bluuebunny/crossref_metadata_2025 huggingface dataset:
HOMOLOGOUS RADIOIMMUNOASSAY OF THYROTROPHIN IN RAT PLASMA
Authors: David Kieffer J. , Weintraub Bruce D. , Baigelman Walter , Leeman Susan , Maloof Farahe
Published: December 2008

An homologous radioimmunoassay (RIA) using the highly purified rat thyrotrophin (TSH) and anti-rat TSH recently made available by NIAMDD is described in detail.

Evidence that the assay measures TSH and only TSH includes the following:

Treatment of rats with TSH-releasing hormone (TRH) caused a significant increase (averaging 12-fold) and treatment with T4, a significant decrease (averaging 4.5-fold), in plasma TSH.

Points for TSH standards and those for dilutions of plasma from TRH-treated rats fell on the same line, and regression lines calculated separately for standards and dilutions of plasma did not depart significantly from parallelism.

At 14 days after gonadectomy of male rats, a time when plasma LH and FSH levels are known to be high, the assay showed no increase in plasma TSH. Moreover, reduction of plasma TSH levels by T4 was as great in gonadectomized rats as in controls.

Assay of rat LH, rat FSH and rat prolactin, in 7 concentrations each, showed that cross-reaction averaged less than 1 % in all cases. Other workers have calculated values greater than 1 % for TSH contamination of rat LH and FSH. The slopes of regression lines for the 3 hormones tested for cross-reaction did not differ significantly from the slope for TSH standards. This result strengthens the hypothesis that the apparent slight cross-reactions are due to TSH contamination.

Findings for T4-treated rats and saline-treated controls show that the homologous RIA is more sensitive than previous, heterologous assays: In previous studies, plasma TSH levels of most or all of rats treated with T4 were not clearly greater than zero. By contrast, in the homologous RIA reported here, values for such rats did not overlap the range of the zero point on the one hand, nor the range for saline-treated controls on the other. Thus, distinct ranges were defined for both normal and low TSH levels. In view of the 1:20 final dilution of plasma during assay, it does not seem likely that non-specific effects of plasma were primarily responsible for the low TSH values of T4-treated rats.

Additionally, the useful range of the homologous assay (about 200-fold) is greater than that of earlier assays (about 70-fold, or less). Finally, the use of highly purified rat TSH for standards has avoided inconsistencies previously encountered with bovine TSH standards.
METABOLISM OF PREGNENOLONE AND PREGNENOLONE SULPHATE IN HUMAN FOETAL LIVER TISSUE IN VITRO
Authors: Huhtaniemi Ilpo
Published: December 2008

The metabolism of pregnenolone and pregnenolone sulphate was studied in incubations with minced foetal liver tissue. In most of the incubations, non-radioactive substrates were used, and the identification and quantitative determination of the metabolites formed was carried out by gasliquid chromatography and gas chromatography – mass spectrometry. Both the free and sulphated substrates were extensively metabolized by the liver preparations, and with both substrates, the same enzyme activities were observed. Furthermore, active sulphate conjugation was seen with free pregnenolone. No sulphatase activity was observed, and the direct conversion of pregnenolone sulphate to 16α-hydroxypregnenolone sulphate was demonstrated in incubations with [7-3H]pregnenolone [35S]sulphate. The highest conversion rate with both substrates, about 25 %, was for 16α-hydroxylation. Other enzyme activities detected were 20α-reduction and 3β-hydroxy-5,16-pregnadien-20-one formation. In sulphate conjugation and 16α-hydroxylation a slight decrease was observed with advancing foetal age, while in the case of 20α-reduction, somewhat higher conversion rates were observed in older foetuses. In this respect, the only significant difference between the two substrates used was the more pronounced decrease in pregnenolone sulphate 16α-hydroxylation with increasing foetal age.

This study sheds more light on the biological significance of steroid sulphates as metabolic intermediates in the human foetus and further evidence for their direct conversion into other steroid sulphates was obtained. It is suggested that the foetal liver plays an active role in such conversions.
CELLULAR AND SUBCELLULAR LOCALIZATION OF 3H-OESTRADIOL IN THE OVIDUCT AND UTERUS OF THE NEONATAL RAT
Authors: Sheridan Peter J. , Sar Madhabananda , Stumpf Walter E.
Published: December 2008

Two day old female rats were injected sc with 1.0 μg of 3H-oestradiol per 100 g body weight and killed 2 h later. Oviducts and uteri were removed, mounted on tissue holders, and frozen in liquefied propane. Four μm frozen sections were cut in a cryostat and mounted according to the dry-mount and thaw-mount autoradiographic procedures. The sections were exposed at –15°C for different periods of time, then photographically processed and stained with methyl green-pyronin. Radioactivity was found concentrated in nuclei of cells of the luminal epithelium in the uterus, but not in the oviduct, while cells of the connective tissue and muscularis showed nuclear concentration of radioactivity in both organs. Pretreatment with oestradiol inhibited the nuclear concentration of radioactivity, whereas pretreatment with 5α-dihydrotestosterone had no effect. It is concluded that both the uterus and oviduct of the neonatal rat have receptors for oestrogen as early as 2 days after birth.
BIOSYNTHESIS OF 3β,17β-DIHYDROXYANDROST-5-EN-16-ONE BY HEPATIC MICROSOMES FROM PREVIABLE AND ANENCEPHALIC HUMAN FOETUSES
Authors: Tabei Toru , Heinrichs W. LeRoy
Published: December 2008

Hepatic microsomes from previable and anencephalic human foetuses incubated with 14C-dehydroepiandrosterone synthesize 16-keto-A5-diol in addition to 6 other metabolites. The rate of production of 16-keto-A5-diol (nmoles min−1mg−1) was greater than those to 16α-OH-DHA or A5-triol. Other products accounting for most of the remaining radioactivity were A5-diol, 7α- and 7β-OH-DHA, and 7-keto-DHA. Rates of 7α-hydroxylation were lower in liver from the anencephalic foetuses than from previable foetuses, but no qualitative differences appeared. These data demonstrate the capacity in vitro of human foetal liver for synthesizing 16-keto-A5-diol, an abundant steroid of umbilical cord blood and the physiologic precursor for 16-keto-oestradiol-17β, a major urinary oestrogen of human pregnancy.
THYROID PROTEINS AND HORMONE SYNTHESIS IN HUMAN THYROID CANCER
Authors: Thomas-Morvan Colette , Nataf Berthe , Tubiana Maurice
Published: December 2008

Thyroid iodoproteins and hormone synthesis have been studied in vivo and in organ culture in 44 cases of thyroid cancer. In a few cases, Tg1) (17–19 S) is virtually absent; a portion of the light fractions (3–8 S), which seems to represent some precursors of Tg, incorporated in culture the 14C-amino acids.

In most of the cases, the solubility profiles, sedimentation patterns as well as electrophoretic migration of proteins were normal. The content of Tg and the concentration of stable iodine (127I) in Tg are less than that of "normal" tissues, and the deficiency in iodination appears to be more pronounced than the depression of the Tg synthesis. Most frequently the radioiodine uptake is very low and most of the iodine remains in the gland as iodide and MIT. In those tissues which organify radioiodine, it is incorporated into tyrosine molecules and is metabolized to the stage of iodothyronines (T4 + T3); there must then be little or no defect in coupling reactions. There is a linear relation between the concentration of stable iodine in Tg and the level of hormone synthesis, as we have found in "normal" gland and benign thyroid diseases. These results suggest that the overall disorder seen in thyroid cancer tissues appears to involve one of the initial steps of hormone synthesis. The very low mean iodination of Tg in these tissues suggests a great heterogeneity in the functional activity throughout the tumour.

TSH has a very variable effect on thyroid cancer tissues maintained in organ culture: in 46 % of the cases the hormone has no effect. In some instances TSH may significantly increase the incorporation of radioiodine into soluble iodoproteins, Tg as well as the albumin fraction.
NEONATAL IMPRINTING OF ENZYME LEVELS IN RAT ADRENALS
Authors: Goldman Allen S. , Gustafsson Jan-Åke , Stenberg Åke
Published: December 2008

The metabolism of [4-14C]4-androstene-3,17-dione was studied in adrenals from adult male and female rats gonadectomized at birth, at 14 and 43 days of age. A control group consisted of adult male and female rats sham-operated at birth. Another group consisted of adult male and female rats castrated at birth and treated with a single dose of testosterone propionate 24 h after the operation. The 5α-reductase activity was found to be higher in female than in male sham-operated rats (P < 0.02); postpubertal castration led to an increased enzyme activity in both male and female rats. Neonatal testectomy led to higher 5α-reductase activity than testectomy at 14 days of age (P < 0.05) and treatment with testosterone propionate at birth tended to lower the 5α-reductase activity. These results indicate that during the neonatal period testicular androgens irreversibly "imprint" or "programme" the adrenal 5α-reductase activity to a lower, masculine level. Also the 11β-hydroxylase system was found to be subject to androgenic inhibition in two ways: 1. by irreversible "imprinting" or "programming" neonatally and 2. by reversible suppression in adult life. It is concluded that the neonatal masculinization process effectuated by testicular androgens and previously shown to affect hypothalamic functions and liver enzyme levels also affects the activities of steroid metabolizing enzymes in adrenal tissue with possible effects on the adrenal secretion of steroid hormones.
"STEROID-CELL" ANTIBODY IN ENDOCRINE DISEASES
Authors: Kamp Peter , Platz Per , Nerup Jørn
Published: December 2008

By means of an indirect immunofluorescence technique, sera from 116 patients with Addison's disease, an equal number of age and sex matched controls and 97 patients with other endocrine diseases were examined for the occurrence of antibody to steroid-producing cells in ovary, testis and adrenal cortex.

Fluorescent staining was observed in the theca cells of growing follicles, the theca lutein cells, testicular Leydig cells and adrenal cortical cells, i. e. cells which contain enzyme systems used in steroid hormone production. The "steroid-cell" antibody was present in 24 % of the patients with idiopathic Addison's disease, equally frequent in males and females, and in 17 % of the patients with tuberculous Addison's disease, but was rarely found in controls, including patients with other endocrine diseases.

Female hypergonadotrophic hypogonadism made an exception, since the "steroid-cell" antibody was found in about half the cases with this condition.
A RADIOIMMUNOASSAY OF UNCONJUGATED OESTRADIOL IN URINE
Authors: Kono Shinzo , Loriaux D. Lynn , Lipsett Mortimer B.
Published: December 2008

A radioimmunoassay has been developed for the measurement of unconjugated oestradiol in urine. After extracting with ether and purifying by thin layer chromatography, the assay is performed using anti-serum prepared against oestrone-17-oxime-bovine serum albumin conjugate. Dextran-coated charcoal is used to separate free and bound fractions. The measurable range on the standard curve is from 10 to 1000 pg. The blank of the method is 9.7 ± 3.6 pg (sd) and is independent of urine volume. The intra-assay coefficient of variation is 9.5 % and the inter-assay variation is 12.8%. The accuracy and specificity of the method are also satisfactory. During one menstrual cycle, urinary free oestradiol averaged 32 ng/day (n = 9, range 22 to 58) during the follicular phase; 341 ng/day at the mid-cycle peak; and 46 ng/day (n=10, range 12 to 138) during the luteal phase. The oestradiol content of 3 consecutive 24-h urines from a normal man was 4.8 ng/day (2.7 to 7.2).
UNSUCCESSFUL TREATMENT OF ACROMEGALY WITH MEDROXYPROGESTERONE ACETATE
Authors: Atkinson Richard L. , Dimond Richard C. , Howard W. James , Earll Jerry M.
Published: December 2008

Six patients with active acromegaly were treated with medroxyprogesterone acetate (MPA) in a dose of 10 mg four times a day for periods of two weeks to six months. Basal growth hormone (GH) levels, oral glucose tolerance tests, insulin tolerance tests, and arginine stimulation tests were obtained before and after one week, one month, three months, and six months of therapy. There were no significant changes in mean basal GH levels or in patterns of GH secretion following administration of glucose, insulin and arginine. Impairment in carbohydrate tolerance was observed in five of six patients during at least one evaluation period. MPA did not produce any therapeutic benefit in our patients with acromegaly and may have contributed to deterioration of the clinical condition.
THE EFFECT OF EPINEPHRINE ON THYROID HORMONE SYNTHESIS IN THE RAT
Authors: Joasoo A. , Murray I. P. C.
Published: December 2008

The effect of epinephrine (100 μg/100 g body weight) on the distribution of 131I among the iodo-amino acids in the rat thyroid was studied. Chromatography of thyroid homogenates was carried out, using as solvent n-butanol:ethanol:2 n ammonia (5:1:2). Epinephrine resulted in elevation of the ratio of monoiodotyrosine (MIT) to diiodotyrosine (DIT), and decreased the incorporation of 131I into iodothyronines. The ratio of triiodothyronine (T3) to thyroxine (T4) was unchanged. Epinephrine did not influence the rate or extent of protein-binding of iodine, determined both by precipitation with trichloroacetic acid and by chromatography. The nature of the iodoprotein formed was studied by its solubility characteristics in phosphate buffer. No change was observed with epinephrine. The changes caused in the MIT/DIT ratio by epinephrine could be completely prevented by the administration of excess iodide, while the incorporation of iodide into T4 improved, but remained slightly below normal. It is postulated that the changes caused by epinephrine in 131I distribution occurred as a result of decreased iodination of thyroglobulin, but an additional effect on iodothyronine synthesis cannot be excluded.
REVERSAL BY INSULIN TREATMENT OF ABNORMAL GROWTH HORMONE PATTERN IN NEWLY DIAGNOSED DIABETES MELLITUS
Authors: Corrall R. J. , Hunter W. M. , Campbell I. W. , Harrower A. D. B. , Duncan L. J. P. , Clarke B. F.
Published: December 2008

The effect of insulin therapy on growth hormone secretion was studied in five newly diagnosed young insulin-dependent diabetic men. All showed a markedly abnormal pattern of secretion immediately prior to insulin therapy and following "normalization" of the blood glucose there was a significant fall in plasma growth hormone levels after a period of one to two months though these were still considerably elevated above the normal control range.

These findings lend support to the view that the abnormal growth hormone secretion observed in diabetes may be the consequence rather than the cause of the disordered carbohydrate metabolism.
ANTAGONISTIC EFFECTS OF DINITROPHENOL AND CYANIDE ON HEPATIC THYROXINE DEIODINATION
Authors: Hillier A. P.
Published: December 2008

Dinitrophenol inhibits the deiodination of thyroxine by the isolated perfused rat liver; the effect is reversible. Subsequent addition of cyanide to the perfusion fluid opposes the inhibitory effect of dinitrophenol and restores the deiodination rate to normal. However, addition of cyanide alone has little effect. Similar results are obtained with triiodothyronine.
PROGESTERONE IN THE UTERUS
Authors: Egert D. , Jonat W. , Maass H.
Published: December 2008

Uterine segments of normal rats were incubated with [1,2-3H] progesterone in TC Medium Eagle HeLa for 20 min, 1, 2 and 3 h. Only one compound containing up to 98 % of the total extracted radioactivity was found in the extract of uterine segments and in the nutrient media at all the times studied. This compound was identified by analytical TLC, chemical reactions and crystallization to constant activity as progesterone. In vitro metabolism could not be observed under the applied conditions (10−7m) over a 3 h period, no radio-metabolites were detected in either the uterine segments or in the nutrient fluids.
PROGESTERONE IN THE UTERUS
Authors: Egert D. , Maass H.
Published: December 2008

Radio-metabolites of progesterone and progesterone itself were found in the uteri of intact pregnant rats 20 min after injection of [1,2-3H]progesterone. However, after evisceration and removal of the foeto-placental unit, and following injection of the labelled steroid, the progesterone content in the extract from the pregnant rat uterus markedly increased while the metabolite levels correspondingly decreased. An analogous change was observed in the plasma. Thus it appears probable that progesterone is not metabolized in the uterus of pregnant rats, and that metabolites found in this tissue originate predominantly in the foetoplacental system and appear in the plasma and extracellular fluid present in the uterine tissue.
URINARY STEROID DYNAMICS AFTER A SINGLE DOSE OF METYRAPONE
Authors: Zachmann M. , Völlmin J. A. , Zagalak M.
Published: December 2008

A single oral dose of metyrapone (500 mg/m2) was given to 4 healthy adult males and their steroid excretion was determined in individual urine samples by gas chromatography on a glass capillary column. THS increased markedly and reached a mean peak value of 576 μg/h 6.2 h after ingestion. THE decreased from 327 to 163 μg/h within the first 4 h. Pregnanetriol increased only slightly, while pregnanediol, pregnenetriol and the individual 17-ketosteroids remained unchanged. The same metyrapone dose was then administered to 77 children and adults with and without endocrine disease. In 43 of them, 24 h urines were collected after ingestion of the drug and the mean THS-response was 1833 ± 237 μg/m2/24 h (sem, n = 32) in endocrinologically normal and only 75 ± 34 μg/m2/24 h (n = 6) in ACTH-deficient subjects. There was a positive correlation (r = 0.67) between the basal THE- and post-metyrapone THS excretion. In 34 subjects, 12 h urine samples were obtained after metyrapone. In this group, the mean THS-response was 1078 ± 268 μg/m2/12 h (n = 7) in the endocrinologically normal and 84 ± 23 μg/m2/12 h in the ACTH-deficient subjects (n = 11). In the remaining 16 patients with endocrine disease, but without other evidence of ACTH-deficiency, the results varied. In some they were normal and in others they were pathological inspite of a normal plasma-11-hydroxycorticoid response to insulin induced hypoglycaemia. The latter result was found in primary hypothyroidism and in some cases with growth hormone deficiency or hypoglycaemia. This test appears to provide a simpler and more sensitive evaluation of the hypothalamus-pituitary-adrenal axis and is especially suitable for use in children.
EVALUATION OF THYROID STATUS WITH THE "EFFECTIVE THYROXINE RATIO" (E. T. R.®)
Authors: Kølendorf Klaus , Siersbæk-Nielsen Kaj , Hansen Jens Mølholm , Friis Thorkild
Published: December 2008

A new in vitro thyroid function test, "Effective Thyroxine Ratio" (ETR®) has been tested in 170 patients, and the ETR values in patients with normal and abnormal thyroid function have been compared to the concentration of absolute free thyroxine and free thyroxine index in serum. Among 42 hyperthyroid patients tested with ETR, 13 had values within normal range (30.9 per cent). Three of 18 hypothyroid patients had normal values (16.8 per cent). Eighty-nine per cent of 27 pregnant women and all of 17 patients treated with genuine oestrogens had ETR values within normal range. A high positive correlation was found between values of ETR, absolute free thyroxine in serum (r = 0.62) and free thyroxine index (r = 0.83).
REMISSION OF FAMILIAL GOITROUS HYPOTHYROIDISM
Authors: Gray Henry W. , Thomson John A. , Kennedy J. Stuart
Published: December 2008

Three male siblings with familial goitrous hypothyroidism due to a defect of thyroidal iodide organification have been studied. Withdrawal of thyroxine therapy from 2 of the brothers led to a rapid return of clinical hypothyroidism in one but the other brother remained euthyroid for approximately 3 years off his thyroxine therapy despite continuing evidence of defective iodide organification in his thyroid. The phenomenon is contrasted with that produced by massive administration of thyroid hormones ("Stoss therapy"), but no satisfactory explanation for its occurrence can be given.
REGULATION OF THE ACTIVITIES OF THE ENZYMES INVOLVED IN THE METABOLISM OF STEROID HORMONES IN RAT LIVER: THE EFFECT OF 19-NORTESTOSTERONE AND THE INFLUENCE OF CYPROTERONE ACETATE ON THE ACTION OF TESTOSTERONE AND 5α-DIHYDROTESTOSTERONE
Authors: Ghraf Rüdiger , Lax Edmund Rodney , Hoff Hanns-Georg , Schriefers Herbert
Published: December 2008

The androgens testosterone and 5α-dihydrotestosterone, the anabolic drug 19-nortestosterone and the anti-androgen cyproterone acetate were investigated with regard to their modifying action on the sexual differentiation of the activities of rat liver enzymes involved in steroid hormone metabolism.

The activities of the enzymes (Δ4-5α-hydrogenase, 20-ketoreductase, 3α-and 3β-hydroxysteroid dehydrogenase, NAD- and NADP-dependent Δ4-3β-hydroxysteroid dehydrogenase, total steroid hydroxylases, 7α- and 16α-hydroxylase) were determined in cell-free liver fractions of male animals castrated on day 25 of life and killed on day 90; and of castrated animals which, from day 75 to 89 received daily sc injections (0.3 mg/100 g body weight) of the anabolic drug or the androgen only or in combination with cyproterone acetate (3 mg/100 g body weight). With the exception of 7α-hydroxylase castration leads to a feminization of the enzyme activity pattern. However, the degree of feminization varies from enzyme to enzyme.

The administration of testosterone or of 5α-dihydrotestosterone reverses the effect of castration. With 5α-dihydrotestosterone activity values were reached which in some cases were significantly higher than those obtained with testosterone. Although both androgens restored the enzyme activities to the normal male values, neither androgen was able to compensate for the weight loss of the seminal vesicles in the dose administered. The administration of 19-nortestosterone in the same dose as testosterone is only 30 % as effective in restoring the weight loss of the seminal vesicles, but leads to identical activities of Δ4-5α-hydrogenase and of hydroxysteroid dehydrogenases as are found for testosterone. 19-Nortestosterone is without influence on the activities of total steroid hydroxylases and of 16α-hydroxylase.

16α-Hydroxylase is the only enzyme in which the activity enhancing effects of testosterone or of 5α-dihydrotestosterone can be completely blocked by the simultaneous administration of the anti-androgen cyproterone acetate.

In all other enzyme activities the anti-androgen does not interfere with the effect of the androgens although it blocks their action on the weight restitution of the seminal vesicles by 60–70 %.

7α-Hydroxylase does not exhibit any androgen dependency. Neither castration nor the subsequent administration of the two androgens, or of the anabolic drug leads to any alterations in activity. However, it is interesting to note that the administration of cyproterone acetate does cause an increase in activity.
INVESTIGATIONS INTO THE EFFECTS OF CYCLICAL RHYTHM AND HORMONAL CONTRACEPTION ON SERUM FAT-MOBILIZING ACTIVITY, GLYCEROL, CHOLESTEROL AND BLOOD GLUCOSE
Authors: Curtis-Prior P. B. , Brewer H. F. Nicola , Temple N. J. , Ross Linda , Field D. A.
Published: December 2008

The effects were investigated of cyclical rhythm and hormonal contraception on serum fat-mobilizing activity, glycerol, cholesterol and whole blood glucose during 2 menstrual cycles in a group of normally menstruating young women and a second group of young women using hormonal contraception. A control group of normal young men was also investigated. There was no evidence of any change in mean level of any of the parameters measured, among the follicular, ovulatory and luteal phases. No cyclical pattern was discernable in the male subjects. The mean value for serum cholesterol concentration in women using hormonal contraception was higher than the value for the untreated human female group. The overall mean value for serum glycerol concentration in the women was significantly (0.01 > P > 0.001) higher than the mean value obtaining in the men.
THE EFFECT OF MESTEROLONE ADMINISTRATION TO NORMAL MEN ON THE PITUITARY-TESTICULAR FUNCTION
Authors: Aakvaag A. , Strømme S. B.
Published: December 2008

Mesterolone (1α-methyl-5α-dihydrotestosterone) has been given to 10 normal men, age 24–27 years, and the effect on the plasma levels of ICSH, FSH and testosterone has been studied.

No effect on the plasma levels of ICSH and FSH could be detected. After 4 weeks on 75 mg mesterolone per day a significant (P < 0.01) drop in the mean value for plasma testosterone level was observed, 5.2 to 4.0 ng/ml. After another 4 weeks on 150 mg mesterolone per day a further decrease to 3.5 ng/ml was found.

During mesterolone administration the protein binding of testosterone in plasma was significantly reduced, and it appeared that the level of free (non-protein bound) testosterone in diluted plasma remained unchanged, 0.37 and 0.41 ng/ml, before and after mesterolone administration respectively.

The results suggest that mesterolone given in doses of 75 and 150 mg/day to normal men does not suppress the pituitary ICSH production or the testicular testosterone production.
HETEROLOGOUS RADIOIMMUNOASSAY FOR PLASMA HUMAN PROLACTIN (hPRL); VALUES IN NORMAL SUBJECTS, PUBERTY, PREGNANCY AND IN PITUITARY DISORDERS
Authors: Aubert M. L. , Grumbach M. M. , Kaplan S. L.
Published: December 2008

A heterologous radioimmunoassay for human prolactin (hPRL) was developed, using a rabbit anti-ovine PRL (oPRL) which cross-reacted with hPRL and hPRL (Lewis 203-1) as tracer and standard. The sensitivity (0.02 ng hPRL) and the values obtained were comparable to those in homologous assays. When the immunoreactivity of a variety of hPRL preparations was compared, Friesen-71 hPRL was the most immunoreactive preparation, Lewis 203-1 and 201-195-1 hPRL had 75.6%, Friesen-C hPRL 54.4 %, and the Medical Research Council Standard (# 71-222) 27.5% of the immunoreactivity of Friesen-71 hPRL. hPRL content in 6 hGH preparations ranged from 0.001 to 0.2 %. Antibodies to hPRL were detected in 2 anti-hGH sera. The mean concentration of plasma hPRL in adult females (8.5 ± 1.5 ng/ml ± se) was significantly higher than in males (5.2 ± 0.5; P = 0.025). Plasma values of hPRL in girls between 4 and 17 years of age (7.2 ± 0.5) were not significantly different than in boys of the same age (6.0 ± 0.5). No variation in basal levels was found during puberty in girls, or with age in boys. The concentration of plasma hPRL was increased in pregnant women, newborn infants and in patients with galactorrhoea. Anencephalic infants had hPRL levels comparable to healthy newborns. The mean concentrations of plasma hPRL in patients with idiopathic isolated hGH deficiency or with idiopathic multiple pituitary hormone deficiencies were significantly higher than in normal subjects. Low to normal basal levels were measured in patients with hypothalamic tumour. Eight of 22 acromegalic patients had elevated hPRL levels; 5 female acromegalics had a significant rise in plasma hPRL values following injection of synthetic thyrotrophin releasing factor (TRF), but no increase after luteinizing hormone releasing factor (LRF). In conclusion, the heterologous radioimmunoassay for hPRL, using an anti-oPRL serum, has the requisite specificity, sensitivity, precision and reproducibility for clinical use.
OPPOSITE EFFECTS OF ANDROGENS AND OESTROGENS ON RAT PITUITARY THYMIDINE KINASE ACTIVITY
Authors: Valotaire Yves , Duval Jacques
Published: December 2008

Thymidine kinase has been tested in the male rat anterior pituitary. It increases after castration, but the daily injection of 3α-androstanediol starting immediately after gonadectomy prevents this increase. 3α-androstanediol is thus at least as active as testosterone and 5α-dihydrotestosterone. If regulation of thymidine kinase by androgens occurs directly in the pituitary, the regulation could take place at a post-transcriptional level, since androstanediol (free and protein-bound) is found almost exclusively in the cytoplasm.

Cyproterone injected to gonadally intact males (2 injections of 10 mg each) does not alter the thymidine kinase activity; thus this antiandrogen does not act in the same way as acute castration.

Oestradiol induces an increase of thymidine kinase specific activity either in the intact or in the castrated male. Two doses of 0.1 μg or of 100 μg are almost equally effective, suggesting a great sensitivity to oestrogens of this specific metabolic pathway in the regulation of DNA biosynthesis. There is apparently no competition between androgens and oestrogens; this could be explained by the existence of different target cells, i. e. androgens acting essentially on gonadotrophs and oestrogens on whole cells.
ISOLATION OF DESIALYLATED AND LOW-IODINATED THYROGLOBULIN IN AN EXPERIMENTAL RAT THYROID TUMOUR
Authors: Monaco F. , Grimaldi S. , Scuncio G. , Andreoli M.
Published: December 2008

In an experimental rat thyroid tumour (Wollman line 1-1C2) thyroglobulin (TG) was isolated from soluble iodoproteins by ammonium sulphate fractionation and density gradient ultracentrifugation. The isolated TG was characterized by polyacrylamide gel electrophoresis, microimmunodiffusion, immunoelectrophoresis, analytical ultracentrifugation and by chemical determination of sialic acid and iodine content.

Tumour thyroglobulin has a sedimentation coefficient of 17.7S, which is similar to that of enzymatically desialylated thyroglobulin (18.4S) in the normal rat; tumour TG shows a slower electrophoretic mobility than native TG and similar to rat desialylated TG.

In double immunodiffusion tumour TG is shown to precipitate with an identity reaction with both native and desialylated rat TG; in immunoelectrophoresis it has a slower migration than native TG and is very close to that of enzymatically desialylated TG. Tumour TG has an iodine content of 0.02 % and a sialic content of 0.15 %. Chromatography of the 125I-labelled tumour TG revealed the presence of mono- and diiodothyrosines, a very small amount of triiodothyronine but no thyroxine.

These results suggest that tumour TG, isolated in the experimental rat thyroid tumour, previously shown not to incorporate sialic acid into thyroglobulin, has a different electrophoretic mobility from native TG but is very similar to desialylated rat TG and has a very low sialic acid and iodine content as well as a striking decrease in thyroxine.
ACUTE EFFECTS OF GONADOTROPHINS AND PROSTAGLANDINS ON THE METABOLISM OF ISOLATED OVARIAN FOLLICLES FROM PMSG-TREATED IMMATURE RATS
Authors: Nilsson Lars
Published: December 2008

Pre-ovulatory follicles from immature rats injected with a low dose of PMSG have been used for studies of carbohydrate and protein metabolism in vitro. The follicles were isolated by free-hand dissection and incubated in modified Krebs bicarbonate buffer for periods up to 4 h. The lactic acid content of the medium was analyzed after various incubation periods. In most experiments the tissue uptake of [14C]α-amino-isobutyric acid and [3H] leucine as well as the incorporation of [3H] leucine into follicular protein were determined.

Addition of LH or FSH to the incubation medium markedly stimulated the production of lactic acid, whereas prostaglandins of the E-type were less effective. Prostaglandin F2α and dibutyryl cyclic 3′, 5′-AMP had no effect at all. No in vitro effects were seen on the uptake and incorporation af labelled amino acids. When LH or FSH was injected to the animals in vivo 1 or 2 h before incubation of the follicles, the lactic acid production was also stimulated, but only the injection of LH stimulated the protein incorporation of [3H] leucine.
CHARACTERISTICS OF THE CYCLIC 3′, 5′-AMP FORMATION IN ISOLATED OVARIAN FOLLICLES FROM PMSG-TREATED IMMATURE RATS AFTER STIMULATION IN VITRO WITH GONADOTROPHINS AND PROSTAGLANDINS
Authors: Nilsson Lars , Rosberg Sten , Ahrén Kurt
Published: December 2008

Isolated pre-ovulatory follicles from PMSG-injected immature rats, described in a previous publication, have been used for the investigation of the pattern of cyclic 3′,5′-AMP synthesis after in vitro addition of gonadotrophins and prostaglandins. The follicles were incubated in a modified Krebs bicarbonate buffer for periods up to 4 h and the cyclic 3′,5′-AMP content in tissue and medium was analyzed with the protein binding assay of Gilman (1970).

Addition of LH, FSH or prostaglandin E2 (PGE2) increased the cyclic 3′,5′-AMP level in follicular tissue dramatically. HCG and TSH, but not STH or prolactin, also induced a similar increase. The effect of FSH was blocked by a highly specific antiserum to LH. The effect of LH had a maximum after approximately 1 h of incubation, whereas the maximal effect of PGE2 was seen between 5 and 15 min of incubation. When LH was present in the incubation medium a significant release of cyclic 3′,5′-AMP into the medium occurred. Theophylline potentiated the effects of LH and PGE2.

The different time-courses of the effects of LH and PGE2 on the cyclic 3′,5′-AMP production by follicular tissue are discussed in relation to the hypothesis of prostaglandins as obligatory mediators of all LH effects on the ovary (Kuehl et al. 1970).
OVARIAN SECRETION RATES OF OESTROGENS, ANDROGENS AND PROGESTERONE IN NORMAL WOMEN AND IN WOMEN WITH PERSISTENT OVARIAN FOLLICLES
Authors: de Jong F. H. , Baird D. T. , van der Molen H. J.
Published: December 2008

The concentrations of oestradiol-17β, oestrone, androstenedione, testosterone, dehydroepiandrosterone, dehydroepiandrosterone sulphate and progesterone were measured in ovarian venous plasma from one or both ovaries in 4 normal women during different stages of the menstrual cycle and in 4 women with persistent ovarian follicles. In addition the steroid concentrations in peripheral plasma and follicular fluid were estimated. All steroids mentioned, with the exception of dehydroepiandrosterone sulphate, were secreted by the ovaries. The concentrations of oestradiol-17β, oestrone, androstenedione and progesterone were higher in the venous plasma from the ovary containing the developing follicle or corpus luteum than in venous plasma from the contralateral ovary. There was a good correlation between ovarian secretion of the oestrogenic steroids and androstenedione.

Finally, the quantitative contribution of the ovarian secretion to the blood production rates of the androgens and progesterone was calculated. The only contributions exceeding 20 % of the blood production rate were those of progesterone and androstenedione during the second half of the cycle.
EVIDENCE FOR A SEPARATE ADENYLATE CYCLASE SYSTEM RESPONSIVE TO BETA-ADRENERGIC STIMULATION IN THE RENAL CORTEX OF THE RAT
Authors: Bell Norman H. , Fleming John , Benedict Joanne , Pantzer Lisa
Published: December 2008

Previous studies in other laboratories had indicated that some of the effects of parathyroid hormone on skeletal tissue and the renal tubule to influence ion metabolism can be produced by beta-adrenergic stimulation. Studies were carried out to determine whether the same adenylate cyclase system in rat renal cortex is activated by parathyroid hormone and isoproterenol. At maximal effective concentration of dose response, parathyroid hormone (2 × −5 m) increased adenylate cyclase activity by some 415 per cent, isoproterenol (10−6 m) increased activity by some 40 to 50 per cent, vasopressin (10−5 m) increased activity by some 96 per cent and porcine calcitonin (10−5 m) increased activity by some 92 per cent. Dl-propranolol (10−5 m), a beta-adrenergic receptor blocking agent, prevented the increase in enzyme activity produced by isoproterenol (10−6 m), did not diminish the increase in activity produced by parathyroid hormone (10−6 m) and did not influence basal adenylate cyclase activity by itself. The combined maximal concentrations of isoproterenol together with either parathyroid hormone, vasopressin or porcine calcitonin were additive. These results indicate that there is an adenylate cyclase system in rat renal cortex which can be activated by beta-adrenergic stimulation with isoproterenol, and is separate from the systems responsive to parathyroid hormone, vasopressin or calcitonin.
EFFECT OF OESTRADIOL BENZOATE ON PITUITARY AND TESTIS FUNCTION IN THE NORMAL ADULT MALE RAT
Authors: Verjans H. L. , de Jong F. H. , Cooke B. A. , van der Molen H. J. , Eik-Nes K. B.
Published: December 2008

The effects of subcutaneous administration of oestradiol benzoate (EB) on the weights of sex organs and on levels of testosterone and gonadotrophins in normal adult male rats have been studied. Doses of EB varied from 0.01 to 100 μg and were administered daily for seven days. Administration of 100 μg EB resulted in suppression of pituitary LH, while serum LH levels were already decreased after treatment with EB ≧ 1 μg. Pituitary and serum FSH levels were suppressed after administration of 100 and 10 μg EB respectively. Testicular tissue and serum levels of testosterone decreased after treatment with amounts of EB ≧ 1 μg. These decreased androgen levels were also reflected in a concomitant decrease in the weights of the ventral prostate and seminal vesicles. A decrease in the weight of the testes was obtained following a dose of EB ≧ 10 μg.
AN IMPROVED IN VITRO BIOASSAY METHOD FOR MEASURING LUTEINIZING HORMONE (LH) ACTIVITY USING MOUSE LEYDIG CELL PREPARATIONS
Authors: Van Damme M.-P. , Robertson D. M. , Diczfalusy E.
Published: December 2008

An improved in vitro bioassay method for the measurement of LH activity is presented. The method is based on the assay of testosterone produced by "Leydig cell" preparations from mouse testes in the presence of added gonadotrophin. The method is significantly improved in terms of sensitivity, precision and practicability when compared to the previously described bioassay method employing decapsulated testes from adult mice. The sensitivity of the improved method is 15 μIU for HCG and 50 μIU for HMG. The useful range of the method is 15–260 μIU for HCG and 50–900 μIU for HMG. Using a 3 + 3 point assay design with each dose in quadruplicate, a mean index of precision (λ̅) of 0.044 was obtained in 19 assays.

Human FSH, TSH, ACTH, LTH, STH, oxytocin, vasopressin and LHRH preparations did not influence the bioassay method at levels likely to be found in biological samples. A good correlation was found between estimates obtained by the "Leydig cell" method and by the method using decapsulated testes when various HCG and HMG preparations were used. With the proposed method at least 30 samples can be assayed each week by 2 persons, with a marked reduction in cost.
DECREASED ARGININE-INDUCED HGH RESPONSE DURING L-DOPA THERAPY IN PARKINSONIAN PATIENTS
Authors: Johnson S. E. , Norman N. , Sjaastad O.
Published: December 2008

A study has been carried out in 8 patients with Parkinson's disease in order to measure the growth hormone response to arginine before treatment with L-DOPA and during such treatment. A significant lowering of the HGH response was found during treatment.
PRODUCTION AND EVALUATION OF GLUCAGON ANTIBODIES FOR RADIOIMMUNOASSAY
Authors: Holst J. J. , Aasted B.
Published: December 2008

Antiglucagon antibodies were raised in rabbits against glucagon covalently linked to bovine serum albumin. We followed three different immunization schemes in order to investigate the role of immunization frequency. The animals were bled regularly and their sera analysed for titre, avidity, and specificity of glucagon antibodies. Immunization frequency could not be correlated to any of the parameters investigated. Antigen dose, however, and persistence of immunization seem to be of importance. After 9 months 22 out of 30 animals immunized yielded antisera with an avidity suitable for radioimmunoassay. Nine of these antisera could be diluted to more than 1:96 000, 8 yielded detection limits below 25 pg/ml, 4 were relatively specific for pancreatic glucagon, and 5 reacted equally well with pancreatic and gut glucagon.
GONADAL FACTORS REGULATING THE ACTIVITY OF THE 17β-HYDROXYSTEROID OXIDOREDUCTASE IN RAT LIVER
Authors: Thaler-Dao H. , Breuer H.
Published: December 2008

The activity of the 17β-hydroxysteroid oxidoreductase (17β-HSOR), catalysing the oxidoreduction of oestradiol-17β and oestrone, has been studied in the cytosol fraction of rat liver under various conditions. The activity of the enzyme increased during maturation and reached a plateau at 100 days in females and at 180 days in males. In adult male rats, the activity of the 17β-HSOR was about 60% higher than in adult female rats. When female animals were castrated, the development of enzyme activity was similar to that observed in male rats; there was no difference in enzyme activity between adult castrated female rats and normal male rats. In normal female rats the activity of the 17β-HSOR was high during metoestrus and dioestrus, and low during pro-oestrus and oestrus. These findings show that oestrogens have a repressing effect on the activity of a key enzyme of steroid metabolism in rat liver.
LH AND FSH IN SERUM AFTER INTRAMUSCULAR ADMINISTRATION OF LH/FSH-RELEASING HORMONE IN NORMAL AND HYPOGONADAL MEN
Authors: Jørgensen F. Schønau , Kampmann J. , Micic S. , Roos J. , Johnsen Svend G.
Published: December 2008

The increase in serum concentrations of LH and FSH after intramuscular administration of LH/FSH-RH was investigated in normal and hypogonadotrophic hypogonadal males. LH and FSH were measured by specific radio-immunoassays. To evaluate the appropriate dose of LH/ FSH-RH for intramuscular administration different doses were administered and with 200 μg an increase in LH and FSH was found comparable to the results obtained by other investigators using intravenous administration. After the initial studies a simple test including two determinations before LH/FSH-RH administration and one 60 min and 120 min after administration was developed and used in all cases. In 12 normal males a significant increase in the serum concentration of both LH and FSH was found averaging 381 % and 148 % respectively 60 min after 200 μg LH/FSH-RH with a slight decrease in LH but not in FSH after 120 min. A positive response similar to that in normal men was observed in 11 hypogonadotrophic hypogonadal patients presenting different clinical pictures. This indicates that in all these patients the hypogonadotrophic state was due to a hypothalamic defect and not to a hypophyseal disorder.
THYROXINE DISSOCIATION IN HUMAN PLASMA: MEASUREMENT OF ITS RATE BY A CONTINUOUS-FLOW DIALYSIS METHOD
Authors: Hillier A. P.
Published: December 2008

A method is described for measuring the rate at which thyroxine dissociates from binding proteins in human plasma. The method depends upon the fact that free thyroxine is able to diffuse through Visking dialysis membrane whereas bound thyroxine cannot. At 20°C half of the plasma thyroxine dissociates within about 200 seconds and 75% within 10 min. At 37°C half of the hormone dissociates in less than 20 seconds and the reaction is virtually complete in 3–4 min. These values agree well with those previously obtained by a resin-uptake method. In the Discussion it is calculated that the pool of free thyroxine in the plasma is replenished about 5 × 106 times each day and that an individual thyroxine molecule spends only about 15 mseconds in free solution during each transit.
INTERACTION OF CONTRACEPTIVE PROGESTINS AND RELATED COMPOUNDS WITH THE OESTROGEN RECEPTOR
Authors: van Kordelaar M. G. , Broekman M. M. M. , van Rossum J. M.
Published: December 2008

The distribution pattern of oestradiol in ovariectomized rats as a function of time has been studied following intravenous administration of the tritiated hormone. Oestrogen specific binding with limited capacity was observed in the uterus, vagina, anterior pituitary, adrenals, preoptic area, hypothalamus, amygdala, septum and tractus diagonalis. Maximal uptake of oestradiol in the pituitary occurred within 5 min, in the uterus 60 min after injection, and remained almost unchanged at this level for more than two hours. The binding capacity per mg tissue decreased in the order pituitary, uterus, vagina, preoptic area, adrenals, hypothalamus, amygdala, septum and tractus diagonalis.

The hormone concentration in these tissues one hour after [3H]oestradiol injection was lowered by previous administration of ethinodiol, norethinodrel, lynestrenol and norethindrone, whereas medroxyprogesterone, chlormadinone, megestrol and methyllynestrenol had no effect. The same results were obtained, when instead of the steroid alcohols the corresponding acetate esters were administered. For norgestrel, oestrenol and nortestosterone the effect in the dose range studied was limited to the pituitary and preoptic area.

For lynestrenol the inhibition of oestradiol binding in the target tissues was almost the same when the progestin was given 60 and 5 min before oestradiol, whereas in the case of administration 30 min after oestradiol no inhibition was observed. The reduction of oestrogen binding appeared to be dose-dependent, but the dose required to obtain a certain effect for the uterus was four times as high as for the pituitary.

Discrepancies between previous studies and the implications of the present findings for the mechanism of action of ovulation inhibition by these progestins are discussed.
INTERACTION OF CONTRACEPTIVE PROGESTINS AND RELATED COMPOUNDS WITH THE OESTROGEN RECEPTOR
Authors: van Kordelaar J. M. G. , Vermorken A. J. M. , de Weerd C. J. M. , van Rossum J. M.
Published: December 2008

Incubation of the 105 000 × g supernatant of rat uterus homogenate with [3H] oestradiol resulted in an oestrogen specific binding of limited capacity to a macromolecule sedimenting in the 8–9S region after density gradient centrifugation. The contraceptive progestins of the 19-nortestosterone series were able to interfere with oestradiol binding in contrast to the hydroxyprogesterone derivatives chlormadinone, medroxyprogesterone and megestrol. The interaction appeared to be competitive. The strongest inhibition of oestradiol binding was observed in the presence of ethinodiol, followed by norethinodrel, lynestrenol and norethindrone respectively. Norgestrel was almost inactive. Of the related structures tested oestrenol displayed more activity than norethindrone, nortestosterone and ethisterone were less active and 6α-methyllynestrenol showed only border-line activity.

In comparison with norethinodrel and norethindrone, lynestrenol and oestrenol appeared in vitro to be stronger competitors for oestradiol than in vivo (Part I; Van Kordelaar et al. 1975). This may be due to the great difference in lipophilic character, which is reflected in the RM values of these compounds.

From the results obtained it may be concluded, that the presence of a 17α-ethynyl substituent promotes receptor binding, whereas the introduction of methyl substituents in the positions 6, 10 and 18 causes the opposite effect. The relationship between the various ring A structures and the affinity to the receptor is discussed.