bluuebunny/crossref_metadata_2025 huggingface dataset:
EFFECT OF PENTOBARBITAL ANAESTHESIA ON LUTEINIZING HORMONE LEVELS IN INTACT AND OVARIECTOMIZED EWES
Authors: Ellicott Allen R. , Benoit Henry J. , Borth Rudi , Strickler Ronald C. , Woolever C. Allan
Published: December 2008

In six intact ewes, deep anaesthesia lasting 1—2 h was induced with pentobarbital given intravenously at the onset of oestrus. In a second group of six ovariectomized ewes, light pentobarbital anaesthesia was induced following a control period of 4 h and then maintained for 2, 3, or 4 h. No drug was given to control animals (seven in the first group, three in the second). Serum levels of luteinizing hormone (LH) were determined by radioimmunoassay hourly in the first group, and at intervals of 5 or 10 min in the second.

In the oestrous ewes, pentobarbital did not prevent or modify the expected LH surge. In the ovariectomized ewes, the drug, while not affecting the pulsatile release pattern of LH, reduced average LH levels to about half their control values (P < 0.001) when given in a dosage maintaining 3 or 4 h of light sleep; the 2-h dosage had no such effect.

These differential effects of pentobarbital indicate that LH secretion in ewes is regulated by more than one mechanism. In particular, our findings are consistent with a hypothesis that there are, in ovariectomized ewes, independent central regulatory mechanisms for the amount of LH released, and for the time pattern of its release.
THE IMPORTANCE OF SODIUM BALANCE ON THE EFFECT OF ANGIOTENSIN II ON ALDOSTERONE PRODUCTION
Authors: Aguilera Greti , White Allan , Marusic Elisa T.
Published: December 2008

The action of angiotensin II on the adrenal cortex can be modified by body sodium balance. The secretion rate of aldosterone was compared with the late biosynthetic pathway in dogs kept under different sodium states. The conversion of corticosterone (B) to aldosterone was significantly increased by the infusion of angiotensin II into sodium depleted dogs. ACTH infusion failed to increase the late aldosterone pathway in sodium depleted animals, even though the secretion rate increased by 10 times.

These results confirm previously indirect evidence that angiotensin II has a direct stimulatory effect on the late step of aldosterone biosynthesis. This stimulation does not appear to be the result of enzyme-substrate activation by aldosterone precursors.

The results favour the hypothesis that sodium balance can modulate the action of angiotensin II not only on the first steps, but that there is also a regulatory effect on the conversion of corticosterone to aldosterone.
AGE RELATED CHANGES IN FREE PLASMA TESTOSTERONE, DIHYDROTESTOSTERONE AND OESTRADIOL
Authors: Pirke Karl M. , Doerr Peter
Published: December 2008

The age related changes on free plasma testosterone (T), dihydrotestosterone (DHT) and oestradiol (Oe2) were determined in 82 healthy adult males. Forty-six subjects were between 22 and 61 years of age (group I), 36 between 67 and 93 years (group II).

The percentage of free, non protein bound hormone was determined by equilibrium dialysis of undiluted plasma against isotonic phosphate buffer at 37°C. Total hormone concentrations were measured by radioimmunoassay.

The percentage of free T was 2.24 % (median), 1.65–3.42 (95 percentiles) in group I and 1.65 % (1.24–2.26) in group II. The percentage of free DHT decreased from 1.17 % (0.80–2.03) in group I to 0.83% (0.52–1.55) in group II. The decrease in % free Oe2 was only very small: group I = 2.49% (2.13–2.96), ad group II = 2.31% (1.95–3.17).

The fall in free T by 43.3% from 12.2 ng/100 ml (6.74–25.0) in group I to 6.90 ng/ml (3.57–10.6) in group II was twice as high as that of total T, which decreased on an average by 20.6%. Free DHT decreased by 25.8 %: group I = 578 pg/100 ml (266–987), group II = 429 pg/100 ml (168–723), while total DHT was not significantly different between the two groups (–1.9%). Free Oe2 was increased in old age: group I = 42.4 pg/100 ml (26.0–69.4), group II = 55.7 pg/100 ml (35.8–118.9). The increase in free Oe2 by 31.4% was almost as high as that of the total Oe2 (46.9%).
LACK OF EFFECT OF HYPERGLYCAEMIA ON APOMORPHINE INDUCED GROWTH HORMONE RELEASE IN NORMAL MAN
Authors: Nilsson Karl Olof
Published: December 2008

Six healthy adult males were studied to evaluate the effect of apomorphine on growth hormone (GH) secretion under normoglycaemic and hyperglycaemic conditions.

Both under normoglycaemia and hyperglycaemia all subjects responded to the subcutaneous injection of 0.75 mg apomorphine hydrochloride with a marked increase in plasma GH concentration reaching a maximum after 30–60 min.

In control studies no significant changes in plasma GH were observed following the injection of physiological saline.

As apomorphine is considered a selective dopamine receptor stimulating agent, the results support the view that GH release in man can be modulated through a dopaminergic mechanism. The finding that the plasma GH rise after the administration of apomorphine is not suppressible by glucose indicates that apomorphine activates dopaminergic receptors localized distally in the hypothalamus or in the anterior pituitary. Amorphine in low dosage may be used clinically to test the capacity of the pituitary to release GH in man, at least in special cases.
OESTROGEN-INDUCIBLE UTERINE PROGESTERONE RECEPTORS. CHARACTERISTICS IN THE OVARIECTOMIZED IMMATURE AND ADULT HAMSTER
Authors: Reel J. R. , Shih Y.
Published: December 2008

In order to characterize the uterine progesterone-binding proteins of oestrogen-primed and unprimed, ovariectomized immature and adult golden hamsters, cytosols were incubated with [3H] progesterone and/or other steroids and analyzed by sucrose-glycerol density gradient ultracentrifugation. Progesterone-binding components with sedimentation coefficients of 7S and 4.5S were found in the uterine cytosols, but not in the cytosols from the hypothalamus, pituitary, diaphragm, or small intestine. Oestradiol-17β markedly elevated the level of 7S uterine receptor and this increase appeared to be due to new receptor synthesis, since actinomycin D and cycloheximide blocked this response. Fifty to 100 μg of oestradiol-17β per kg body weight was found to promote a maximum increase in the 7S macromolecular component. The 7S receptor showed a tendency to saturate at 1 × 10−7 m [1,2-3H] progesterone, indicating limited capacity. At a molar ratio of 100:1, unlabelled progesterone competed effectively for 7S and 4.5S [3H]progesterone binding, whereas 5α-pregnane-3,20-dione, oestradiol-17β and testosterone did not. Moreover, [1,2-3H] cortisol and [1,2-3H] corticosterone did not bind to the 7S receptor, implying steroid specificity. CI-628, a non-steroid oestrogen antagonist, completely prevented [6,7-3H] oestradiol-17β binding to its 8.5S uterine cytosol receptor, but was entirely without effect on 7S and 4.5S [3H] progesterone binding. Pronase, but not DNase or RNase, abolished 7S and 4.5S progesterone binding, suggesting that the binders are at least in part protein. Protamine sulphate and p-hydroxymercuribenzoate also obliterated 7S binding, implying that this receptor may be an acidic protein which contains sulfhydryl groups that are necessary for progesterone binding.
NON-IDENTICAL REACTION OF UNDISSOCIATED HCG AND HCG-β SUBUNIT WITH ANTI-HCGβ SERUM
Authors: Arends J.
Published: December 2008

Based on gel-filtration experiments, estimates of the content are given of undissociated human chorionic gonadotrophin (HCG) and HCG-β subunit in HCG preparations.

Radioimmunoassay of three HCG preparation using an antiserum against HCG-β subunit showed that the slope of displacement curves was dependent on the ratio of HCG-β subunit to undissociated HCG, the slope being steeper (negative) with increasing ratio.

The implication of this observation on the choice of a suitable standard for HCG-β radioimmunoassay is discussed.
INHIBITION OF PROLACTIN SECRETION BY ERGOT ALKALOIDS
Authors: Nasr H. , Pearson O. H.
Published: December 2008

The effect of various ergot alkaloids on prolactin (Pr) secretion in adult female rats was determined by radioimmunoassay. Ergocornine (ECO) and ergocristine (ECR) in doses of 0.25 to 1.0 mg lowered serum Pr markedly by 1 h with the effect persisting for 24 h at the larger doses. Several other ergots had similar effects while the dihydro derivatives had diverse responses. The pro-oestrous surge of Pr could be blocked by ECR or ECO without interfering with the oestrous cycle. ECO or ECR could suppress the rise in serum Pr induced by oestradiol benzoate (OeB) (5–50 μg) in oophorectomized rats. Perphenazine (PE) stimulation of Pr could be partially antagonized by ECO depending on dose and timing of injections. ECO 2 mg produced an abrupt cessation of lactation with concomitant fall in serum Pr, and ovine prolactin restored this function. Evaluation of pituitary Pr concentration in lactating and intact rats receiving ECO leads to the conclusion that release of Pr from the pituitary is affected. ECO 1 or 2 mg produced a regression of dimethylbenz(a)anthracene (DMBA) induced rat mammary tumours which could not be reversed by OeB 5 μg, with persisting low serum Pr. PE 1 mg was able to raise serum Pr and stimulated tumour growth. Several of the ergot alkaloids have a profound inhibiting effect on Pr secretion and may be used for studies on Pr action, as well as in medical therapeutics.
RADIOIMMUNOASSAY OF [8-ARGININE]-VASOPRESSIN
Authors: Merkelbach U. , Czernichow P. , Gaillard R. C. , Vallotton M. B.
Published: December 2008

A radioimmunoassay for [8-arginine]-vasopressin (AVP), previously described (Czernichow et al. 1975) has been used for the determination of antidiuretic hormone in a 4 ml urine sample. AVP is extracted from acidified urine with a cation exchanger (Amberlite CG 50) with an overall recovery of 72 %. The blank value measured in extracted samples of urine was 0.29 pg/ml ± 0.21 (sem) and calculated by extrapolation of the regression line of the recovery experiment was 0.49 pg/ml. The coefficient of variation within-assay was 13 % and between-assay 18%. Addition of the amounts of AVP found in each specimen of urine voided gave results nearly identical to those of the amounts found in 24 h pool of urine, indicating that the assay was not affected by changes in concentration of the other urinary components during the day. The daily urinary excretion of AVP measured in 34 subjects was found to be 34 ng in 17 women and 70 ng in 17 men, a significant difference. Urinary concentration and excretion rate of AVP rose during thirst test and during Carter-Robbins test performed in 13 healthy subjects. In the latter test it was observed that the women displayed a strikingly more pronounced AVP elevation after the osmolar stimulus than the men. In both sexes a significant correlation was found between AVP excretion rate and plasma osmolality as well as free water clearance. Three cases of complete or incomplete diabetes insipidus and potomania could be clearly differentiated according to the total output of AVP during the thirst test. Extremely high values of AVP were found in the urine of 5 subjects with Schwartz-Bartter syndrome associated with bronchogenic tumours.
EFFECTS OF OESTRADIOL-17β BENZOATE TREATMENT ON FRACTURE HEALING AND BONE COLLAGEN SYNTHESIS IN FEMALE RATS
Authors: Langeland Norvald
Published: December 2008

The influence of oestradiol-17β benzoate, 70 μg administered intramuscularly twice a week for up to four weeks, on collagen synthesis in fractured bones, was studied in young adult castrated female rats. The specific activity of [14C] hydroxyproline in the fracture region of the treated rats was constantly below that of the normal and the castrated control animals throughout the experimental periods. The percentage of incorporated 14C found as [14C] hydroxyproline was also reduced in the fracture regions of the oestrogen treated rats compared to the percentage observed in normal rats. During the first two weeks after fracture and the start of treatment, there was no differences in tensile strength of the fractures and no significant difference in collagen content of the fractured tibia of the 3 experimental groups. The weights of the unfractured tibiae in oestrogen treated rats were lower than those of the control animals. The findings suggest a "slow down" of collagen metabolism after administration of high doses of oestradiol.
PROGESTERONE, OESTRADIOL-17β AND TESTOSTERONE LEVELS IN THE FOLLICULAR FLUID OF TERTIARY FOLLICLES AND GRAAFIAN FOLLICLES OF HUMAN OVARIES
Authors: Kemeter P. , Salzer H. , Breitenecker G. , Friedrich F.
Published: December 2008

Radioimmunoassays of testosterone (T), oestradiol-17β (Oe2) and progesterone (P) in the fluid of a total of 47 follicles of different degrees of maturity gave the following mean values: T: 49 ng/ml, Oe2: 932 ng/ml, P: 999 ng/ml. In normal, atretic and cystic tertiary follicles not larger than 1 cm and without luteinized theca interna the following mean values were calculated: T: 54 ng/ml, Oe2: 502 ng/ml, P: 368 ng/ml. In six women mature and less mature follicles were compared, the former having significantly higher Oe2 and higher P values but significantly lower T values than the latter. Genuine Graafian follicles were observed four times, once after HMG stimulation; the values observed lay within the following ranges: T: 12–35 ng/ml, Oe2: 1900–4100 ng/ml, P: 156–6000 ng/ml. The difference in concentration compared with cubital-vein blood before ovulation was highest for Oe2, suggesting a particularly marked aromatinzing activity of the follicles of that phase of the cycle. The findings suggest that in the course of accelerated follicular ripening prior to ovulation both the aromatizing enzyme and 3β-hydroxysteroid-dehydrogenase are activated, resulting in a sharper rise in Oe2 and P. The profuse production of P causes a transistory lack of precursors for androgen and oestrogen production (T and Oe2 declines). In the course of an overall increase i steroid production during the luteal phase – which probably goes hand in hand with an increased supply of pregnenolone – there is not only a pronounced rise in progesterone but also a moderate increase in oestrogen production. The androgens are transformed more rapidly into oestrogens on account of the marked activity of the aromatizing enzyme in the corpus luteum and thus show a decline in the luteal phase.
CIRCANNUAL AND CIRCADIAN RHYTHMS IN PLASMA TESTOSTERONE IN FIVE HEALTHY YOUNG PARISIAN MALES
Authors: Reinberg Alain , Lagoguey Michel , Chauffournier Jean-Marc , Cesselin François
Published: December 2008

Every other month, during the course of 14 months, the circadian rhythm in plasma testosterone (among others variables) of 5 healthy males (26 to 32 years) was documented.

Subjects' synchronization: light-on at 7 ± 1 h; light-off at 23 ± 1.5 h during the whole year. Blood sampling 4-hourly, at fixed times during 28 h, for radioimmunological testosterone determinations. The cosinor method was used for statistical analyses.

An annual rhythm in the testosterone 24-h mean is detected (P < 0.025) with a peak in October (from 16 July to 26 December, with 95% confidence limits). Annual mean (± 1 se) = 759 (± 26) ng/100 ml. Peaktrough difference = 197 ng/100 ml (from 106 to 290 with 95% confidence limits).

The timing of the testosterone circadian peak, in the 24-h-scales also varies during the course of the year. The peak is found around 8 h in May and around 14 h in November, this phase-shift being statistically significant (P < 0.05).
PLASMA TESTOSTERONE LEVELS IN C57BL/6J MALE MICE: EFFECTS OF AGE AND DISEASE
Authors: Nelson James F. , Latham Keith R. , Finch Caleb E.
Published: December 2008

Plasma testosterone (T) was measured by radioimmunoassay in both healthy and diseased, mature (8–11 months) and senescent (29–31 months) C57BL/6J male mice. Pathological lesions in diseased mice included reticulum cell sarcoma and enlarged mesenteric lymph nodes. In healthy mice neither plasma T nor testicular weight differed between age groups. Median levels and 95 percentiles of plasma T in ng/ml were 1.12 (0.19–12.18) in mature mice and 1.17 (0–7.31) in senescent mice. In diseased mice testicular weight and the range of values of plasma T were significantly reduced. The marked decreased in plasma T and testicular weight in diseased senescent mice illustrates the importance of distinguishing between disease-related changes and effects of aging, per se.
ASYMMETRICAL GONADAL DIFFERENTIATION AND GONADOBLASTOMA
Authors: Coco R. , Chemes H. , Bergada C. , Kraizer Juan
Published: December 2008

A 1010/12 years old virilized girl with the syndrome of asymmetrical gonadal differentiation is reported. The patient had a negative sex chromatin and positive Y chromatin (bright fluorescent body of Y chromosome) in the buccal smear and 45,X/46,XY karyotype in the peripheral blood lymphocytes. An exploratory laparotomy showed a small uterus, two Fallopian tubes, a tumoural testis on the right side and a streak on the left side. Pathological examination revealed the presence of gonadoblastoma in both gonads. The Y chromatin was identified on histological sections only on the side of the testis, and was absent on the streak and its gonadoblastoma's nests.

The distribution of the different cell lines and the fluorescence of the Y chromosome is discussed in relation to gonadal differentiation and the occurrence of gonadoblastoma.
RNA, PROTEIN AND DNA SYNTHESIS STIMULATED BY TESTOSTERONE, INSULIN AND PROLACTIN IN THE RAT VENTRAL PROSTATE CULTURED IN CHEMICALLY DEFINED MEDIUM
Authors: Johansson Risto
Published: December 2008

In an organ type tissue culture of the rat ventral prostate in a chemically defined medium insulin (0.08 IU/ml) stimulated the synthesis of RNA within 6–12 h, the synthesis of protein within 6–12 h and the synthesis of DNA within 2–4 days. Testosterone (10−8 m) stimulated these synthetic processes somewhat more slowly: the synthesis of RNA within 12–24 h, protein within 12–24 h and DNA at 4 days. Rather high concentrations of insulin were needed while testosterone was effective at a physiological concentration. Prolactin (1000 ng/ml) stimulated the synthesis of RNA and protein, but not DNA, when added together with either testosterone or insulin, but was completely ineffective when added alone. The response times resembled those of insulin. The lower concentrations of prolactin were ineffective. Growth hormone, luteinizing hormone and follicle stimulating hormone did not stimulate the synthesis of RNA, protein or DNA even when added with testosterone. The results confirm the findings of the numerous in vivo experiments that the hypophyseal hormone prolactin has a direct effect on the ventral prostate.
IN VITRO STUDIES ON COLLAGEN METABOLISM IN METAPHYSEAL RAT BONE
Authors: Langeland Norvald
Published: December 2008

The effect of oestradiol-17β treatment on bone collagen metabolism in vitro was studied in metaphyseal rat bone. Rats were oophorectomized and subsequently treated for 3 weeks with different doses of oestradiol-17β. Bone pieces were incubated in a modified Krebs-Ringer bicarbonate medium for 6 h. Synthesis of [14C] hydroxyproline from [14C]proline and the incorporation of this amino acid into the bone samples was determined and the collagen synthesis and accretion rates calculated from these data. Collagen resorption rates were calculated from measured release of non-radioactive hydroxyproline to the medium.

Castration resulted in an increased rate of accretion and resorption of collagen. All doses of oestradiol tested in this study (1 to 20 μg per animal per day for 3 weeks) decreased both accretion and resorption rates to levels insignificantly different from those of the non-castrated control rats. Only the 2 μg treated group had significantly better collagen balance than the castrated untreated rats.
APPLICATION OF A RADIOLIGAND RECEPTOR ASSAY FOR DETERMINATION OF LUTEINIZING HORMONE IN HUMAN SERUM
Authors: Leidenberger F. A. , Willaschek R. , Pahnke V. G. , Reichert L. E.
Published: December 2008

A sensitive, specific and economic radioligand receptor assay is described for measurement of LH in human serum (RRA-LH). By means of ethanol fractionation or (NH4)2SO4-precipitation serum can be prepared for LH-quantitation and tested in the RRA-LH without interference of a nonspecific inhibiting substance present in untreated serum from various human sources. Treatment of serum with 8 % ethanol separates nonspecific inhibiting substances from LH, the latter remaining in the supernatant at this ethanol concentration.

The criteria of specificity are examined. The results of experiments designed to produce evidence for or against specificity suggest specificity of the RRA-LH.

Recoveries, as estimated by administration of [125I]hLH and unlabelled hLH to untreated serum samples are shown to be between 80 and 95 % for the ethanol fractionation procedure and between 65 and 75 % for the (NH4)2SO4-precipitation method.

The ethanol fractionation procedure is preferred for routine serum-LH determination because of its simplicity, speed and higher recoveries.

Ethanol-treated sera from post-menopausal women show, on average, higher RRA-LH concentrations than ethanol-treated sera from young women. RRA-LH values are consistently higher than LH-values found by radioimmunoassay (RIA-LH).

The LH-concentrations in sera from two menstrual cycles and from two LH-releasing hormone tests are measured by RRA-LH and by RIA-LH. Similarities and discrepancies of the LH-profiles found by the two assay systems are described.
STUDIES ON THE PATTERN OF CIRCULATING STEROIDS IN THE NORMAL MENSTRUAL CYCLE
Authors: Guerrero R. , Aso T. , Brenner P. F. , Cekan Z. , Landgren B.-M. , Hagenfeldt K. , Diczfalusy E.
Published: December 2008

In an attempt to analyze the multiple changes and interactions in circulating steroid levels in the peri-ovulatory and peri-menstrual periods, the plasma levels of immunoreactive luteinizing hormone (LH), progesterone and unconjugated pregnenolone, dehydroepiandrosterone, testosterone, oestradiol and oestrone were assayed daily during a complete cycle in 17 normally menstruating women. In 14 of the 17 subjects studied androstenedione and unconjugated dihydrotestosterone were also estimated. The day of the LH-peak and the first day of menstruation, respectively, were used to synchronize the peri-ovulatory and peri-menstrual plasma levels of the various steroids.

With the exception of dehydroepiandrosterone and dihydrotestosterone, the plasma levels of all steroids exhibited significant, but different changes during the cycle. Testosterone levels showed a slight but significant increase around the LH-peak, whereas the levels of pregnenolone and androstenedione were higher in the post-ovulatory than in the pre-ovulatory periods. The levels of oestradiol and oestrone, as well as the ratios of oestradiol to oestrone gradually increased from the low values observed in the early proliferative phase to pre-ovulatory peak values. The relationship between peaks of oestradiol and oestrone and that of LH exhibited great individual variation. The same was true for the individual oestradiol to oestrone ratios. The combination of several steroidal signals did not improve the predictive value of the analyses. However, an increase of individual progesterone values by at least 0.35 ng/ml from the day preceding the LH-peak to the day of the LH-peak was observed in 13 of the 17 subjects. It is suggested that for the early detection of the LH surge and prediction of the subsequent ovulation daily assays of plasma progesterone are of more value than the assay of the other steroids investigated.
THE EFFECT OF INTRA-UTERINE CONTRACEPTIVE DEVICES ON THE OESTROGEN-INDUCED INCORPORATION OF [3H-5]URIDINE INTO RNA BY THE RAT UTERUS
Authors: Dada O. A. , Adadevoh B. K.
Published: December 2008

A length of copper or stainless steel wire or of silk thread suture was inserted as an intra-uterine device (IUD) for 3 days in the right uterine horn of ovariectomized virgin female rats. The left horn served as a control. The control rats were ovariectomized but had no IUD inserted.

The in vitro incorporation of [3H-5]uridine into uterine RNA was significantly inhibited (P < 0.05) in copper-bearing horns compared to control horns, while silk and steel devices had no inhibitory effect, thus indicating an effect of intra-uterine copper on oestradiol-induced uterine metabolism. The insertion of an intra-uterine device had no significant effect on uterine wet weight, DNA content or on the uptake of [3H-5]uridine into the nucleotide pool.
BODY WEIGHT REGULATION IN FEMALE RATS FOLLOWING NEONATAL TESTOSTERONE
Authors: Dubuc Paul U.
Published: December 2008

Neonatal testosterone treatment of female rats led to an increase in body weight and skeletal growth and produced evidence of altered ovarian function over a 76 day period following treatment. Bilateral ovariectomy performed eleven weeks after neonatal treatment increased the rate of body weight gain of both testosterone propionate- and oil-treated groups, but no differences in the increased rates of weight gain were evident between groups over a five week post-ovex observation period. Subsequently, long-term oestrogen replacement therapy, via subcutaneous Silastic implants, produced equal reductions in the rates of body weight gain and somatic growth of both early testosterone- and oil-treated ovariectomized groups. In spite of the marked effects of these manipulations on body weight and skeletal growth, no significant differences were noted in the Lee Index of obesity between androgenized and the appropriate non-androgenized control rats at any interval of the experimental period. These results indicate that neither ovarian hormones nor an altered sensitivity to oestrogen of body weight regulatory mechanisms are important in the increased body weight that follows perinatal testosterone treatment. Additionally, the present data add support to previous work which has suggested that a general increase of somatic growth rather than 'obesity' provides the major contribution to the elevated body weights of androgenized female rats.
INFUSIONS OF hFSH AND hLH IN NORMAL MEN
Authors: Kjeld J. M. , Kuku S. F. , Harsoulis P. , Fraser T. R. , Puah C. M. , Joplin G. F.
Published: December 2008

Standardized 4 h intravenous infusions of human follicle stimulating hormone (hFSH) and/or human luteinizing hormone (hLH) were given either separately or combined to 7 normal male volunteers. The infusions raised the serum gonadotrophin levels at least 10 (FSH) and 18 (LH) times above the basal ones. Serum testosterone (T) levels were measured serially before, during and after the infusions and, in 4 subjects, during a corresponding period of another normal day. During a normal or basal 24 h period fluctuations were seen and also a circadian rhythm with lower levels in the evening. The infusion of hFSH alone (3 subjects) did not alter the serum T levels. The infusion of hLH alone in 2 subjects raised serum T levels by 17% and 55% over those of the basal day. The combined FSH/LH infusion caused a significant rise (35–68%) in 4 subjects and greater rise in 2 of them than after infusion of the hLH alone. The serum T responses were gradual, reaching a maximum 7–8 h after the end of the infusion.
THE STIMULATION OF GROWTH HORMONE RELEASE BY ACTH AND ITS INHIBITION BY SOMATOSTATIN
Authors: Köbberling J. , Jüppner H. , Hesch R. D.
Published: December 2008

The rapid injection of 0.5 or 1.0 mg of tetracosactid (Synacthen®) was followed by a distinct increase of plasma growth hormone (GH) within 30 or 45 min in 5 of 7 normal volunteers. A second control test was performed in 3 of the 5 "responders" and 1 "non-responder" and showed a consistent reaction in all of them. The tests were then repeated in the 5 "responders" during an infusion of somatostatin (150 μg/h) and the GH response was totally abolished (3 subjects) or markedly reduced (2 subjects). Thus the ACTH induced GH release behaves in a manner similar to most other physiological or pharmacological stimuli of GH release. The cortisol output after ACTH was not altered by somatostatin.
IODOTHYRONINE CONTENT OF HUMAN THYROID ALBUMIN
Authors: Thomas-Morvan Colette
Published: December 2008

Stable thyroid hormones (T4 and T3)1) have been demonstrated in pure albumin isolated from normal human thyroid tissue iodinated in vivo. Five samples of albumin were separated from other thyroid proteins by acrylamide gel electrophoresis. After pronase hydrolysis, the content of Thyroid hormones was measured chemically (T4 + T3) as well as by competitive radioactive measurement (T4) and radioimmunoassay (T3). The purity of the albumin and validity of these measurements were confirmed by different techniques.

The synthesis of thyroid hormones is not therefore a property unique to Tg and may occur in albumin. However the amount of iodothyronines in the albumin (average 0.004 residue per molecule) is much less than that found in Tg (0.5 residue per molecule). In the albumin as in Tg the number of hormone residues per molecule is proportional to the number of atoms of iodine. At an equivalent iodine concentration, the albumin seems capable of forming the thyroid hormones as well as Tg. The difference between these two proteins, in their capacity to synthesize thyroid hormones, seems to depend on their capacity for iodination. This difference of iodination does not seem to be linked with the number of tyrosyl residues, but might be related to the position of these residues.
DETERMINATION OF PLASMA ALDOSTERONE IN CHILDREN BY THIN LAYER CHROMATOGRAPHY AND RADIOIMMUNOASSAY
Authors: Parth K. , Zimprich H. , Brunel Roswitha
Published: December 2008

An accurate and relatively simple radioimmunoassay for the determination of aldosterone concentration in peripheral plasma has been developed. 0.5–2.0 ml plasma with added [1,2-3H] aldosterone is extracted with dichloromethane. Purification of the extract is achieved by thin layer chromatography in the system benzene-acetone 1:1. Recovery of [1,2-3H] aldosterone is 58 ± 6 (sd) %. Bound and free fractions are separated by dextran-coated charcoal.

The intra-assay reproducibility is 8.8 % and the inter-assay reproducibility varies from 11.4–16.1 %. The sensitivity of the assay for a 5 ml plasma sample can be put at 0.2 ng/100 ml.

Normal values determined in 52 healthy children of different age groups are presented. Furthermore the aldosterone stimulating effect of low sodium diet (17 children), severe and prolonged vomiting (19 children) and synthetic ACTH (10 children) has been studied by our modified method.
IN VITRO MODIFICATION OF RAT ADRENAL ZONA FASCICULATA/RETICULARIS FUNCTION BY THE ZONA GLOMERULOSA
Authors: Vinson G. P. , Whitehouse Barbara J.
Published: December 2008

Following earlier findings, the possibility that the zona glomerulosa of the rat adrenal cortex may modify inner zone function was investigated. In a series of in vitro experiments designed to test this hypothesis it was found that:

1. Inner zone preparations gave significantly more steroid than either glomerulosa tissue incubated alone, or (for the first 40 min of a two hour incubation), an equivalent amount of whole adrenal tissue. Whole tissue yields were greater than glomerulosa alone only at the 120 min point. At no time did the whole tissue output approach the total anticipated by addition of separate inner zone and glomerulosa yields.

2. In 20 min incubations, inner zone steroid output generally could be depressed by the addition of a glomerulosa preincubation medium (PIM), or a steroid extract of a glomerulosa PIM, or by the addition of 100 ng aldosterone. Inner zone PIM had less effect.

3. Higher concentrations of aldosterone gave increased inhibition of inner zone corticosteroid production. The results indicated that only a part of the total corticosterone output was aldosterone sensitive in this way.

4. More specific analysis of the steroids showed that yields of corticosterone from endogenous precursors were depressed by aldosterone, but deoxycorticosterone and 18-hydroxydeoxycorticosterone were not. In the same incubations the presence of aldosterone had no effect on the formation of these three products from [3H]pregnenolone.

In total the results suggest that the presence of the glomerulosa may affect inner zone function by inhibiting the secretion of corticosterone formed from endogenous precursors. It is possible that aldosterone is the agent of this effect.
GROWTH HORMONE AND SOMATOMEDIN BEHAVIOUR IN THE NEWBORN
Authors: Giordano Giulio , Foppiani Edilio , Minuto Francesco , Perroni Davide
Published: December 2008

Human growth hormone (HGH) and somatomedin (Sm) concentrations have been studied in a group of newborns.

Plasma HGH values were 41.17 ± 24.26 (sd) ng/ml (14.00-90.00 ng/ml) and the Sm value was 0.59 ± 0.43 (sd) U/ml (0.18–1.8 U/ml); the difference between these values and the ones observed in normal adults (2.45 ± 2.53 (sd) ng/ml and 1.16 ± 0.28 (sd) U/ml respectively) were statistically significant.

While growth hormone values were higher than in normal adult controls, somatomedin was significantly decreased. It is possible that the dissociation between human growth hormone and somatomedin in newborn could reflect a reduced biosynthesis of the somatomedin-generating system and consequently a lack of a feed-back control on GH exerted by somatomedin.
HETEROLOGOUS RADIOIMMUNOASSAY FOR BOVINE FOLLICLE-STIMULATING HORMONE AND ITS APPLICATION DURING THE OESTROUS CYCLE IN CATTLE
Authors: Schams D. , Schallenberger E.
Published: December 2008

A specific heterologous radioimmunoassay for bovine follicle-stimulating hormone (bFSH) has been developed using guinea pig antiserum to ovine FSH with radio-iodinated ovine FSH. Slight cross-reactions with bovine TSH and LH could be eliminated by adding bovine TSH and LH to each tube during the assay. The labelling method with lactoperoxidase turned out to be more useful than the chloramine-T method. Inhibition curves obtained with male and female bovine plasma were parallel to those obtained with the bovine standard preparation. Exogenous bFSH could be quantitatively recovered from 200 μl of plasma or serum with a mean of 101.7 ± 7.7 %. The intra-assay coefficient of variation (CV) was ≦ 6 %. The inter-assay CV was 13.5 %.

Sensitivity was 70 ng/ml NIH-FSH-B1. Mean plasma concentrations of FSH (NIH-FSH-B1) during the oestrous cycle were 303 ± 101 ng/ml. When plasma samples were collected in 6 h intervals from 17 oestrous cycles from 13 regularly cycling heifers and cows, a significant FSH peak occurred just before and during oestrus and coincided with the pre-ovulatory LH peak. Further FSH elevations could be measured on day 4, 8 and 12 after ovulation and 5 and 3 days before ovulation and showed a rhythmic pattern of four day intervals approximately.
STIMULATORY EFFECT OF FSH IN VITRO ON THE EXTRACELLULARLY ACTIVE CYCLIC AMP PHOSPHODIESTERASE IN THE PREPUBERTAL RAT OVARY
Authors: Selstam Gunnar , Rosberg Sten
Published: December 2008

Intact prepubertal rat ovaries were incubated with radioactively labelled adenosine 3,′5′-cyclic monophosphate (cAMP) in Krebs bicarbonate buffer containing glucose. The rate of degradation of cAMP was determined by measuring the radioactivity in the medium after precipitation with Ba(OH)2 and ZnSO4. The fate of the nucleotide was followed by measuring the products in the incubation medium. Paper chromatography was used for the separation and identification of these products. It was found that cAMP was degraded to AMP, which in turn was degraded to inorganic phosphate (Pi) and adenosine. An uptake of labelled products was also observed. NIH-FSH-S9 (10 and 100 μg/ml), but not NIH-LH-B8 (0.1–100 μg/ml), increased the degradation of cAMP. Concomitantly, an increased accumulation of labelled adenosine and Pi as well as an increased uptake of labelled products were seen. Kinetic studies with low concentrations of cAMP (0.125–0.025 μmol/l) revealed an apparent Km value of 0.12 μmol/l for the phosphodiesterase (PDE) activity. FSH significantly changed the slope of the curve in the Lineweaver-Burk plot by increasing the PDE activity. The increased PDE activity in the presence of FSH is discussed in relation to earlier findings of differences in action between LH and FSH on the cAMP system in the prepubertal rat ovary.
SIALIC ACID AND SIALIDASE ACTIVITY IN HUMAN ENDOMETRIAL TISSUE, UTERINE FLUID AND PLASMA UNDER DIFFERENT CONDITIONS OF UTERINE DYSFUNCTION
Authors: Ganguly S. , Sarkar D. , Ghosh J. J.
Published: December 2008

Sialic acid content in endometrial tissue and sialidase activity in the endometrium, uterine fluid and plasma has been measured in normal and in conditions of uterine dysfunctions. It has been observed that an antagonistic effect exists between endometrial sialidase and sialic acid content, but in all the cases of uterine dysfunctions, the sialidase activity in uterine fluid and plasma decreases, whereas it increases during pregnancy.
RNA METABOLISM IN CHICK OVIDUCT DURING OESTROGEN STIMULATION
Authors: Hemminki Kari
Published: December 2008

The amount and the labelling of RNA were studied in chick oviduct after secondary stimulation of pre-treated chicks with oestrogen.

The weight of the oviduct increases over 2 fold in 20 h of oestrogen action using a dose of 1 mg. During the hormonal treatment the amount of cytoplasmic and nuclear RNA increases about 3 and 1.5 fold, respectively. The amount of poly(A)1) containing RNA increases somewhat less than that of RNA lacking poly(A). The proportion of poly(A) containing species of the total cytoplasmic and nuclear RNA decreases from 5.8 % to 4.4 % and from 7.8 % to 6.3 %, respectively. Hydroxyurea largely prevents the effect of oestrogen in increasing the amount of RNA.

Incorporation of [3H]uridine in RNA in vitro is stimulated about 2.5 fold in cytoplasmic RNA lacking poly(A) and only 1.2 fold in RNA containing poly(A) in 20 h of oestrogen action. In nuclear RNA the labelling of the two species is stimulated about 1.7 fold. Hydroxyurea fails to interfere with the oestrogen-induced stimulation in the labelling of RNA. Cytoplasmic and nuclear RNA containing poly(A) is distributed in a peak of about 20 S in agarose-acrylamide gels.
DIURNAL TESTOSTERONE AND 17α-HYDROXYPROGESTERONE IN PERIPHERAL PLASMA OF YOUNG POST-PUBERTAL BULLS.
Authors: Thibier M.
Published: December 2008

Testosterone1) and 17α-hydroxyprogesterone were measured in the peripheral plasma of 6 young post-pubertal bulls of 1 year of age, by separate radioimmunoassays. Samples were collected every hour for 25 h at the beginning of each of four seasons. On a separate occasion blood samples were collected from one bull every 10 min for 2 h.

As a result of the study, testosterone and 17α-hydroxyprogesterone appeared to be secreted episodically. These two steroid peaks showed good correlation. Each 24 h period showed its own characteristic pattern of pulsatile changes. Episodic secretion seems to be progressive rather than rapid and short lived.

No real circadian rhythm was observed but at about 10.00 a. m. a trough in these steroid secretions occurred. This was followed by an increase in peripheral plasma concentration. These troughs occurred at all seasons after the morning feed and while semen was being collected in the performance test station.
THE EFFECTS OF CASTRATION ON BODY COMPOSITION, ADIPOSE TISSUE CELLULARITY AND LIPID AND CARBOHYDRATE METABOLISM IN ADULT MALE RATS
Authors: Kral John G. , Tisell Lars-Eric
Published: December 2008

Gonadal hormones affect body composition, food intake, weight gain and serum lipids in numerous species including man. In this study, mature male Sprague-Dawley rats were castrated or sham-operated at 16 weeks of age. During the 6-week observation period with weekly records of food intake and weight gain, these parameters were significantly lower in the castrated group. The decrease in food intake in this group could not account for the difference in body weight between the groups, indicating a lower feed utilisation in the castrates.

At sacrifice accessory reproductive organs, the levator ani muscle, thymus and adrenals were dissected for determination of organ weight and histology, revealing significant reductions in the accessory reproductive organs and levator ani of the castrates. The thymus was significantly heavier in the castrated animals. No differences were found in the adrenals. Two of the sham-operated animals had signs of accidental functional castration. The proportion of body cell mass and total lipid of the carcass was the same in both groups. Significant reductions in adipocyte weights were found in the epididymal depots of the castrated rats.

Blood samples taken at sacrifice in pentobarbital anaesthesia were analysed for glucose, insulin, triglycerides, cholesterol, FFA, glycerol and protein. Statistically significant reductions in triglycerides and protein were recorded in the castrated animals without any significant changes in the other parameters studied.

The results are discussed with reference to the age of castration and the importance of the reduced food intake in castrated animals.
CONTROL OF THE MITOTIC ACTIVITY IN THE RAT SEMINAL VESICLE BY "CHALONE"
Authors: Söderström Karl-Ove , Tuohimaa Pentti
Published: December 2008

One month after castration male rats were injected daily with 2 × 50 μg of testosterone. Starting before the highest mitotic activity of seminal vesicles, 3 injections of normal seminal vesicle extract were given into the lumen at 3 h intervals. The contralateral seminal vesicle was injected with rat liver extract. Tritiated thymidine was given intravenously. The labelling index of the seminal vesicles was determined by means of radioautography.

The crude supernatant of seminal vesicle was the most effective to inhibit the mitotic activity of the seminal vesicles. The decrease was on an average 34 per cent. The liver extract did not influence the mitotic activity. When the seminal vesicle extract was fractionated by Sephadex G-25, the largest fraction (M. W. > 3000) showed the highest inhibitory activity, whereas the smallest fraction (M.W. < 1000) was ineffective. The inhibiton of mitosis can also be induced by an unspecific factor, since pronase showed slight inhibitory action on seminal vesicle mitosis. However, the seminal vesicle extract had no inhibitory action on the epidermal mitotic activity.
THE EFFECT OF CYPROTERONE ACETATE ON THE PLASMA GONADOTROPHIN RESPONSE TO GONADOTROPHIN RELEASING HORMONE
Authors: Donald Richard A. , Espiner Eric A. , Cowles R. John , Fazackerley Joy E.
Published: December 2008

Cyproterone acetate (100–150 mg daily) was administered to 8 male patients with excessive libido. Within 3 months a significant fall (P < 0.02) in plasma testosterone was demonstrated. The plasma luteinising hormone (LH) and follicle stimulating hormone (FSH) responses to gonadotrophin releasing hormone (LH/FSH-RH) were also significantly impaired (P < 0.05). A direct correlation between the resting plasma testosterone level and the LH response to LH/FSH-RH was demonstrated (r = 0.743). It is concluded that the fall in plasma testosterone levels in patients receiving cyproterone acetate may be attributed to suppression of LH release, rather than an antiandrogen effect on the testis or hypothalamus.
INCONSISTENCY OF THE TIBIA TEST FOR ESTIMATING GROWTH HORMONE IN CRUDE PITUTARY EXTRACTS
Authors: Somana Reon , Evans Edward S. , Ching Melvin , Evans Alison B. , Trakulrungsi Chatchai
Published: December 2008

The complement fixation immunoassay (CFIA) was used for quantitating growth hormone (GH) in crude anterior pituitary extracts from rats subjected to thyroidectomy with or without cortisol and exogenous GH administration. The results obtained from this study were compared with pertinent bioassay (tibia test) results or correlated with the pituitary acidophil cell counts. Whereas it has been reported that pituitary GH levels are normal by the tibia test at 2 weeks after thyroidectomy, the highly specific CFIA method showed an actual 87 % decrement which correlated well with the reduction in acidophils. In addition, the apparently normal content of GH after cortisol administration to thyroidectomized rats, as measured by the tibia test, was contradictory to the very low acidophil population and to the marked reduction in pituitary GH content as measured by the CFIA. Furthermore, theoretical tibia responses illustrate the inconsistency of the bioassay in different experimental conditions. If, as previously suggested, the content of thyrotrophin (TSH) in the crude pituitary extracts renders the bioassay of GH a dubious procedure, then the superiority of immunoassay is obvious.
THE DIURNAL VARIATION IN RENAL IODIDE EXCRETION RATE IN RABBITS
Authors: Vadstrup Steen , Bojsen Jørgen
Published: December 2008

The diurnal variation in renal iodide excretion rate was determined in unrestrained female rabbits by means of either a conventional clearance technique or a continuous monitoring of the whole body disappearance of iv injected 125I-iodide using an implanted Geiger-Müller detector.

A distinct diurnal rhythm was detected in the disappearance rate of 125I-iodide. A slow disappearance rate occurred from 12 p. m. to 6 a. m. (darkness from 5 p. m. to 5 a. m.).

The values of iodide excretion rate obtained by both methods were consistent like in humans with an excretion fraction of 0.3 for iodide in rabbits.

In rabbits weighing 3-4 kg the renal iodide excretion rates were 5-7 ml/min during the rapid phase and 3-4 ml/min during the slow phase.
THE IMMEDIATE EFFECT OF TSH ON RENAL IODIDE EXCRETION RATE IN RABBITS
Authors: Vadstrup Steen , Bojsen Jørgen
Published: December 2008

The renal iodide excretion rate was determined in unrestrained female rabbits by means of conventional clearance technique or continuous monitoring of the whole body disappearance of iv injected 125I-iodide using an implanted Geiger-Müller detector.

The immediate effect of pharmacological doses of bovine TSH was studied by both methods and a significant decrease in iodide excretion rate was recorded following the administration of a single TSH dose of 4 IU. The effect of TSH lasted 3–6 h. Injection of 10–20 μg TRH caused a transient delay in iodide disappearance (30–50 min) while 2–20 μg triiodothyronine iv or sc had no immediate effect on the iodide disappearance.
SERUM GROWTH HORMONE RESPONSF TO BROMOCRIPTINE DURING A GLUCOSE TOLERANCE TEST IN ACROMEGALY
Authors: Cassar J. , Mashiter K. , Sullivan G. , Joplin G. F.
Published: December 2008

Serum growth hormone was assayed in eighteen acromegalic patients during an oral glucose tolerance test with and without 2.5 mg bromocriptine.

The serum growth hormone levels during the glucose tolerance test with bromocriptine, although significantly lower at two sampling times, do not show any distinct pattern. We conclude that such an acute test will not distinguish the patient who might respond to long term treatment with bromocriptine.