bluuebunny/crossref_metadata_2025 huggingface dataset:
Gonadotrophins and ovarian steroids in cattle.
Authors: Schallenberger E.
Published: December 2008

Abstract. Pulsatile LH and FSH release from the pituitary gland of 8 post-partum dairy cows was assessed in series of frequent bleedings (every 20 min for 12 h) performed in about weekly intervals from day 4 through day 32 post partum (pp).

The frequency of short-term secretion of LH increased during individually varying time periods (1.5–5 weeks) from about 1 pulse/4 h to about 1 pulse/1.25 h prior to the re-establishment of luteal function. FSH pulses (average frequency 1 pulse/2 h) were always released concomitantly with LH, but extra FSH pulses occurred in between. Interpulse intervals of LH and FSH (80 ±4 vs 82 ± 7 min) merged prior to the resumption of cyclicity. LH and FSH pulse frequencies remained slightly slower during this first periovulatory period pp than during pro-oestrus and oestrus of regular cycles; also, with one exception, no visible signs of oestrus were expressed. Despite low progesterone concentrations during the first luteal phase there was strong negative feedback mainly on LH, thus considerably prolonging the intervals between consecutive LH pulses (up to 620 min) whereas FSH release remained much faster (up to 270 min interpulse interval). LH interpulse intervals tended to be longer during short compared to normal length cycles post partum (420 ± 107 vs 285 ± 51 min) in the presence of only slightly altered FSH release (154 ± 37 vs 107 ± 7 min).

As the pituitary gland is able to secrete already early pp frequent pulsatile FSH contrary to LH, a selective suppression of LH including a maximal sensitivity to the negative feedback action even of low ovarian steroid concentrations and a lack of the positive feedback mechanism during an initial period have to be postulated. The ovarian-uterine unit seems to play a major role in the timing of the resumption of unimpaired reproductive functions post-partum.
Gonadotrophins and ovarian steroids in cattle.
Authors: Schallenberger E. , Prokopp S.
Published: December 2008

Abstract. The re-establishment of the positive feedback action of oestradiol-17β on both gonadotrophins was assessed in 20 dairy cows receiving three challenges once every 20 days from parturition through day 55 post partum (pp). One mg oestradiol-17β-benzoate dissolved in 5 ml oil was given im every 5 days to groups of 5 cows each. Blood was collected from the jugular vein every 3 – 12 h from 2 days before until 2 days after the injection.

No effect of oestradiol-17β on the LH release was exerted at parturition or day 5 pp. A stimulation of LH release started to occur in the majority of cows by day 10 pp. Two types of preovulatory like surges could be elicited: low magnitude LH releases lacking any concomitant FSH increase and parallel high magnitude LH and FSH surges. No cow expressed heat when exhibiting a weak LH surge before day 30 pp and only 30% thereafter. All cows showed oestrus when exhibiting parallel high magnitude LH/FSH surges after day 20 pp but only 40% on days 10 and 15 pp. Progesterone concentrations >0.5 ng/ml prevented the positive feedback action of oestradiol on LH and FSH. An initial negative feedback on FSH was exerted throughout the entire post-partum period comprising the luteal phase.

We conclude from these results that a certain minimum threshold frequency of endogenous LH secretion is necessary to allow oestradiol-17β to evoke its unimpaired stimulatory feedback action after an initial period of pituitary refractoriness during the early puerperal anoestrus and acyclic period.
A possible role of clomiphene citrate in the control of pre-ovulatory LH surge during induction of ovulation
Authors: Terakawa Naoki , Shimizu Ikuya , Tsutsumi Hirohisa , Aono Toshihiro , Matsumoto Keishi
Published: December 2008

Abstract. A possible role of clomiphene citrate (clomiphene) in the control of ovulation in anovulatory women was investigated. Since a single ip administration of 5 μg oestradiol-17β (E2) to long-term ovariectomized rats did not induce LH surge, the following studies were designed to determine whether pretreatment with clomiphene followed by administration of E2 could induce LH surge in the ovariectomized rats. Changes in cytoplasmic and nuclear oestrogen receptors (ER) were also examined in the pituitaries of these animals. An ip injection of 200 μg clomiphene suppressed serum LH levels significantly for 72 h. The clomiphene injection rapidly caused an elevation of nuclear ER with a concomitant depletion of cytoplasmic ER level in the pituitary and the ER levels remained almost unchaged for 72 h. An administration of E2 12 or 24 h after the clomiphene injection had no significant effects on either the serum LH levels or the cytoplasmic and nuclear ER levels, compared with those induced by clomiphene alone. However, LH surge and the depletion of nuclear ER in the pituitary occurred 24 h later when E2 was injected 48 h after the clomiphene administration. The E2-induced LH release seems to be induced by a replacement of clomiphene by E2 on the nuclear receptor complex. These results suggest that clomiphene may exert actions directly on the pituitary gland to augment oestrogeninduced LH release.
Effect of metoclopramide-A dopaminergic blocker and endogenous cortisol on TSH secretion in critically ill men
Authors: Haim S. Ben , Kahana L. , Bentur Y. , Sheinfeld M. , Levy L. , Laor A. , Bursztein S.
Published: December 2008

Abstract. In 17 critically ill men, low levels of FT4, TT4, TT3 and elevated levels of rT3 and cortisol were found. In spite of the low levels of circulating thyroid hormones, TSH levels of the critically ill men were significantly lower than those of the control group, with no correlations to the high cortisol levels. After iv injection of metoclopramide (MCP), a dopamine (DA) receptor blocker, the TSH and prolactin (Prl) increments in the critically ill patients were significantly lower than in the controls. No correlation was observed between basal cortisol levels and integrated TSH response to MCP. It is suggested that increased DA tone or high cortisol levels are not responsible for the lower basal TSH levels and for the blunted TSH or Prl responses to MCP in the critically ill. High levels of cortisol may be responsible for the altered TT4 peripheral metabolism to TT3 and rT3 in these patients.
Genetics and clinical significance of thyroxine binding globulin deficiency, an analysis of seven families
Authors: Kollind M. , Iselius L. , Pettersson T. , Adamson U. , Carlström A.
Published: December 2008

Abstract. Seven families, ascertained through probands with undetectable levels of thyroxine binding globulin (TBG) were studied from clinical and genetic points of view. The blood levels of TBG, thyroxine binding prealbumin (TBPA), thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) were determined in altogether 128 family members. The concentration of free thyroxine (FT4) was calculated from the concentrations of T4, TBG and TBPA. Only men (n = 15) were found to have total TBG deficiency. Their TSH levels were within normal range and they did not show any clinical symptoms of thyroid dysfunction. The mothers and daughters of the affected men had significantly lower TBG levels than control women. Segregation analysis performed on 46 nuclear families showed significant evidence for an X-linked additive mode of transmission and an additional multifactorial component with heritability 0.47.
Effects of somatostatin on the behaviour of thromboxane B2 and β-thromboglobulin in type I diabetes
Authors: Gragnoli G. , Signorini A. M. , Tanganelli I.
Published: December 2008

Abstract. Pharmacological studies have shown that the addition of somatostatin to insulin promotes a more rapid recovery from diabetic ketoacidosis. However, contradictory results have been reported concerning the action of somatostatin on platelet function, frequently deranged in diabetes. Therefore the plasma levels of thromboxane B2, a stable metabolite of proaggregatory thromboxane A2 and of β-thromboglobulin, a marker of platelet activation, were studied in 9 control subjects and in 13 insulin-dependent diabetic patients before and during somatostatin injection, administered as an initial 250 μg iv bolus followed by infusion of 300 μg over 3 h. In both groups, after somatostatin infusion thromboxane B2 and β-thromboglobulin levels showed, respectively, a progressive fall and an increase up to the second hour. Over the next hour thromboxane B2 increased and μ-thromboglobulin decreased but their levels did not return to basal values. During this experiment β-thromboglobulin plasma values in diabetic patients did not differ from those of control subjects. In contrast, thromboxane B2, decreased in relation to pharmacological treatment, maintained elevated levels. Our data, however, demonstrate that the dose of somatostatin used, produced in the diabetic patients a normal fall of thromboxane B2 in terms of percentage of base-line values, but increases of β-thromboglobulin lower than in control subjects. It is suggested that platelet function should be evaluated when somatostatin is used in the treatment of poorly controlled type I diabetes.
A somatostatin analogue inhibits chondrosarcoma and insulinoma tumour growth
Authors: Reubi J. C.
Published: December 2008

Abstract. The in vivo effects on tumour growth of a potent somatostatin analogue, SMS 201-995 [H-(D)Phe-Cys-Phe-(D)Trp-Lys-Thr-Cys-Thr-(ol)], were measured in two characterised transplantable tumours:

the Swarm rat chondrosarcoma, known to be insulin-, growth hormone (GH)-, somatomedin- and corticosteroid-dependent,

a hamster insulinoma, bearing specific high affinity somatostatin receptors.

SMS 201-995 (1.25 mg/kg/day) given for 25 days to rats bearing freshly transplanted chondrosarcomas inhibited tumour volume by 48%. A significant tumour growth inhibition was measured also in well developed tumours treated with high doses of SMS 201-995 (1.25 mg/kg/day) for 7 days. In the treated animals, GH was significantly inhibited.

In hamsters bearing a freshly transplanted insulinoma, the daily application of SMS 201-995 (200 μg/kg/day, sc) for 33 days could significantly inhibit the growth (as measured by tumour volume) of the tumour. A moderate inhibitory effect of SMS 201-995 on the growth of well grown insulinomas could also be observed.

This study shows that SMS 201-995 under the present experimental conditions has a moderate but significant growth inhibitory effect in two different transplantable tumour models. In the rat chondrosarcoma, the effect of SMS 201-995 is probably indirect, due to inhibition of GH, somatomedin and insulin. In the hamster insulinoma, the effect is possibly due to a more direct action of SMS 201-995 on specific somatostatin receptors present in this tumor.
Relaxin-induced changes in adenosine 3',5'-monophosphate levels in the human cervix
Authors: Norström Anders , Wiqvist Ingrid
Published: December 2008

Abstract. The effects of porcine relaxin on the levels of cAMP in human cervical tissue were studied in vitro. The specimens were obtained by needle biopsy from women undergoing hysterectomy, legal abortion in the first trimester or elective Casearean section at term, and were incubated in Krebs-Ringer buffer for 15 min in the presence of porcine relaxin (5 μg/ml, 3000 GPU/mg). cAMP was determined using a modified protein binding assay. The concentration of cAMP was higher in pregnant than in non-pregnant women. Relaxin stimulated the production of cAMP in the 7th–8th week of gestation and at term but did not significantly alter the cervical cAMP levels in neither non-pregnant women nor in women in the 10th–12th week of pregnancy.

Previous studies have shown that porcine relaxin reduces collagen synthesis in tissue from the human cervix and lower uterine segment. The present observations indicate that these effects can be mediated by cAMP.
Sex hormone binding globulin response to testosterone. An androgen sensitivity test
Authors: Belgorosky A. , Rivarola M. A.
Published: December 2008

Abstract. Adequate distinction between an abnormality in androgen secretion or in target cell response is important in the diagnosis and management of male pseudohermaphroditism. Hormone serum levels give reasonable information on steroid secretion, but there are no simple methods, in clinical practice, to evaluate target cell response to androgens. In this work, we have evaluated the validity of the acute decrease in serum (SHBG) after administration of hCG or exogenous testosterone, as an indicator of androgen sensitivity in prepubertal subjects. The results were expressed as percentage of basal values. In control subjects, after hCG, SHBG dropped below 85% of basal, mean 55 ± 17, and, after exogenous testosterone, below 80%, mean 62.18 ± 8.85. In 23 patients studied with the hCG test, 10 positive and 13 negative results were found, but most of the negative responses became positive after exogenous testosterone. Of 25 patients studied with the exogenous testosterone test, 19 positive and 6 negative results were found. Clinical analysis of these 6 patients with negative responses showed that 4 subjects had a confirmed androgen insensitivity syndrome, while clinical information was compatible with this diagnosis in the other 2 patients. Furthermore, in 4 additional patients with the androgen insensitivity syndrome, but with high basal serum testosterone, this test was also negative. It is concluded that determination of serum SHBG after hCG is not reliable as an androgen sensitivity test, but the detection of the decrease in serum SHBG after exogenous testosterone is a useful and simple test of androgen sensitivity.
Naloxone administration does not affect gonadotrophin secretion in male patients with isolated hypogonadotrophic hypogonadism
Authors: Maggi Mario , De Feo Maria Laura , Mannelli Massimo , Delitala Giuseppe , Forti Gianni
Published: December 2008

Abstract. We evaluated the gonadotrophin response to acute naloxone administration (10 mg iv) in 4 male patients with isolated hypogonadotrophic hypogonadism (age range 18.5–26 years) before and after pituitary priming with daily infusions of GnRH (25 μg/h for 4 h) for 4 days.

A blunted gonadotrophin response to acute GnRH administration (100 μg iv) and a lack of response to naloxone was observed before pituitary priming. After repeated infusions of GnRH, pituitary gonadotrophin responsiveness to GnRH was restored, whilst naloxone still did not affect gonadotrophin levels.

Our data suggest that in male isolated hypogonadotrophic hypogonadism 1) the lack of pituitary response to naloxone is not due to pituitary hyporesponsiveness to GnRH; 2) endogenous opioids do not exert any inhibitory influence on GnRH secreting neurons and thus are not involved in the pathogenesis of this disease.
Nocturnal high-dose dexamethasone suppression test in the aetiological diagnosis of Cushing's syndrome
Authors: Bruno O. D. , Rossi Maria A. , Contreras Liliana N. , Gómez R. M. , Galparsoro G. , Cazado E. , Kral Martha , Leber Beatriz , Arias D.
Published: December 2008

Abstract. Seventeen patients with well-proven Cushing's syndrome (13 with Cushing's disease, 3 with adrenal tumour and 1 presenting ectopic ACTH syndrome caused by bronchial carcinoid) were investigated by using a single-dose 8 mg dexamethasone nocturnal test. The results obtained were compared with those of the classical 8 mg Liddle's test, metyrapone stimulation, plasma ACTH concentration and with the final diagnosis reached through surgery, pathologic anatomy, and/or clinical and biochemical follow-up of the patients after treatment. The diagnostic efficacy or the predictive power of the test (defined as the ratio between the number of cases in which the diagnosis was correctly predicted and the total number of cases), was at least 82.4% vs 84.6% for the classical 8 mg Liddle's test. This percentage increased to 94.1% when the results of repeated tests on three patients with conflicting data were included. It is concluded that the nocturnal high-dose dexamethasone suppression test is a valuable tool in the aetiological diagnosis of Cushing's syndrome.
Catch-up growth following transfer from three times weekly im to daily sc administration of hGH in GH deficient patients, monitored by knemometry
Authors: Hermanussen M. , Geiger-Benoit Karin , Sippell W. G.
Published: December 2008

Abstract. A novel and non-invasive technique of growth measurement is introduced. By this method the length of the human lower leg is measured with an accuracy of 0.1 mm. Thus, growth velocities can be estimated within a few weeks. In the present study the immediate changes of growth velocity are demonstrated, following the transfer of growth hormone administration from three times weekly im to daily sc in 9 growth hormone deficient children, age 7.4 to 20.5 years. The first observation period (3 times weekly im administration) ranged from 32 to 72 days, the second observation period (daily sc administration) ranged from 160 to 267 days). During the study, the total weekly dosage of growth hormone remained unchanged (12 IU/m2/week).

In all 9 patients growth velocity increased significantly after the transfer of application. Mean growth velocity of the lower leg rose from 0.04 mm/day up to 0.065 mm/day. Mean growth velocity of total body height rose form 4.8 cm/year up to 6.9 cm/year.

In addition, differential lower leg growth rates of 3 to 4 week periods were established in all 9 patients, revealing a significant catch-up growth spurt immediately following the transfer of application. During this spurt mean lower leg growth velocity rose form 0.04 mm/day up to 0.091 mm/day. This marked increase of lower leg growth rates lasted for only a few weeks and was followed by a period of decreased growth velocity. On the long run, growth velocity shifted upward in a wave-like pattern, stabilizing on a significantly higher level than before the transfer of application.
Higher plasma somatomedin A (biological) and C (immunological) levels with sc than with im growth hormone replacement therapy
Authors: Christiansen J. Sandahl , Kastrup K. W. , Alberti K. G. M. M. , Petersen K. E. , Christiansen C. , Ørskov H.
Published: December 2008

Abstract. In a short-term cross-over study the effect of daily sc human growth hormone was compared with that of thrice weekly im treatment. At the end of each 6-week treatment period the 10 growth hormone deficient children were admitted to hospital for evaluation of diurnal plasma levels of hormones and intermediary metabolites. Somatomedin A as well as C levels were higher in 9 of 10 children after sc than after im growth hormone therapy. This may be the basis for previous observations of improved growth after change to sc treatment.
The relationship between prolactin, dehydroepiandrosterone sulphate and testosterone in normally menstruating females
Authors: Wathen N. C. , Perry L. , Hodgkinson S. , Chard T.
Published: December 2008

Abstract. Circulating levels of prolactin, dehydroepiandrosterone sulphate (DHEAS) and testosterone (T) were measured in single blood samples from 115 normal women throughout the menstrual cycle. There was an inverse relationship between prolactin and both DHEAS and T. Subjects with high serum prolactin levels had significantly lower levels of DHEAS and T.
Prolactinoma of the pituitary containing amyloid
Authors: Paetau A. , Partanen S. , Mustajoki P. , Valtonen S. , Pelkonen R. , Wahlström T.
Published: December 2008

Abstract. A transsphenoidal operation was performed in a 27 year old man because of a large intrasellar expansion and marked hyperprolactinaemia (33 000 mU/l). The tumour found in the operation bulged into the sphenoidal sinus and was extirpated.

On histopathological examination the tumour consisted mainly of congophilic amyloid spherules with intermingled sparse adenoma cells. The adenoma cells were strongly positive for prolactin in immunoperoxidase staining, and in electron microscopy they contained secretory granules. Ultrastructurally the amyloid spherules consisted of masses of concentrical extracellular amyloid filament bundles.
Sequential changes in the pituitary thyroid axis after chronic TRH administration: effects on euthyroid and thyroxine treated female rats
Authors: Iglesias R. , Llobera M. , Montoya E.
Published: December 2008

Abstract. The effect of chronic oral thyrotrophin-releasing hormone (TRH) administration on thyrotrophin (TSH), l-triiodothyronine (T3) and l-thyroxine (T4) serum levels, pituitary TSH concentration and serum response to acute TRH injection, has been studied in female rats under different thyroidal conditions: shamoperated control animals, and thyroidectomized animals receiving 25 μg l-T4/100 g body weight/day. After 30 days, these groups were divided into two subgroups (6–10 animals per group), one receiving the aforementioned treatment and the other the same plus 2 mg TRH/10 ml distilled water (DW), as drinking water.

TRH-treated sham-operated animals showed significantly reduced serum and pituitary TSH levels and inceased serum T3 levels at most of the times studied (1, 6, 10, 18 and 34 days of oral TRH or DW administration), and a transient elevation in serum T4 between day 1 and 6. Thyroidectomized-l-T4-treated animals showed increased serum and pituitary TSH levels throughout the treatment and reduced T3 and T4 serum levels at the beginning, as compared to thyroidectomized-l-T4-treated animals.

TSH response to iv TRH administration on the 10th day of oral TRH administration was reduced in controls chronically treated with oral TRH as compared to nontreated controls, and was increased in thyroidectomizedl-T4-treated animals on chronic TRH vs the same group on oral DW.

These results suggest that chronic TRH administration can stimulate TRH synthesis in vivo, bypassing the inhibitory effects of thyroid hormones, the increased pituitary TSH reserve being responsible for the partial restoration of a response to acute TRH injection in the thyroidectomized-l-T4-treated animals.
Responses of patients with Bartter's syndrome to angiotensin III and angiotensin II-(3–8)-hexapeptide
Authors: Kono Tsuyoshi , Ikeda Fumitake , Taniguchi Ataru , Imura Hiroo , Oseko Fumimaro , Yoshioka Mieko , Khosla Mahesh C.
Published: December 2008

Abstract. Studies were conducted to determine whether or not angiotensin III [AIII] and angiotensin II-(3-8)-hexapeptide [ANG-(3–8)] have their own specific arteriolar binding sites different from angiotensin II [AII] binding site(s) in man. Four patients with Bartter's syndrome were given asn1-,val5-AII by iv infusion at rates of 10, 20, 50 and 100 pmol/kg · min, each for 7 min. One hour later AIII was infused iv in the same 4 patients at rates of 50, 100, 250 and 500 pmol/kg · min, each for 7 min. After 100 or 150 mg/day of indomethacin treatment for 7 days, the same All and AIII infusions were repeated. All patients showed blunted pressor responses to both All and AIII before indomethacin and the responses were improved after indomethacin. Moreover, increment curves of blood pressure for AII were almost identical with those for AIII in individual patients both before and after indomethacin. ANG-(3–8) was infused iv in 3 normal men and 3 of the 4 patients with Bartter's syndrome at a rate of 3.500 pmol (2.838 ng)/kg·min for 15 min. Blood pressure rose in the normal men (12/12 mmHg on the average) but did not rise in the patients. These results suggest that All, AIII and ANG-(3–8) have the same arteriolar binding sites in man.
Effects of FSH and LH on adenylate cyclase activity in rat granulosa cell membranes during follicular maturation
Authors: Nordenström K. , Rosberg S. , Roos P.
Published: December 2008

Abstract. Adenylate cyclase activity was measured in membranes prepared of granulosa cells isolated from PMSG-treated immature rats and the effects of ovine, highly purified human and rat gonadotrophins were compared. Furthermore, a comparison of the effects of the human preparations (hLH, hFSH) on the adenylate cyclase activity in membranes prepared from granulosa cells isolated at different stages of follicular maturation, was performed.

The adenylate cyclase in membranes of immature granulosa cells was stimulable with FSH but not with LH, while in pre-ovulatory granulosa cell membranes, both gonadotrophins were stimulatory with FSH generally being more effective than LH. Surprisingly, the dose-response curve for ovine LH (oLH) was biphasic with a plateau at a level of adenylate cyclase activity corresponding to the maximal stimulatory effect of hCG. With increasing oLH concentrations the response resumed and the maximal stimulation corresponded to that of oFSH. With highly purified rat gonadotrophins the FSH response was significantly higher than the response to LH at all concentrations tested. Using highly purified human gonadotrophins the maximal FSH response was 50% higher than the maximal LH response and by adding increasing concentrations of hFSH to a maximally stimulatory concentration of hLH it was possible to mimic the biphasic dose-response curve for oLH. When the membranes were prepared from ganulosa cells isolated after the pro-oestrus LH/FSH surge there was clear increase in the sensitivity of the adenylate cyclase to stimulation with LH although the maximal response was unaffected. The sensitivity to FSH was not altered.

These data indicate that FSH gives a higher maximal stimulation of the adenylate cyclase in rat granulosa cells than does LH, and the biphasic dose-response curve seen with oLH most probably is due to a FSH contamination in the LH preparation used. After in vivo exposure to the pro-oestrus LH/FSH surge no desensitization was observed but instead a clear increase in LH sensitivity. It thus seems as if the primary FSH sensitive cell under the influence of the LH/FSH surge turns to a primary LH sensitive one.
Correlation of oestriol levels in saliva, plasma and urine of pregnant women
Authors: Lechner W. , Marth Ch. , Daxenbichler G.
Published: December 2008

Abstract. Unconjugated and total oestriol (E3) have been determined in saliva (S) and plasma (P) by radioimmunoassay using a highly specific antiserum against E3. Total oestrogens (E = E1 + E2 + E3) in urine were analysed by the Kober-Ittrich method. No correlation (P> 0.05) was found between unconjugated E3 (S) and total E (U) as well as total E3 (S) and total E (U). Total E3 (S) and unconjugated E3 (P), total E3 (S) and total E3 (P) correlated weakly (P < 0.05 and > 0.01). The six remaining correlations were highly significant (P < 0.001 or < 0.0001).
Contribution of individual compartments of the genital tract to oestrogen and testosterone concentrations in ejaculates of the boar
Authors: Claus R. , Schopper D. , Hoang-Vu C.
Published: December 2008

Abstract. The investigation of steroids in compartments of the genital tract of boars revealed that in the tubular fluid a pattern apparently exists which is unique in this compartment. It is characterized by high concentrations of unconjugated testosterone (35 ng/ml) and even higher amounts of oestradiol-17β (42.6 ng/ml) whereas in other compartments oestrone is the predominant oestrogen. At least in the ejaculate half of the total amount of oestrogens is bound to sperms and it is concluded that sperms act as a carrier for oestrogens. The accessory sex glands contribute to ejaculate concentrations to a varying degree (unconjugated testosterone 55%, conjugated testosterone 20%, unconjugated oestrogens 22%, conjugated oestrogens 12%) as could mainly be demonstrated by vasectomy with and without administration of hCG. Increasing the frequencies of ejaculations (up to three times a day) shows that the steroid transfer into the ejaculate is a rapid process.
Immunodetection of bovine chorionic somatomammotrophin (bCS)
Authors: Verstegen J. , Fellmann D. , Beckers J. F.
Published: December 2008

Abstract. Bovine chorionic somatomammotrophin (bCS) was detected in the bovine placenta by using an immunoenzymatic procedure. This hormone appears mainly located in the binucleate cells of the foetal cotyledons and to a lesser extent in some localized superficial areas of the foetal and maternal epithelium. These areas may correspond to foetal binucleate cells migrating into the maternal caruncles.
Catechol oestrogen induced initiation of implantation in the delayed implanting rat
Authors: Kantor Betsy S. , Dey S. K. , Johnson D.C.
Published: December 2008

Abstract. In the rat oestrogen is essential for induction of implantation in a progesterone primed uterus. The ability of the catechol oestrogens, 4-hydroxy-oestradiol (4-OH-E2) and 2-hydroxy-oestradiol (2-OH-E2) to initiate the implantation process (blue reaction, indicative of increased endometrial capillary permeability at the location of the blastocyst) in hypophysectomized delayed implanting rats was compared to that of oestradiol-17β (E2). Delayed implantation was maintained by daily administration of 2 mg of progesterone. A single sc injection of 100 ng of E2 or 400 ng of 4-OH-E2 consistently initiated implantation in all animals. When delivered sc via osmotic minipumps at a constant release rate of 10 ng/μl/h, implantation of a full complement of embryos was obtained with E given for 6 or 24 h. This dose 4-OH-E2 was ineffective when administered for 24 h. However, 25 ng/μl/h for 24 h was effective. When the dose was increased to 50 mg/μl/h implantation was evident in the majority of animals exposed to the hormone for 6 or 8 h; all animals implanted when this dose was given for 24 h. In contrast, 2-OH-E2 given at 50 ng/μl/h for 24 h was totally ineffective. When the dose of the latter steroid was raised to 200 ng/μl/h implantation was achieved in half of the animals when exposure was 24 h. The results suggest that when administered systemically, 4-OH-E2 is less potent than E2, but more potent than 2-OH-E2, for initiating implantation. The lower potency of systemically administered catechol oestrogens probably results from their rapid metabolism and clearance for the circulation and target tissues.
Calcium metabolism in paravertebral ligamentous ossification
Authors: Takuwa Yoh , Matsumoto Toshio , Kurokawa Takahide , Iizuka Masashi , Hoshino Yuichi , Hata Keishi , Ogata Etsuro
Published: December 2008

Abstract. Twenty-eight patients with paravertebral ligamentous ossification (PVLO) and 11 control subjects were studied in an attempt to examine possible involvement of disturbances in mineral metabolism in the development of PVLO. No significant difference in baseline serum calcium and fasting urinary calcium excretion was found between patients with PVLO and controls. Patients with PVLO showed lower serum inorganic phosphate (Pi) and tubular reabsorptive capacity for Pi (TmP/GFR) than controls. Basal nephrogenous cyclic 3',5'-AMP (NcAMP) was elevated in some patients with PVLO. A significant inverse relationship was found between basal TmP/GFR and NcAMP in patients with PVLO (r = −0.50; P < 0.01). Compared with controls, patients with PVLO had significantly lower calciuric responses to an oral calcium load (P < 0.05), suggesting decreased intestinal calcium absorption. Furthermore, a significant inverse correlation was found between basal NcAMP and the calciuric response in patients with PVLO (r = −0.42; P < 0.05). Serum 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25(OH)2D) levels were not significantly different between the two groups. The size of ossified areas in paravertebral ligaments estimated from spinal radiograms inversely correlated with the calciuric response to the oral calcium load (r = −0.50; P < 0.01). These data demonstrate that the development of PVLO is associated with decreased intestinal calcium absorption in the face of normal serum 1,25(OH)2D level. Thus, together with previous observations showing a high incidence of PVLO in patients with hypoparathyroidism or familial hypophosphataemic rickets/osteo-malacia, the present results suggest that the defect in the action of 1,25(OH)2D may underlie the development of PVLO.
The distribution of immunoreactive corticotrophin-releasing factor in the human pituitary stalk
Authors: Coates P. J.
Published: December 2008

Abstract. An immunohistochemical investigation into the distribution, of immunoreactive corticotrophin-releasing factor (IR-CRF) in the adult human pituitary stalk was carried out. Histological sections of six pituitary stalks were stained by an indirect immunoperoxidase technique, using a specific primary antiserum raised against synthetic ovine CRF. It was shown that IR-CRF is present surrounding the coiled capillaries of certain gomitoli bodies. These structures form the primary capillary beds of the portal system of blood flow supplying the anterior lobe of the pituitary gland. An investigation was made into the characteristics of the cellular elements of gomitoli bodies, as little is known of these structures. Immunocytochemical methods for epithelial cells (anti-cytokeratin and anti-epithelial membrane antigen), endothelial cells (factor VIII related antigen), glial cells (glial fibrillary acid protein and S100 protein) and neuroendocrine cells (neuron specific enolase) were employed, but none were positive.
Circannual concentrations of melatonin, gonadotrophins, prolactin and gonadal steroids in males in a geographical area with a large annual variation in daylight
Authors: Martikainen Hannu , Tapanainen Juha , Vakkuri Olli , Leppäluoto Juhani , Huhtaniemi Ilpo
Published: December 2008

Abstract. This study was aimed at elucidating the possible effects of a large annual variation in photoperiodicity on the secretory activities of the pineal gland, pituitary and testes. Serum daytime melatonin, FSH, LH, prolactin (Prl), testosterone and oestradiol concentrations were determined monthly over a year in 24 healthy young adult men (except for melatonin which was analysed only in 11 subjects) in northern Finland, where the day length is 22 h in mid-summer and 3.5 h in midwinter.

Serum daytime melatonin levels showed two annual peak values, in December and May, and a nadir was observed in August. The absolute values of the other hormones measured did not show significant month to month variation over the observation period. When hormone levels were calculated as percentages of the individual annual means, several significant differences were found between monthly levels. The melatonin peak in May (133 ±20%, se, of the annual mean) was associated with significant increases in LH (110 ±4%) and FSH (107 ± 3%). Prl levels (115 ± 9%) reached a maximum in January. The nadirs of melatonin and the pituitary hormones measured were seen in August. Oestradiol showed the highest values in April-June, but no significant variation was found in serum testosterone levels. Positive correlations were observed between FSH and LH (r = 0.41, P <0.01), and Prl and LH (r = 0.26, P< 0.01), whereas Prl and testosterone (r = −0.17, P< 0.01) were inversely correlated.

This study indicates circannual rhythmicity of peripheral serum daytime melatonin, gonadotrophin, Prl and oestradiol levels, but this variation was not related to extremes in daylight and therefore seasonal factors other than light may regulate this circannual variation.
Serum reduces the TSH content in rat pituitary cells in culture
Authors: Spira O. , Halabi A. , Vlodavsky I. , Atzmon R. , Gross J. , Gordon A.
Published: December 2008

Abstract. Euthyroid rat pituitary cells were plated on a natural extracellular matrix (ECM) and cultured in either a medium supplemented with hormones and growth factors (SM) or in an unsupplemented medium (USM). Hormone supplementation resulted in a marked increase in the number of cells and in a less pronounced increase in the TSH content. Addition of 10% dehormonized serum (DHS) to the medium caused a further increase in the cell number as well as a significant elevation in the GH content but, surprisingly, it caused also a dramatic decrease in the TSH content. Time course experiments revealed that the serum doubled the rate of suppression of the TSH. DHS prepared from rat serum was as effective as that prepared from foetal calf serum and heat-inactivation of the serum did not change its suppressive effect on the production of TSH. This effect was confined to the serum fraction which was precipitable with 45% ammonium sulphate but did not bind to Con-A.

It is suggested that a high molecular weight protein fraction of serum reduces the number of thyrotrophs in the culture and/or decreases the rate of TSH production by these cells.
Increased peripheral venous somatostatin concentration and decreased glucagon response to arginine in patients with insulin dependent diabetes mellitus without residual B-cell function Increased plasma SRIF in IDDM
Authors: Skare S. , Dahl-Jørgensen K. , Hanssen K. F. , Norman N.
Published: December 2008

Abstract. The glucagon response to insulin hypoglycaemia is frequently reduced in patients with IDDM. In the present study arginine infusion, thought to act directly on the islet cells, was used to stimulate somatostatin (SRIF) and glucagon in IDDM without residual B-cell function.

Thirteen IDDM patients' were compared with 13 sex-and age matched normal controls following an arginine infusion. The plasma SRIF concentrations in the 'IDDM group' and normal controls increased from 24.2 ± 2.5 to 31.1 ± 3.9 pmol/l (P <0.01) and 19.7 ± 1.7 to 23.9 ± 3.4 pmol/l respectively after 10 min (P < 0.01). The plasma glucagon concentrations increased from 27 ± 4.7 to 176 ±23.1 pmol/l (P < 0.01) and 36 ± 5.0 to 302 ± 31.9 pmol/l (P <0.01) respectively after 20 min.

Thus, in long standing IDDM without residual B-cell function, increased plasma SRIF concentrations are found and the glucagon response to arginine is reduced. The last observation further explains why these patients are especially vulnerable to hypoglycaemia.
Identification of insulin-like growth factor-I and its receptors in the rat testis
Authors: Handelsman D. J. , Spaliviero J. A. , Scott C. D. , Baxter R. C.
Published: December 2008

Abstract. As part of a study of the testicular production and action of insulin-like growth factor-I (IGF-I), adult rat testes were extracted with acidified methanol, yielding an immunoreactive IGF-I fraction corresponding in size to human IGF-I. The mean IGF-I content (± sem) of testes weighing approximately 1.1 g was 51.5 ± 5.6 ng/testis, and was not due to serum contamination. After a 3-day fast testicular IGF-I decreased by 80%, whereas serum IGF-I levels declined by 90%. Testicular homogenates and isolated Leydig cells were shown to contain specific IGF-I receptors, Ka = 2 × 109 m−1, with 10% IGF-II cross-reactivity. The concentration of these receptors was 2 pmol binding sites per testis, or 3.3 fmol per 106 Leydig cells. However IGF-I at 250 ng/ml had no effect on basal or hCG-stimulated testosterone production by isolated Leydig cells, measured over 3 h. Although an effect of IGF-I over longer incubation periods cannot be excluded, it is also possible that testicular IGF-I has a mitogenic role, rather than acting on differentiated testicular functions.
Prolactin dynamics in patients with non-secreting tumours of the hypothalamic-pituitary region
Authors: Barbarino Antonino , De Marinis Laura , Mancini Antonio , Menini Edoardo , D'Amico Colomba , Passeri Marina , Sambo Paola , Anile Carmelo , Maira Giulio
Published: December 2008

Abstract. Twenty-four patients with non-secreting tumours of the hypothalamic-pituitary region, diagnosed by radiographic procedures and confirmed at surgery, were examined before and after the surgical treatment to establish a correlation between Prl responsiveness to dynamic tests and the location of pathological tissue. Three groups of patients were identified. In 10 patients with an intrasellar tumour (group I), Prl had a positive response to TRH, metoclopramide (MCP), and nomifensine (NOM), both pre- and postoperatively. In 4 patients with tumours located entirely in the hypothalamus (group II), Prl responded to TRH, but remained unresponsive to MCP and NOM. Only a partial normalization of the Prl responses was obtained after surgery. Finally, 10 patients had an intra- and extrasellar tumour (group III). In 8 of them Prl responded to TRH, but the increment was lesser than that observed in hypothalmic tumours. Prl did not respond to MCP and NOM. After surgery, Prl responsiveness reappeared in some patients (6 after TRH, 4 after MCP, 3 after NOM). In 2 patients with extensive pituitary damage, Prl did not respond to all dynamic tests pre- or postoperatively.

In conclusion, Prl dynamic tests are a reliable tool for studying the altered control of Prl secretion in these patients, since plasma Prl stems from only normal lactotropes surrounding the tumoural tissue. The location of the tumour has a key role in influencing the pattern of Prl response to direct and indirect dynamic tests.
Probable ACTH-secreting pituitary tumour in association with Addison's disease
Authors: Yanase Toshihiko , Sekiya Kensaku , Ando Masaaki , Nawata Hajime , Kato Ken-ichi , Ibayashi Hiroshi
Published: December 2008

Abstract. A 61 year old Japanese man with a diagnosis of Addison's disease was admitted to Kyushu University Hospital for further investigation of high ACTH levels and hyperpigmentation which 37.5 mg of cortisone acetate failed to alleviate. The basal level of plasma ACTH was 700—1000 pg/ml, and following 25—37.5 mg cortisone acetate or 1 mg dexamethasone the levels were 300—600 pg/ml. The general pigmentation showed little improvement with such medication. Radiographic studies revealed a double floor of the sella turcica and cisternal herniation. These observations suggested the existence of a pituitary ACTH-secreting tumour. Plasma ACTH showed a circadian rhythm ranging from 440 to 1570 pg/ml and it was not suppressed to a normal range by oral administration of dexamethasone, 8 mg/day or by continuous infusion of dexamethasone, 1.25 mg/h for 2 h. Plasma ACTH responses of 80% above basal level to lysine-vasopressin (LVP), and 12% above basal to synthetic ovine corticotrophin releasing factor (CRF) were observed. FK 33-824, a methionine-enkephaline analogue, suppressed plasma ACTH to 85% of basal level, while bromocriptine (CB-154) caused no significant change. These findings led to a diagnosis of pituitary ACTHsecreting adenoma (corticotropinoma) in association with Addison's disease. The persistent circadian rhythm of plasma ACTH suggested that this adenoma may not be completely free from regulation by the central nervous system. This case may be clinically significant for investigation of the pathogenesis of pituitary adenoma, particularly in Nelson's syndrome.
Analysis of linkage between HLA haplotype and susceptibility to Graves' disease in multiple-case Chinese families in Hong Kong
Authors: Hawkins B. R. , Ma J. T. C. , Lam K. S. L. , Wang C. C. L. , Yeung R. T. T.
Published: December 2008

Abstract. Data from 10 Chinese families in Hong Kong with multiple cases of thyrotoxic Graves' disease were analysed to determine whether genes predisposing to Graves' disease are linked to the HLA region. No evidence was obtained in favour of either dominant or recessive inheritance of HLA-linked susceptibility to Graves' disease. Six of 10 affected parent-offspring combinations had haplotypes containing HLA Bw46 which is more than would be expected from the antigen frequency of Bw46 in normal controls. It is concluded that HLA-associated genes play a role in determining disease susceptibility but that other factors are involved in determining disease expression.
Role of naloxone and opioid peptides on thyrotrophin, alpha subunit and beta thyrotrophin by dispersed rat pituitary cells
Authors: Cacicedo L. , Franco F. Sánchez
Published: December 2008

Abstract. This study was undertaken to determine the effect of opioid peptides and naloxone on the secretion of thyrotrophin (TSH), alpha subunit (α subunit) and beta thyrotrophin (TSH-β) from rat pituitary dispersed cells in primary culture. Naloxone (NAL) 10−5m was found to increase basal TSH, α subunit and TSH-β secretion. This effect of NAL was not blocked by human β-endorphin (βh-End) 10−7 m. Concurrent treatment with triiodothyronine (T3) 10−7 m significantly decreased NAL stimulated secretion of TSH and its subunits. Thyrotrophin releasing hormone (TRH) stimulation of secretion of TSH and its subunits was not further augmented by NAL. In contrast, 10−7 m of βh-End, methionine-enkephaline (Met-Enk) and D-ala2-met-enkephalinamide (DALA) had no effect on secretion of TSH and subunits. A time course study confirmed no change in TSH secretion following pre-treatment with βh-End at 4, 10, 24 and 48 h. These findings go against a direct action of βh-End, Met-Enk and DALA on TSH secretion. The response of TSH and its subunits to NAL and the lack of interaction with βh-End might be explained by the existence of different types of opiate receptors. Counteraction of this effect by T3 suggests other possible mechanisms.
Evidence that a 'memory' for glucose metabolism desensitizes A-cell responsiveness in the perfused pancreas of the rat
Authors: Grill V. , Rundfeldt M. , Efendić S.
Published: December 2008

Abstract. The effects of prior exposure to glucose or an inhibitor of glycolysis (iodoacetate) on A-cell sensitivity to glucose in the perfused pancreas of the rat was investigated. Inhibition of glucagon secretion by a high glucose concentration (22 mm) was attenuated and delayed when tested 20 min after a previous infusion with the same glucose concentration. Previously elevated glucose also delayed for 2 min a glucagon response to glucose omission whereas the total response was not significantly affected. During a 20 min perfusion with 1 mm iodoacetate, glucagon secretion increased and rates of secretion were further augmented after withdrawal of iodoacetate. When introduced 10 min after cessation of the iodoacetate pulse, 22 mm glucose failed to affect insulin or somatostatin release but, conversely, induced a profound decrease in glucagon secretion which was more marked than during control conditions.

Conclusions: A-cell sensitivity to glucose is diminished and enhanced by prior fuel abundance and deprivation, respectively. Such effects could be due to persisting changes in A-cell energy availability rather than to pertubations in insulin or somatostatin secretion.
Diurnal administration of human growth hormone-releasing factor does not modify sleep and sleep-related growth hormone secretion in normal young men
Authors: Garry Philippe , Roussel Bernard , Cohen Richard , Biot-Laporte Sylviane , Charfi Abdel Elm , Jouvet Michel , Sassolas Geneviève
Published: December 2008

Abstract. hGRF (iv 50 μg) was administered to 6 normal young adult males at 09.00 and 20.00 h on different days. Nocturnal GH secretion was monitored during polygraphic sleep recordings on both control nights and nights following hGRF administration. Sleep-related GH secretion and sleep parameters were not affected by diurnal hGRF administration.