonist activity. When these four analogues were tested in the presence of hPTH 1-34, they acted as antagonists in the human cell system, whereas they still showed agonist activity in the rat cell system which was additive to that of hPTH 1-34. These data indicate that the amino acids at positions 1 and 2 of hPTH are important for its biological activity and that those in the sequence 9-34 also participate in the activation of adenylate cyclase. The higher sensitivity to hPTH 1-34 and the different response to some of the analogues of human renal cortical cells compared with rat renal cortical cells emphasize the importance of employing human cell systems in evaluating the structure-function relationship of hPTH.
Influence of growth factors on an insulin-producing cell line (RINm5F)
Authors: Dereli S. , Fleck H. , Sieradzki J. , Schatz H.
Published: December 2008

Abstract. The influence of IGF-I, insulin and epidermal growth factor (EGF) as well as glucose as control was studied on both growth and function of RINm5F cells, an insulin-producing cell line derived from rat insulinoma tissue. [3H]thymidine incorporation and DNA content (fluorometrically) were measured for estimating cell growth, insulin release and biosynthesis ([3H]leucine incorporation) as parameters for cell function. There was a significant increase in both [3H] thymidine incorporation and DNA content into RINm5F cells by glucose already at very low concentrations. IGF-I and high concentrations of insulin too were able to stimulate cell growth (insulin also in additional experiments with isolated rat islets). EGF, however, was without growth effect on this cell line (in contrast to previous own results in isolated islets). Insulin secretion and biosynthesis were also increased by very low glucose concentrations. IGF-I and EGF were ineffective regarding these functional parameters in RINm5F cells. Besides for glucose, our results demonstrate a role for IGF-I and insulin, but not for EGF, in regulating growth of these cells.
Further evidence that preoptic anterior hypothalamic GABAergic neurons are part of the GnRH pulse and surge generator
Authors: Jarry Hubertus , Perschl Astrid , Wuttke Wolfgang
Published: December 2008

Abstract. The in vivo release rates of GABA from the preoptic/anterior hypothalamic area (PO/AH) of ovariectomized rats were assessed by means of a focal perfusion cannula system. Seven days after surgery all animals received a sc silastic capsule implant containing either estradiol-17β (E2) or corn oil, and they were perfused 3 days later. Perfusate fractions were sampled at 5-min intervals and blood was collected every 10 min over a period of 5 h. In ovariectomized animals PO/AH GABA release was pulsatile without any diurnal rhythm. Prior to frequence analysis by means of the pulsar-programme, LH and GABA values were z-transformed. Significant LH peaks of all examined ovariectomized rats were superimposed and GABA data were arranged accordingly. It became evident that LH episodes are preceded by a significant reduction of preoptic anterior hypothalamic GABA release. The secretion patterns of GABA and LH were profoundly affected by E2 replacement. During early noon when LH levels were low, constantly elevated hypothalamic GABA release rates were observed in E2-substituted rats in comparison to ovariectomized rats. GABA release rates fell significantly during the E2-induced LH surge. Our previous demonstration of the existence of a large number of estrogen-respective GABAergic neurons in the PO/AH is suggestive of these neurons changing their activity in response to estrogen treatment. We conclude that these estrogen-respective GABAergic neurons are involved in the generation of GnRH pulses as well as in the generation of the so-called positive feedback effect of E2 on LH release. Whether the same GABAergic neurons have those effects or whether two populations of GABAergic neurons exist, one responsive for generation of pulsatile LH release, the other responsive for the estrogen-induced LH surge, remains to be elucidated.
Response of luteinizing hormone secreting pituitary adenoma to a long-acting somatostatin analogue
Authors: Vos P. , Croughs R.J. M. , Thijssen J. H. H. , van 't Verlaat J. W. , van Ginkel L. A.
Published: December 2008

Abstract. A large pituitary tumour was discovered in a 20 year old man who came to medical attention bacause of grand-mal seizures. The tumour produced biologically active LH as demonstrated by supranormal plasma LH and plasma testosterone values. Free alpha-subunit values were also elevated. In contrast, plasma FSH was in the lower normal range. Transsphenoidal operation failed to remove all tumour tissue. Detailed studies were carried out in the postoperative period. TRH and GnRH administration were associated with a rise of plasma LH and alpha-subunit, whereas plasma FSH was low and unresponsive. Bromocriptine treatment was ineffective. In contrast, both during and after treatment with SMS 201-995 for 6 weeks, a decrease of basal plasma LH values was observed. Furthermore, the administration of a single dose of SMS 201-995 reproducibly induced a decrease of plasma LH lasting for a period of about 6 h. The study suggests that SMS 201-995 may be useful in the treatment of patients with gonadotrope cell adenomas.
Development of folliculo-stellate cells in the human pituitary
Authors: Coates P. J. , Doniach I.
Published: December 2008

Abstract. The development of the folliculo-stellate cell in human fetal pituitaries has been investigated by immunocytochemical methods for S-100 protein and glial fibrillary acid protein. S-100 positivity was first observed in pars intermedia cells in a 13-week fetus. Staining with this antiserum is seen in cells of the pars distalis after 15 weeks. Glial fibrillary acid protein was not apparent until 18 weeks, when only cells in the pars intermedia were stained. These cells were not seen in the pars distalis before 28 weeks' gestation, but were present in a 39-week specimen and in a 5 day old baby. In most pituitaries examined, cells staining for S-100 and glial fibrillary acid protein were more concentrated in the pars intermedia than the pars distalis. These results suggest that folliculo-stellate cells in the human pituitary originate in the neurally associated facet of the pars intermedia and pass through this lobe to reach the pars distalis. Since these cells stain for glial related antigens, they may be a modified form of glial cell and arise in the neuroectoderm. Evidence for this hypothesis is given by a lack of both S-100 and glial fibrillary acid protein in the pituitaries of three anencephalic pituitaries. Differences in the timing of S-100 and glial fibrillary acid protein immunoreactivity may be related to either developmental aspects of the folliculo-stellate cell, or to the presence of two distinct cell types.