bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term kinetics of LRH-induced LH-release in the long-term ovariectomized rat
Authors: Koiter T. R. , Pols-Valkhof N. , Schuiling G. A.
Published: December 2008

In a first series of experiments plasma concentrations of luteinizing hormone (LH) were measured at 10 min intervals during 2 h of constant rate infusion of luteinizing hormone-releasing hormone (LRH; 104 ng/ h) in phenobarbitone-anaesthetized long-term ovariectomized (OVX) rats, treated with oil or oestradiol-benzoate (OeB). From these data the mean LH secretion rates during the sampling intervals were calculated using a one-compartment model for the elimination of LH from the plasma. It was found in the OeB-primed OVX rats that during the initial 30–40 min of infusion the LH release is high but constant. Thereafter it shows a further increase. In the oil-treated OVX rats a similar biphasic LH release pattern was found, but in these animals it was preceded by an initial phase of very high LH release, lasting a few minutes.

In another series of experiments a second LRH infusion (again 104 ng/h) was given to OeB-primed OVX rats, starting 1.5 h after the discontinuation of a first LRH infusion lasting either 1, 3.5 or 20 h. The resulting secondary LH responses were smaller the longer the first infusion had lasted, but the LH secretion pattern was similar with all three time schedules and resembled the triphasic pattern observed during the first experiment in the oil-treated OVX rats, rather than the biphasic pattern of the OeB-primed OVX rats.

These results indicate that the LH response to LRH of OVX rats (either treated with OeB or oil), like that of the cyclic rats, exhibits a phase of constant LH release. It is generally assumed that during this period conditions, necessary for the subsequent further increase of the LH secretion, are generated. It is concluded that these conditions largely disappear during a 1.5 h non-stimulus period. It is also concluded that the short initial phase of very high LH secretion is due to recent exposure of the LH-secretory system to stimulatory amounts of LRH.
Long-lasting desensitizing effect of short-term LRH exposure on the pituitary responsiveness to LRH in the ovariectomized rat
Authors: Koiter T. R. , Pols-Valkhof N. , Schuiling G. A.
Published: December 2008

The influence of short-term exposure to LRH on the responsiveness to LRH and on the LH content of the pituitary gland was studied in the 2-weeks ovariectomized rat. Rats were infused with LRH at the rate of either 208 or 1040 ng/h from 12.00 h to 15.00 h on day 0, and injected with 3 μg of oestradiol-benzoate (OeB) or oil at 09.00 h on either day 1 or day 3. LH-responses were induced by a 21-h lasting infusion of LRH at the rate of 104 ng/h, starting at 12.00 h on the day after the OeB/oil treatment. Control rats received only one LRH treatment: they were injected with OeB or oil on day—1 and LH-responses were induced on day 0.

Results were evaluated on the basis of two parameters: total amounts of LH released during exposure to LRH (1) and release efficiency, i.e. total amounts of LH released in relation to pituitary LH content (2). The findings obtained indicate that exposure to relatively low LRH concentrations causes a greater loss of release efficiency than exposure to relatively high ones. Loss of release efficiency may even increase long after the blood has been cleared of the releasing hormone. From the present experiments it can thus be inferred that exposure of the pituitary gland to LRH leads to either a marked loss of release efficiency and a relatively small LH depletion (1), or a smaller loss of release efficiency and a relatively large LH depletion (2). The two variables both influence the state of responsiveness of the pituitary gland and the present results indicate that only in situation 2 the LH-responsiveness recovers effectively. However, when after exposure to LRH rats are treated with OeB, the consequences, in terms of total amounts of LH released, of differences in degrees of loss of release efficiency and in depletion of LH are eliminated. It is suggested that during the ovulatory cycle this effect of oestrogen plays an important role in the process of recovery of the pituitary gland from diminished responsiveness to LRH induced by LRH.
Activation and clearance of a hormonogen, triglycyl-oxytocin, in the conscious dog
Authors: Stevenson Ralph W. , Robinson Iain C. A. F. , Parsons John A.
Published: December 2008

Triglycyl-oxytocin (TGOT) and oxytocin (OT) were administered iv and sc to conscious dogs and the plasma concentrations of these peptides determined simultaneously by RIA and bioassay. Constant iv infusions (1 h) at 23 pmol/kg/min produced plateau levels of 1.1 and 1.6 pmol/ml plasma for OT and TGOT respectively. Whilst the distribution space was similar for each peptide, TGOT persisted longer in the circulation (t½, for TGOT 6.6 min; for OT 4.2 min). Bioactive values for OT followed RIA values whether this peptide was given iv or sc. Although very little bioactivity was generated by iv infusions of TGOT, considerable amounts of bioactive OT were found in plasma after injection of TGOT subcutaneously. The hormonogen proved relatively resistant to oxytocinase, an enzyme that destroys OT rapidly. Our results indicate that TGOT is converted to OT in vivo and that its action as a hormonogen is more pronounced after sc than iv administration.
Oxytocin determination by radioimmunoassay in cattle
Authors: Schams D. , Baumann G. , Leidl W.
Published: December 2008

Oxytocin concentration in jugular vein blood was measured radioimmunologically with a detection limit of 3 pg/ml plasma in male and female cattle.

Five bulls were tested; during mating a cow in oestrus with intromission and ejaculation, during mounting a dummy or another bull with ejaculation into an artificial vagina or during false mounts. No increase in oxytocin concentrations could be observed, but stimulation with an electro-ejaculator caused an increase ranging from 5–84 pg/ml after a latent period of 3–5 min. A similar response was observed in two cows following the same procedure.

The contact with a bull, false mount or mating with intromission and ejaculation was not followed by a measurable oxytocin release in 5 test cows.

The following stimulation techniques, massage of vulva and clitoris, massage of cervix and uterus per rectum, artificial insemination, introduction of a speculum into the vagina or insufflation of air into the vagina were performed with 5 cows and 5 heifers.

Insufflation of air into the vagina was the most effective stimulus, eleciting an oxytocin release up to 588 pg/ml. All 5 heifers responded positively, as well as 4 cows in oestrus. The other manipulations caused an oxytocin response mainly in heifers (whether in oestrus or dioestrus), whereas only one cow in oestrus responded with an oxytocin release. In general, oxytocin concentrations increase about 30–90 s after the start of the stimulus.
Temporal and seasonal relationships between LH, testosterone and antlers in fawn and adult male roe deer
Authors: Sempéré A. J. , Lacroix A.
Published: December 2008

Plasma LH and testosterone patterns, testis and antler growth and rutting period were determined in the roe deer from birth to 4 years of age. In adults, a typical annual cycle was observed for these endocrine growth and behaviour events. The greatest testosterone levels (9.65 ng/ml) and testis size (13.13 cm3) were recorded for an average period of one month, from July 15th to August 15th, and coincided with the rutting period. At this time antler size was maximal (from 12.70 to 21.35 cm according to age). Plasma testosterone levels and testis size decreased rapidly from September until December (0.23 ng/ml and 3.48 cm3, respectively) and casting occurred at the same time as the decrease of testosterone. It was concluded that testosterone release is an important factor which is correlated with testis growth, antler maintenance and rutting behaviour. Plasma LH levels showed large fluctuations throughout the year and an annual cycle was demonstrated. The lowest plasma LH concentrations were recorded in December (1.36 ng/ml) while higher values were recorded in February (3.25 ng/ml). This suggests that an increase of pituitary gonadotrophic activity appears in spring and is responsible for the testicular reactivation. In the roe deer as in other seasonally breeding species it may be inferred that gonadotrophic activity is controlled by daylength. The present findings show that sexual activity is initiated by increasing daylength and that the roe buck is the only cervidae whose breeding period is early summer.

In fawns, a low plasma testosterone level (1.27 ng/ml), a small testis size (2.96 cm3) and antler growth ('buttons') were observed a few months after birth in autumn and high plasma LH levels (4.08 ng/ml) were recorded before this, as early as the first month of age. It is suggested that interrelationships between LH, testosterone, testis and antler growth begin to appear at this time and that the precocious LH release induces the first pubertal testicular activity. This first increase of gonadotrophic activity which appears in summer can not be related to the photoperiod as in adults and would be under central endogenous control for the onset of the pubertal maturation process. From this pubertal state (3 months of age) to the following testicular initiation where potential sexual maturity is probably reached (7-9 months of age), complex temporal interrelationships occur between daylength, gonadotrophic and testicular factors.
Δ5-androstenediol: kinetics of metabolism and binding to plasma proteins in normal post-menopausal women
Authors: Bird Charles E. , Tremblay John , Masters Valerie , Clark Albert F.
Published: December 2008

Δ5-androstenediol (Δ5-diol) while having minimal androgenic activity is of potential biological importance because it binds to oestrogen receptors and has oestrogenic activity in several systems. We have examined Δ5-diol metabolism in post-menopausal women utilizing the constant infusion technique. The metabolic clearance rate for 11 subjects was 763 ± 50 1/24 h or 467 ± 30 1/m2/24 h. Labelled dehydroepiandrosterone, testosterone, Δ4-androstenedione, androsterone and the sulphates of Δ5-diol, dehydroepiandrosterone and androsterone were found in the plasma. Of all the kinetic parameters only the conversion ratio for dehydroepiandrosterone sulphate was different from that for young women (4.958 ± 0.410 for young women vs 3.084 ± 0.220 for older women). The plasma concentration of Δ5-diol was 0.94 ± 0.19 ng/ml and the calculated blood production rate was 686 ± 80 μg/24 h. The per cent free plasma Δ5-diol was 4.6 ± 0.25. These values are slightly lower but not significantly different from those previously reported for normal young women.
Plasma levels of medroxyprogesterone acetate (MPA), sex-hormone binding globulin, gonadal steroids, gonadotrophins and prolactin in women during long-term use of depo-MPA (Depo-Provera®) as a contraceptive agent
Authors: Jeppsson Sten , Gershagen Sten , Johansson Elof D. B. , Rannevik Gunnar
Published: December 2008

The aim of the study was to evaluate the functional state of the hypothalamo-pituitary-gonadal axis and to assess the concentrations of MPA in the peripheral blood during very long-term use of depomedroxyprogesterone acetate (DMPA) as a contraceptive agent.

The concentrations of MPA, sex-hormone binding globulin (SHBG) and the different pituitary and gonadal hormones in the peripheral blood were measured in nine 26–41 year old women. They had for 4.4–10.6 years (mean 8.9 years) been receiving DMPA im in a dose of 150 mg every 12th week as a contraceptive. Blood samples were obtained immediately before an injection of DMPA, 2 weeks later, and again immediately before the next injection. SHBG was measured by radio-electroimmunoassay; MPA, gonadal and pituitary hormones by RIA.

The investigation showed that the oestradiol levels — even after very long-term use of DMPA — were still within the normal range for the early follicular phase. Gonadotrophins and prolactin were within the normal range for eumenorrhoeic women as well as the concentration of SHBG. MPA did not accumulate in the plasma. The changes in the plasma levels of oestradiol, MPA and SHBG after each injection disappeared within 12 weeks. The study appears to warrant the conclusion that even up to 10 years' use of DMPA in a dose of 150mg im every 12th week as a contraceptive agent, does not induce hormonal changes different from those seen after the very first injection.
Thyrotrophin and prolactin responses to thyrotrophin-releasing hormone in patients with Parkinson's disease
Authors: Martinez-Campos Abraham , Giovannini Paolo , Novelli Antonello , Cocchi Daniela , Caraceni Tommaso , Müller Eugenio E.
Published: December 2008

The thyrotrophin (TSH) and prolactin (Prl)-releasing effects of TSH-releasing hormone (TRH) were investigated in 20 subjects with Parkinson's disease (PD), unmedicated, on chronic treatment with a combination levodopa-benserazide (Madopar) or levodopa-carbidopa (Sinemet) or withdrawn from therapy. Administration of TRH (200 μg iv) induced in unmedicated patients TSH and Prl responses significantly lower than those of sex-and age-matched controls. In patients on Madopar therapy the TSH and Prl responses to TRH were greater than in unmedicated patients and comparable to those of controls, while in patients on Sinemet therapy the pituitary responses were undistinguishable from those of unmedicated subjects. Withdrawal of Madopar therapy resulted in a marked diminution of the TSH response but did not affect the Prl response to TRH. Withdrawal of Sinemet therapy did not alter the TSH and Prl responses to TRH. Concomitant evaluation of growth hormone (GH) levels, in none of the subjects evidenced non-specific changes in plasma GH following TRH.

Since TSH and Prl responses to TRH are inhibited by an enhancement of the dopaminergic tone, it would appear that the latter is preserved in the tuberoinfundibular system of unmedicated subjects and subjects on chronic Sinemet therapy, but is defective in subjects on chronic Madopar therapy.
ACTH-producing pituitary adenomas in Addison's disease: two cases treated by transsphenoidal microsurgery
Authors: Krautli Barbara , Müller J. , Landolt A. M. , von Schulthess F.
Published: December 2008

In 2 women with known Addison's disease, progressive hyperpigmentation reappeared years after an initial remission under conventional substitution therapy with cortisone. Excessively elevated plasma ACTH concentrations and radiological evidence of sella turcica deformation led to the diagnosis of ACTH-producing adenomas and prompted their removal by transsphenoidal microsurgery.

In one patient, a large Crooke's cell adenoma with extensive extrasellar expansion had caused severe and irreversible bilateral defects of the visual fields and unilateral optic atrophy. Surgical removal of the tumour and radiotherapy brought about a permanent disappearance of the hyperpigmentation, but eventually led to secondary hypothyroidism. In the second patient, the selective removal of a small intrasellar eosinophilic adenoma consisting of ACTH-producing cells did not alleviate the hyperpigmentation and did not lower the plasma ACTH concentration. However, hyperpigmentation regressed markedly within a year of treatment with a higher dose of cortisone.

The rarity of similar cases in the literature seems to indicate that insufficient feedback suppression of ACTH-producing cells in treated Addison's disease does not by itself induce the development of a pituitary adenoma, but might promote the growth of an independently and coincidentally occurring microadenoma, which would have caused Cushing's disease in a person with intact adrenal glands.
A case of ectopic ACTH syndrome: diagnostic difficulties caused by intermittent hormone secretion
Authors: Thorner Michael O. , Martin William H. , Ragan Gary E. , MacLeod Robert M. , Feldman Philip S. , Bruni Carlo , Williamson Brian R. J. , Orth David N.
Published: December 2008

A patient with a thymic carcinoid tumour causing ectopic ACTH syndrome is presented. The case illustrates the rapid development of the clinical and laboratory findings often associated with ectopic secretion of ACTH, including severe proximal myopathy, emotional lability, and hypokalaemic alkalosis. Interpretation of conventional tests of pituitary-adrenal function was complicated by intermittent secretion of ACTH by the tumour. The results of selective venous sampling for ACTH ruled out pituitary ACTH hypersecretion and were suggestive of a thymic source; computerized tomography of the chest localized the tumour. In vivo and in vitro investigations confirmed excessive ACTH production by the tumour, and surgical resection plus radiotherapy has resulted in resolution of the syndrome.

The diagnostic problems created by intermittent secretion of ACTH by these tumours and the pre-operative and post-operative medical management of these patients are discussed.
Testosterone, luteinizing hormone (LH) and follicle stimulating hormone (FSH) in plasma of rabbit from birth to adulthood. Correlation with sexual and behavioural development
Authors: Berger M. , Jean-Faucher Ch. , de Turckheim M. , Veyssiere G. , Blanc M. R. , Poirier J. C. , Jean Cl.
Published: December 2008

Plasma testosterone, LH and FSH levels were determined and correlated with reproductive organs growth, testicular differentiation, fighting and mounting behaviour in maturing rabbit.

An infantile phase of development extends from birth to 40 days, characterized by low testosterone and FSH levels, decreasing LH levels (until 20 days) and by a slow growth of testis and seminal vesicle. The peripubertal phase starts abruptly around day 40. It is marked by simultaneous events: the appearance of mature Leydig cells in the testis, a striking increase in testosterone and FSH levels, a small rise in LH levels and an acceleration of testicular growth. The phase of rapid growth of seminal vesicle and the first meiotic divisions start around day 70, in presence of high circulating levels of FSH and testosterone. Fighting (3 months) and mounting behaviour (146 ± 13 days) occur lately after a long period of high circulating testosterone levels.
Mineralocorticoid escape in man: role of renal prostaglandins
Authors: Dürr J. , Favre L. , Gaillard R. , Riondel A. M. , Vallotton M. B.
Published: December 2008

The role of renal prostaglandins (PGE2 and PGF2α) and kallikrein in the renal escape from excess mineralocorticoid has been evaluated in 10 normal volunteers on a high sodium diet. Escape from 9-α-fluorohydrocortisone (9-α-FF) administered for 12 days (0.6 mg daily) occurred within 4–5 days when 345 ± 50 mmol sodium had accumulated. Indomethacin, a cyclooxygenase inhibitor, was then administered for 3 days while maintaining 9-α-FF. This was followed by a further cumulative gain of 105 ± 28 mmol sodium after which escape resumed. Potassium balance remained negative throughout the study. Both PGE2 and PGF2α excretion increased significantly under 9-α-FF from respective control values of 220 ± 50 and 818 ± 86 ng/24 h, to 610 ± 317 and 1213 ± 132 ng/24 h at the time of escape. Concomitantly urinary kallikrein increased from 1.1 ± 0.2 to 2.5 ± 0.3 units/24 h. Creatinine clearance increased from a mean baseline value of 111 ± 4 to 123 ± 4 ml/min during the same period. Indomethacin produced an inhibition of prostaglandin excretion without significant alteration of kallikrein excretion. Overall these results and particularly the transient sodium retention induced by indomethacin at the time of mineralocorticoid escape, suggest that prostaglandins may contribute to the escape phenomenon, whereas the role of kallikrein does not appear to be determinant.
Alterations in serum thyroid hormones in euthyroid children with circulating anti-thyroid antibodies
Authors: Villalpando Salvador , Cisneros Ignacia , García-Bulnes Guadalupe , Urquieta Bárbara , Mondragón Lourdes , Junco Elisa , Parra Adalberto
Published: December 2008

Anti-thyroid antibodies are frequently found in otherwise normal populations (4.5–25.8%); however, there is scanty information about thyroid function status in affected individuals. In this report, the serum concentrations of TSH, T3, T4, rT3 and TBG and the titre of anti-thyroglobulin and anti-microsomal antibodies (haemagglutination technique) were studied in 520 healthy school children (260 boys and 260 girls) aged 6.0–17.9 years. Titres equal or greater than 1:16 of one or both antibodies were detected in 58 boys and in 77 girls (in 33 boys and in 24 girls with, and in 25 boys and 43 girls without, associated abnormalities in the serum concentrations of one or several hormones). The age distribution of thyroid antibodies followed a trimodal pattern with peaks at 7, 11 and 16–17 years in both sexes. The most striking finding was an abnormally elevated T3 concentration in 22 boys and 5 girls with positive antibodies, with no symptoms of thyroid dysfunction and with no clear relationship with simultaneous abnormalities in TSH, T4 or rT3; however, in 5 boys the TBG serum levels were increased. Serum from these patients was incubated with [125I]T3 before free radioactivity was precipitated with dextran-coated charcoal and the aliquots were analyzed by paper electrophoresis. Serum samples with high T3 levels bound significantly more radioactivity than normal or T3-free serum (P < 0.001) and an abnormal peak of radioactivity was present in the gamma globulin fraction, in the former but not in the latter two types of sera. The presence of high serum T3 levels in the absence of clinical symptoms of hyperthyroidism was probably due to sequestration of T3 by the anti-thyroglobulin antibody, which may have cross-reactivity with T3 and T4, as has previously been demonstrated both in animals and humans.
Thyrotrophin-releasing hormone responsiveness and degradation in children with chronic renal failure: effect of time of evolution
Authors: Henneberg C. Marti , Domenech J. M. , Montoya E.
Published: December 2008

In order to study the hypothalamic-pituitarythyroid function in children with chronic renal failure (CRF), the serum levels of l-thyroxine (l-T4), l-triiodothyronine (l-T3), reverse T3 (rT3), thyrotrophin (TSH) and prolactin (Prl) were measured by radioimmunoassay (RIA). Values were compared with those of normal subjects. Low levels of l-T4 were present in CRF patients as compared to controls. l-T3 was also found to be low but less than l-T4, and rT3 was lower in patients with long evolution. No alterations were observed in TSH basal levels, whereas Prl values in patients were high.

After thyrotrophin-releasing hormone (TRH) administration, TSH and Prl rose to similar levels in both groups, but high values were maintained throughout (120 min) in CRF. A significant negative correlation was found between the peak rise of the TSH response and the CRF evolution time. The l-T3 response to TRH administration (120 min) was similar in both CRF and controls.

The rate of in vivo and in vitro exogenous TRH degradation was decreased in patients with CRF or by their sera, respectively. Our data seem to confirm that the hypothyroid syndrome described in CRF patients is of hypothalamic origin, and the low in vivo and in vitro TRH degradation rates are a consequence of this state.
The aging Leydig cell V. Diurnal rhythms in aged men
Authors: Murono E. P. , Nankin H. R. , Lin T. , Osterman J.
Published: December 2008

Basal circulating levels of progesterone, 17α-OH-progesterone, dehydroepiandrosterone, androstenedione, testosterone and oestradiol-17β were measured in 'young' (median age 34 years) and 'old' (median age 73 years) normal males between 08.30 and 17.00 h. Diurnal rhythms for 17α-OH-progesterone, dehydroepiandrosterone, androstenedione and testosterone were observed in both young and old men. No rhythms were discernable for progesterone or oestradiol-17β in both age groups.
Progestin receptors in prolactin and growth hormone producing tumours in rats
Authors: Naess Oddvar , Haug Egil , Attramadal Arne , Gautvik Kaare M.
Published: December 2008

Progesterone and corticosterone have a similar effect on the production of growth hormone (GH) and prolactin (Prl) by pituitary tumour cells (GH3 cells) in culture. Previously we have shown that progesterone has a high affinity for the glucocorticoid receptors in these cells. Progesterone may therefore exert its effects through binding to the glucocorticoid receptor. The aim of the present study was to investigate if the GH3 tumour cells and an oestrogen induced pituitary tumour, which also produce GH and Prl, possess specific receptors for progesterone. Both the GH3 tumours and the oestrogen induced pituitary tumour were in fact found to possess cytoplasmatic receptor molecules for progesterone by using the potent progestin R5020 as a marker. Isoelectric focusing revealed one binding component (pH 5.9), which was of protein nature. The binding was of high affinity (Kd 2 × 10−9 mol/l). In the oestrogen induced tumour, the maximal binding was 70 fmol/mg cytosol protein. In female rats with GH3 tumours the binding was 55 fmol/mg cytosol protein. Priming of the animals with 1 mg oestradiol-valerate increased the binding to 116 fmol/mg cytosol protein, whereas very little binding was found in GH3 tumours from rats castrated 7 days before sacrifice. The receptors in the oestrogen induced pituitary tumour and the GH3 tumours exhibited high affinity for R5020 and progesterone, whereas corticosterone had no significant affinity for the receptors. Using exchange assay, it was demonstrated that the cytoplasmic progestin receptors could be translocated to the nucleus after administration of progesterone to the animals. Thus, the presence of specific progesterone receptors, different from the glucocorticoid receptors, strongly indicates that the effects of progesterone on GH and Prl production are mediated through the progesterone receptors.
Experimental conditions leading to a low degree of thyroglobulin iodination without loss in coupling efficiency
Authors: Kohler H. , Studer H. , Gerber H. , von Grünigen C.
Published: December 2008

The hormone content of in vitro iodinated thyroglobulin is a constant fraction of the iodine content of the protein under most, but not all, experimental conditions. In contrast, in vivo iodinated human thyroglobulin may contain as little as 10% or as much as 50% of its total iodine in the T4 molecules. Surprisingly, in some poorly iodinated thyroglobulins up to 30% of the iodine may be found in T4. The mechanism of the apparent dissociation between iodination and coupling efficiency (i.e. percentage of total iodine present as iodothyronines) may be dilution of pre-existing high iodinated thyroglobulin stores by non-iodinated prethyroglobulin. This hypothesis was tested by feeding rats PTU and KClO4 for 9 days and injecting T4 during the last 2 days. Thyroglobulin iodination dropped from 0.9 to 0.13% but the coupling efficiency remained unchanged at 25.7 and 23.9%.

The exchange of highly iodinated thyroglobulin molecules for non-iodinated ones is one of the two in vivo mechanisms suggested so far which can lead to an apparent dissociation of thyroglobulin iodination and couling efficiency.
The effect of cyproterone acetate on pituitary-ovarian function and clinical symptoms in hirsute women
Authors: Lunell Nils-Olov , Zador Göran , Carlström Kjell , Eneroth Peter , Patek Eva , Wager Jan
Published: December 2008

Ten hirsute women in fertile age were given 50 mg cyproterone acetate (CA) on day 5–14 and 50 μg ethinyl oestradiol (EE2) on day 5–21 except during the first treatment cycle when EE2 was given on day 15–21. The treatment lasted for 12 months. Clinical examination and hormone analysis were undertaken every third month. LRH tests were performed prior to treatment with CA in late follicular phase and after one week of administration of the drug. Subjective improvement of hypertrichosis was reported in 7 women, objectively a significant decrease in hair scores was observed. Shortterm effects of CA alone included significantly decreased serum levels of oestrogens while FSH, LH, 4-androstene-3,17-dione and testosterone remained unaffected. Longterm administration of CA and EE2 resulted in significantly decreased serum levels of FSH, LH and oestrogens whereas 4-androstene-3,17-dione and testosterone were not affected. The gonadotrophin response to LRH did not reveal any significant difference before and after treatment. 4-Androstene-3,17-dione and testosterone did not change during the LRH tests but increased levels of oestrogens were observed at the end of the test during the CA treatment.

Since CA alone causes decreased oestrogen levels without any suppression of the basal gonadotrohin levels, it is speculated that CA directly affects the ovarian steroid biosynthesis. On the other hand the adrenal androgens seem to be unaffected by the drug.
Alteration of free hCG subunits secretions in ectopic pregnancy
Authors: L'Hermite-Balériaux M. , Van Exter C. , Deville J. L. , Gaspard U. , Hechtermans R.
Published: December 2008

Intact hCG and free α and β hCG subunits were simultaneously measured by specific radioimmunoassays in blood samples from pregnant women with normal pregnancy (n = 87; control group) or with a ruptured ectopic pregnancy (n = 35) between 5 and 14 weeks. Since the lower 95% confidence limit of the hCG levels encountered in normal pregnancies was at 1200 ng/ml, the pathological group has been subdivided in 2 subgroups: A (n = 17) if hCG was greater and B (n = 18) if hCG was lower than this limit.

In subgroup A, mean hCG and β hCG were significantly lower than in the control group in contrast to a tendency to secrete and/or release more α hCG, as reflected by a significantly increased ratio of α hCG/hCG. Thus, the ectopically implanted trophoblast, even when able to produce normal amounts of hCG, undergoes an impairment of its ability to synthesize and/or release free β hCG but not free α hCG, of which the synthesis and/or release appears to become even enhanced.

In subgroup B, mean hCG, α hCG and β hCG levels were all dramatically suppressed but there was surprisingly less alteration of the synthesis and/or release of free β hCG.

These alterations of the relative secretions of the free hCG subunits, compared to those occurring for various glycoproteic hormones in pathological circumstances, reflect probably early alterations of the trophoblast.
Hypothalamic and pituitary cytosol receptors to 5α-dihydrotestosterone and oestradiol-17β during the prepubertal period in the male lamb
Authors: Pelletier J.
Published: December 2008

Hypothalamic and pituitary cytosol receptors to 5α-dihydrotestosterone (DHT) and oestradiol-17β (E2) were measured in the male lamb from 9 to 120 days of age, 24 h after castration. Concentrations of pituitary receptors did not change with age, but the total number of receptors and the pituitary weight showed a parallel increase (P < 0.001). Conversely, there were no marked changes in the total number of hypothalamic receptors but this number was high as early as 9 days of age, 42.4 and 80.0 fmol/hypothalamus for DHT and E2, respectively. These data suggest that the number of hypothalamic and pituitary cytosol receptors to DHT and E2, is not a critical parameter in the succession of events which precedes puberty.
Plasma insulin and C-peptide in relation to glucose intolerance in middle-aged men
Authors: Malmquist Jörgen , Lindgärde Folke , Eriksson Karl-Fredrik , Johansson Elisabet
Published: December 2008

The relation between glucose homeostasis and insulin secretion (immunoreactive insulin and C-peptide) was studied in middle-aged males matched for age and body weight. Subjects with mild type II diabetes mellitus were compared to normals and to individuals with impaired glucose tolerance (IGT). In addition, the diabetics were subdivided according to duration, some of the subjects having recently deteriorated from IGT status.

In the IGT individuals, there were no indications of a reduction in basal or glucose-induced insulin output. On the contrary, data indicate somewhat higher than normal secretion. Within the type II diabetics, those of short duration were largely similar to normals, whereas diabetes of longer duration was associated with some diminution in indices of B cell secretion.

The data support the notion that a deficient insulin output is not a primary pathophysiological event in the development of type II diabetes.
Pattern of plasma progesterone, oestradiol-17β, luteinizing hormone and androgen in non-pregnant buffalo (Bubalus bubalis)
Authors: Arora R. C. , Pandey R. S.
Published: December 2008

Domestic buffaloes were used to characterize the pattern of progesterone, oestradiol-17β, LH and androgen in the systemic circulation following infertile insemination. Concentrations of hormones were measured by RIA in blood samples collected daily or at alternate days following insemination. The concentration of progesterone was lowest on the day of insemination, and increased significantly to a peak level of 4.00 ± 0.60 ng/ml by day 13 post insemination. After day 17, it declined significantly (P < 0.01) to reach low levels by day 21. The concentration of oestradiol-17β was high at the time of insemination and declined significantly (P < 0.01) by day 2 after insemination. It was maintained around the basal level till day 18 with minor peaks in between this period. It again rose significantly (P < 0.01) at subsequent oestrus. The mean level of LH was highest at the time of insemination, and declined significantly (P < 0.01) by day 1 post insemination. It did not vary appreciably till the animal returned to oestrus. The oestrous value of LH and progesterone were negatively correlated (r = −0.77). The androgen level was observed to be high at insemination in 3 out of 5 animals, but the overall pattern of this steroid was inconsistent during the period studied. A high concentration of androgen was recorded in all the animals from day 2–5 before the onset of oestrus.
Spontaneous development of hyperprolactinaemia
Authors: Rjosk Hanns-Kristian , Fahlbusch Rudolf , Werder Klaus von
Published: December 2008

Spontaneous development of hyperprolactinaemia was investigated by measuring prolactin levels in 34 hyperprolactinaemic females with a normal sella turcica, in 19 females with a radiologically proven prolactinoma, and in 19 females with a histologically proven prolactinoma after transsphenoidal surgery. Prolactin levels remained unchanged or declined in 69 patients followed over a period of up to 6 years. In one patient with a normal sella turcica, prolactin levels increased accompanied by the development of a radiologically detectable microprolactinoma. In one patient with a radiologically proven macroprolactinoma the increase of human prolactin (hPrl) levels was accompanied by infiltrative and parasellar prolactinoma growth. One patient showed a dramatic increase of post-operative persisting elevated hPrl levels without radiological changes. These findings suggest that prolactinomas in general have a limited growth potential which should be considered in the management of hyperprolactinaemic patients.
Influence of pregnancies on prolactinomas
Authors: Rjosk Hanns-Kristian , Fahlbusch Rudolf , von Werder Klaus
Published: December 2008

Hyperprolactinaemic patients desiring pregnancy with a normal sella turcica or radiological evidence for a microprolactinoma without suprasellar extension were treated with bromocriptine. Females desiring pregnancy with large adenomas or suprasellar extension were treated by transsphenoidal surgery and in most instances post-operatively with bromocriptine. This differentiated management allowed the outcome of 65 pregnancies with delivery at term without complications related to the sella turcica.

Considerable variations of prolactin levels during pregnancy suggesting different oestrogen sensitivity of the prolactinoma cells were encountered. However, a rapid fall of the prolactin levels in 60 patients after termination of pregnancy indicated that oestrogen stimulation does not cause persisting growth of the adenoma. In contrast, in 10% of pregnancies of hyperprolactinaemic patients a reduction of the prolactin levels has been observed leading to spontaneous ovulatory cycles in 5 patients.
Effect of anorexia nervosa on gonadotrophin secretion in a patient with gonadal dysgenesis
Authors: Kauli Rivka , Gurewitz Rachel , Galazer Avinoam , Prager-Lewin Ruth , Gil-Ad Irit , Laron Zvi
Published: December 2008

The 11th documented concurrence of anorexia nervosa (AN) and XO-gonadal dysgenesis (GD) is reported. This is the first endocrine study of such a disease combination. The patient, a 15-year-old girl, has been followed since early childhood and comprehensive endocrinological investigations were performed before, during and after the episode of AN. The dynamic changes in the thyroid and pituitary hormones were in concordance with those already observed by us as well as by others in patients with AN. The most remarkable observation concerned the gonadotrophin secretion: during the anorectic episode basal levels and peak responses to LRH of both LH and FSH were seen to decrease from the hypergonadotrophic range to the normal prepubertal range whereas after recovery from AN and regain of weight these rose back to castration levels. AN would seem to be the only condition yet known able to abolish temporarily the hypergonadotrophic state of GD, a fact favouring the hypothesis that AN is associated with a reversible hypothalamic dysfunction. It is assumed that this disturbance is due to nutritional as well as to psychological factors. The significance of the coexistence of AN and GD is discussed and it is suggested that psychological factors in GD may be implicated in this association.
The presence of a high concentration of thyroxine in thyroid epithelial cells
Authors: Kawada Jun , Nishida Mikio , Yoshimura Yoshiyuki , Yamamoto Tomoko
Published: December 2008

Swine thyroid epithelial cells were isolated and the intracellular concentration of thyroxine was measured by radioimmunoassay and high pressure liquid chromatography.

The estimated concentrations of intracellular thyroxine were 1.89 × 10−8 μg/cell by radioimmunoassay, and 0.708 × 10−8 μg/cell by high pressure liquid chromatography, which were equivalent to 4.39 × 10−5 m and 1.78 × 10−5 m, respectively. These levels were about a thousand-fold higher than that in the circulation (3.18 ± 0.59 μg/dl, 3.98 × 10−8 m).
Parathyroid hormone bioassay using human kidney cortical cells in primary culture
Authors: Zonefrati Roberto , Brandi Maria Luisa , Rotella Carlo M. , Selli Cesare , Toccafondi Roberto
Published: December 2008

The biological activity of parathyroid hormone (PTH) has been investigated by measuring intracellular accumulation of cyclic AMP (cAMP) in human kidney cortical cultures. Enzyme dispersed cortical cells from non-invaded kidney poles of patients undergoing nephrectomy for cancer were used after 5 days of primary culture. Bovine PTH (1–84) produced a significant increase of cAMP accumulation in cultured cells at a dose (53.7 ng/ml) 10-fold lower than that found for the minimal stimulatory effect when using preparations of human purified plasma membranes. The action of bovine PTH (1–84) was very rapid, a response was detected after 5 min and a ceiling effect after 30 min. Cortical cells showed a slightly lower sensitivity to synthetic bovine PTH (1–34) (half maximal increase dose: 0.66 μg/ml), compared to bovine PTH (1–84) (half maximal increase dose: 0.32 μg/ml), but revealed a higher sensitivity to human PTH purified from the medium of parathyroid cell cultures (half maximal increase dose: 11.2 ng/ml). Arginine-vasopressin (AVP) also increased the cAMP accumulation of kidney cortical cultured cells, with a potency and efficacy lower than that of human 'culture' PTH, while in kidney medullary cells in primary culture AVP exerted a strong response and the effect of PTH was poor or absent. Calcitonin and glucagon were weak stimulators of kidney cortical cell cAMP accumulation.
Oestrogen and progesterone receptors in the involuting rat uterus
Authors: Geyer H. , de Gregorio G. , Lernbecher G.
Published: December 2008

The concentrations of cytoplasmic oestrogen and progesterone receptors were measured in rat myometrium during the post partum involution of the uterus. The concentration of the oestrogen receptor declined within 24 h post partum to about 20% of the value at delivery. A slight rise in the concentration occurred during the subsequent 24 h. The concentration of the progesterone receptor remained nearly constant the first day after delivery. Thereafter it decreased just as the concentration of the oestrogen receptor had fallen one day before.

The results suggest that the post partum levels of oestrogen and progesterone receptors are regulated by the same mechanisms as those known for the non-pregnant state.
Effects of the antioestrogen tamoxifen on steroid induced morphological and biochemical changes in the castrated dog prostate
Authors: Funke P.-J. , Tunn U. W. , Senge Th. , Neumann F.
Published: December 2008

The effect of the antioestrogen tamoxifen (TA) was investigated in different types of steroid-induced benign prostatic hyperplasia (BPH) in the castrated dog by histological, histochemical and biochemical analysis. A 6 months treatment with oestradiol-17β (E2) alone resulted in cystic and stromal hyperplasia and squamous epithelial metaplasia with a striking prostatic weight increase. DNA and RNA content of the total glands increased significantly. The histochemical results and zinc values indicated the loss of normal epithelial function due to metaplatic transformation. The E2 induced cystic and metaplastic hyperplasia was prevented by TA while the stromal proliferation was significantly decreased but not abolished. Biochemical determinations revealed an effect similar to castration. After combined treatment with E2 and 3α-androstanediol (3α-diol) TA completely suppressed squamous metaplasia. A 3α-diol induced glandular proliferation, monitored by a positive histochemical reaction, and significantly elevated zinc, DNA and RNA contents prevailed. A partial stromal stimulation indicates stimulating effects of 3α-diol too on the stroma. The antioestrogenic effects of tamoxifen on experimentally induced BPH mainly manifest at the E2 induced epithelial alterations. The abolishing effects at the stromal level are distinct but not so impressive.
Specific interaction of radioactive anti-androgen TSAA-291 with androgen receptor in rat prostates
Authors: Sudo Katsuichiro , Yoshida Keiji , Nakayama Ryo
Published: December 2008

A steroidal anti-androgen TSSA-291 (16β-ethyl-17β-hydroxy-4-oestren-3-one) bound to a macromolecular component in the cytosol of rat ventral prostates with high affinity (Kd = 5.0 × 10−9 m) and in a saturable manner. The number of binding sites was comparable to that for 5α-dihydrotestosterone (5α-DHT). [3H]TSAA-291 binding was effectively displaced by unlabelled 5α-DHT, 19-nortestosterone and cyproterone acetate but to a lesser degree by corticosterone. Glycerol density-gradient centrifugation analysis revealed that the sedimentation coefficeint of the [3H]-TSAA-291-macromolecule complex was 3–4.5 S. However, when the unlabelled cytosol was fractionated by glycerol density-gradient centrifugation before the binding of [3H]TSAA-291 was examined, specific binding of [3H]TSAA-291 was observed in fractions corresponding to 8–10 S. Binding of the [3H]TSAA-291-macromolecules complex to prostatic nuclei and DNA-cellulose was considerably less than binding by the [3H]5α-DHT-macromolecule complex. Instability of the TSAA-291 binding component on heat treatment before and after complex formation was also revealed and the results are discussed in terms of the anti-androgenic activity of TSAA-291.
Restoration of oestrogen-positive feedback effect on LH release in women with prolactinoma by transsphenoidal surgery
Authors: Koike Koji , Aono Toshihiro , Tsutsumi Hirohisa , Miyake Akira , Kurachi Keiichi
Published: December 2008

The effect of hyperprolactinaemia on the hypothalamo-pituitary axis was assessed by iv injection of 100 μg luteinizing hormone releasing hormone (LRH) in 7 women with prolactinoma before and 3 months after normalization of the Prl level by transsphenoidal surgery. A dose of 20 mg of conjugated oestrogen (Premarin®) was also injected iv into patients with prolactinoma before and 4 months after surgery, and the serum LH levels were determined serially for 120 h after the injection. Surgical treatment caused significant reduction of the mean (± se) serum prolactin (Prl) level from 123.3 ± 7.8 to 19.4 ± 5.6 ng/ml. But the differences in the basal levels of LH (11.3 ± 2.2 to 8.6 ± 1.5 mIU/ml), FSH (8.3 ± 2.4 to 10.6 ± 3.7 mIU/ml) and oestradiol (26.6 ± 8.6 to 37.5 ± 5.5 pg/ml) before and 4 months after surgery were not significant. An exaggerated LH response to LRH in untreated prolactinoma patients was also observed after surgical treatment. After surgical treatment, patients showed LH release with a peak between 48 and 72 h after the injection of Premarin, whereas before treatment they did not show any LH discharge. The mean percent increase in LH between 48 and 72 h was also significantly higher after operation than before operation. These results suggest that the hyperprolactinaemia in prolactinoma patients may cause an impaired positive feedback effect of oestrogen on LH release and that this derangement can be reversed by reduction of the Prl level by adenomectomy.
Studies on the mechanism by which ACTH stimulates renin activity and angiotensin II formation in man
Authors: Oelkers Wolfgang , Köhler Angelika , Belkien Lutz , Fuchs-Hammoser Regina , Maiga Mahamane , Scherer Burkhart , Weber Peter C.
Published: December 2008

Ten IU of ACTH (1–24) per day was infused for 34 h (starting at 7 a.m.) into 8 normal men on a constant diet containing 135 mm Na+ per day. All subjects retained between 152 and 181 mm of sodium. Potassium balance was negative. Plasma renin activity (PRA) and plasmaangiotensin II (P-A II) started to rise in most subjects after 6 to 8 h of infusion, reached a maximum after 24 h and then tended to decline. As shown previously, the rise in PRA is not due to a rise in plasma renin substrate concentration. Systolic, but not diastolic blood pressure increased significantly on the second day of ACTH-infusion. Plasma cortisol (P-F) was continuously stimulated by ACTH. Plasma aldosterone (P-aldo) increased rapidly 1 h after ACTH administration, then tended to fall, and increased again in most subjects, roughly in parallel with PRA. No significant changes in electrolyte balance, PRA, P-A II, P-F and P-aldo occurred in 3 subjects receiving 'sham'-infusions. Additional experiments in subjects treated with propranolol or indomethacin allowed the conclusion that the effect of ACTH on PRA and P-A II is not mediated by renal beta-adrenergic receptors, but perhaps (partially?) by prostaglandins. Since the infusion rate of ACTH was not much higher than the secretion rate of ACTH in the early morning hours, it is possible that ACTH is physiologically involved in the regulation of renin secretion.