bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study of Δ5-3β-hydroxysteroid dehydrogenase in human foetal adrenal glands
Authors: Hirato Kumiko , Yanaihara Takumi , Nakayama Tetsuya 
Published: December 2008

Abstract.
'Microsomal fractions' of foetal adrenal tissue obtained at 18–24 weeks of gestation were incubated with several radioactive Δ5-3β-hydroxysteroids to study the properties of Δ5-3β-hydroxysteroid dehydrogenase (Δ5-3β-HSD)1. Incubations were performed under CO gas to inhibit hydroxylation. Enzyme activity was measured by the conversion of pregnenolone, 17α-OH-pregnenolone, dehydroepiandrosterone, androstenediol and androstenetriol to the corresponding Δ4-3-oxo-steroids. 17α-OH-pregnenolone was the most preferred substrate for the enzyme among the Δ5-3β-substra-teroid substrates examined. Michaelis constants (Km) of Δ5-3β-HSD were 2 × 10−4 m for pregnenolone, 7.2 × 10−6m for 17α-OH-pregnenolone and 7.8 × 10−6 m for dehydroepiandrosterone. No significant amounts of Δ4-3-oxosteroids were produced from androstenediol and androstenetriol, and Km values for them were not determined. The enzyme preferred NAD+ to NADP+ as a hydrogen receptor and the Km for NAD+ was 1.1 × 10−4 m in the presence of 17α-OH-pregnenolone. The enzyme activity for 17α-OH-pregnenolone was competitively inhibited by dehydroepiandrosterone, suggesting that both Δ5-3βhydroxysteroids were catalyzed at the same site of the enzyme, and also non-competitively by oestriol. Other steroids produced by the foeto-placental unit which inhibited the enzyme activity for 17α-OH-pregnenolone were pregnenolone-3β-yl-sulphate, androstenediol, oestradiol17β, oestrone and oestradiol-17β-yl-sulphate. It appears likely that the formation of Δ4-3-oxo-steroids as precursors for cortisol synthesis in foetal adrenal glands is influenced by the presence of steroids produced by the foeto-placental unit.
Effect of insulin and epinephrine on some early oestrogenic responses in the rat uterus
Authors: Steinsapir J. , Rojas A. M. , Alarcón O. , Tchernitchin A. N. 
Published: December 2008

Abstract.
Oestradiol induces uterine eosinophilia and oedema, both in the intact immature rat and in the adult ovariectomized rat. These responses are decreased in ovariectomized-adrenalectomized adult rats, in adrenalectomized immature rats and in medullectomized immature rats. Pre-treatment with L-epinephrine restored both oestrogenic effects.
Insulin inhibits oestrogen binding by uterine eosinophils and concurrently decreases oestrogen-induced uterine oedema and eosinophilia. These phenomena do not occur with inactive insulin. Insulin also induces blood eosinopaenia, suggesting an explanation for the findings in the uterus.
Is 3α-androstanediol a marker of peripheral hirsutism?
Authors: Toscano Vincenzo , Sciarra Francesco , Adamo Maria Vittoria , Petrangeli Elisa , Foli Sonia , Caiola Stefania , Conti Carlo 
Published: December 2008

Abstract.
The behaviour of 5α-reduced metabolites of testosterone, dihydrotestosterone1, 3α-androstanediol and 3β-androstanediol, was studied in 36 hirsute women: Group I: 24 patients with high plasma levels of testosterone, androstenedione and/or dehydroepiandrosterone sulphate and Group II: 12 patients with normal plasma concentrations of these steroids.
Testosterone and its 5α-reduced metabolites were determined by radioimmunoassay after chromatographic separation on celite 535 microcolumns.
Plasma 3α-androstanediol was found to be elevated both in Group I (26.9 ± 10.8 sd ng/100 ml) and in Group II patients (23.2 ± 10.5 sd ng/100 ml). 3β-Androstanediol and dihydrotestosterone, on the contrary, were elevated in only a few cases: in 6 cases in Group I and in 2 and in 1 case, respectively, in Group II.
The finding of high plasma 3α-androstanediol levels in hirsute women, with normal values of the other androgens, may be an index of hirsutism of peripheral origin, since this steroid is produced almost exclusively in the extraglandular compartment.
Comparison of radioimmunoassay, chemical assay (HPLC) and bioassay for arginine vasopressin in synthetic standards and posterior pituitary tissue
Authors: Möhring J. , Böhlen P. , Schoun J. , Mellet M. , Süss U. , Schmidt M. , Pliška V. 
Published: December 2008

Abstract.
Radioimmunoassay and chemical assay (high performance liquid chromatography (HPLC) with fluorescence detection) for arginine vasopressin (AVP) in purified synthetic preparations and in posterior lobe tissue samples (ox and rat) yielded essentially identical values. In tissue samples from the neurohypophysis, the reproducibility of the former method was roughly twice as good. The routinely used blood pressure bioassay was very poorly reproducible and yielded values deviating from the two other methods. In all three assays, the coefficient of variation was roughly five times higher in tissue samples than in synthetic preparations. It is suggested that a chemical rather than a biological assay is used for standardization of AVP for radioimmunoassay. Large differences were found in the quality of AVP preparations potentially usable as standards and tracers (after iodination) for radioimmunoassay. All commercial preparations should therefore be checked for their AVP and impurity content by high performance liquid chromatography.
A prospective study of the differential changes in serum thyroglobulin and its autoantibodies during propylthiouracil or radioiodine therapy of patients with Graves' disease
Authors: Feldt-Rasmussen Ulla , Bech Karine , Date John , Petersen Per Hyltoft , Johansen Klaus 
Published: December 2008

Abstract.
Measurement of serum thyroglobulin (Tg) and its autoantibody (TgAb) by radioimmunological methods was performed in 48 patients with Graves' disease during treatment with radioiodine (n = 16) or propylthiouracil (PTU) (n = 32).
Twenty-five of the 48 patients were TgAb positive, their sera being inaccessible to measurement of serum Tg. TgAb showed only minor changes during PTU treatment, whereas TgAb fell rapidly after radioiodine, in 5 of 16 patients to unmeasurable levels, followed by a secondary rise to 4.5 times pre-treatment level after 20 weeks.
Serum Tg showed a steady increase during the first weeks after radioiodine treatment, but fell to lower levels after one year. PTU caused only minor changes in the serum Tg concentration. There was no shift in molecular sizes of either Tg or TgAb during the course of the treatments.
Five of 16 131I-treated patients developed myxoedema, 4 of whom were TgAb positive. Another 3 patients had high increases in TgAb without myxoedema.
Six of 18 patients had relapse of thyrotoxicosis after withdrawal of PTU-treatment. There was no significant difference in serum concentrations of TgAb or Tg between those developing relapse and those remaining in remission, and it is concluded that serum Tg is a poor predictor of relapse in medically treated thyrotoxicosis.
Factors influencing the release of cyclic AMP from mouse thyroid tissue stimulated by TSH in vitro
Authors: Gustafson Asa , Ahrén Bo , Hedner Pavo , Nilsson Hans 
Published: December 2008

Abstract.
The accumulation of cyclic AMP (cAMP) in mouse thyroid tissue in response to TSH in the presence of 1 mm theophylline was accompanied by a release of the nucleotide from the tissue into the incubation medium. This cAMP release was almost rectilinearly related to the time of exposure to TSH, and rectilinearly related to the log concentration of TSH in the range 0.1–5 mU/ml. The cAMP release proved to be independent of the pre-incubation time up to 4 h, and took place also in the absence of methylxanthines when the cAMP level was low. The total cAMP accumulation in response to TSH was augmented by different inhibitors of protein synthesis but the fraction of the nucleotide that was retained intracellularly was increased only by puromycin. Dipyridamole had an effect similar to that of puromycin. Depolarization or treatment with ouabain did not change the distribution of cAMP between tissue and medium.
It is concluded that the release of cAMP from thyroid tissue stimulated by TSH may take place under physiological conditions, that it seems to be regulated by the actual concentration of TSH, and that it may be of significance for the regulation of the intracellular cAMP level.
Insulin releasing action of 2-[2-(4,5-dihydro-1H-imadazol-2-yl)-1-phenylethyl] pyridine dihydrochloride sesquihydrate (DG-5128), a new, orally effective hypoglycaemic agent
Authors: Kameda Kin-ya , Ono Shin-etsu , Koyama Isao , Abiko Yasushi 
Published: December 2008

Abstract.
2-[2-(4,5-dihydro-1H-imidazol-2-yl)-1-phenyl-ethyl] pyridine dihydrochloride sesquihydrate (DG-5128) is a new orally effective hypoglycaemic agent structurally unrelated to the known hypoglycaemics. DG-5128 was found to decrease blood glucose levels by stimulating insulin release, like the sulphonylurea hypoglycaemics. However, the study with the rat Langerhans islets in vitro indicated a great difference in mode of stimulation of insulin release between DG-5128 and a sulphonylurea hypoglycaemic, tolbutamide. DG-5128 significantly reversed α-adrenergic inhibition of the glucose-primed insulin release from the islets, while tolbutamide did not. From the comparison with the effects of phentolamine, yohimbine and prazosine, DG-5128 was strongly suggested to stimulate the glucose-primed insulin release through antagonizing at α2-adrenoreceptors on the B cells.
Development of the gonadotrophic resistant ovary syndrome in myasthenia gravis: suggestion of similar autoimmune mechanisms
Authors: Escobar María Eugenia , Cigorraga Selva B. , Chiauzzi Violeta A. , Charreau Eduardo H. , Rivarola Marco A. 
Published: December 2008

Abstract.
A woman with myasthenia gravis who developed hypergonadotrophic amenorrhoea was studied. This patient fulfilled all accepted criteria for the diagnosis of the gonadotrophin resistant ovary syndrome: high levels of serum LH and FSH by radioimmunoassay and urinary gonadotrophin excretion by bioassay, low serum oestradiol, lack of response to exogenous gonadotrophin and ovaries with multiple non-stimulated primordial follicles.
The serum of this patient contained a substance which behaving like a gamma globulin, inhibited FSH specific binding to receptors in an in vitro system. This inhibitor was looked for in further patients with hypergonadotrophic amenorrhoea, other immunological diseases or myasthenia gravis with normal menses. Ovarian biopsy was not available in these patients. In all except one who also had the association of myasthenia gravis and hypergonadotrophic amenorrhoea, the inhibitor was not detected.
It is suggested that development of antibodies directed against gonadotrophin receptors or a receptor related membrane domain may play a role in the mechanism of failure of gonadotrophin stimulation in some patients with the gonadotrophin resistant ovary syndrome.
Effects of antibodies to catecholoestrogens and catecholoestrogen methyl ethers on PMS induced ovulations in immature rats
Authors: Ball Peter , Schwarzlose Christian , Emons Günter 
Published: December 2008

Abstract.
Endogenously formed catecholoestrogens or their monomethyl ethers were neutralized in the circulation using antisera with high affinity and specificity for 2-hydroxyoestrone and 2-hydroxyoestradiol or 4-hydroxyoestrone and 4-hydroxyoestradiol or the respective methyl ethers in PMS treated immature female rats.
The experimental arrangement used was valid as 1) animals treated with PMS and antiserum to oestrone and oestradiol failed to ovulate without impairment of body weight, 2) ovulations could be restored by injections of hCG at the time when rats treated with PMS alone had their ovulatory LH surge and 3) normal rabbit serum had no effect on ovulations and on body weight.
Treatment of the animals with antisera to catecholoestrogens or their methyl ethers had no negative effect on ovulation frequency, number and shape of ova and body weight, although the doses of antisera used — as calculated from the number of antibody binding sites and affinity constants — must have been more than sufficient to neutralize catecholoestrogens or their methyl ethers in the blood stream. In animals treated with PMS and a blocking dose of antiserum to oestrone and oestradiol ovulations could be restored by injections of 4-hydroxyoestradiol-dibenzoate following a regimen which procured plasma levels of 4-hydroxyoestradiol imitating the concentration/time course of endogenous oestradiol in animals treated with PMS alone.
We conclude that catecholoestrogens and their methyl ethers formed peripherally, are not of crucial importance for ovulation — at least in this model. 4-Hydroxyoestradiol, however, can completely replace the peripheral and physiologically essential oestradiol at central target sites when this primary oestrogen is neutralized by antibodies.
Effects of orchidectomy and sex steroids on vasopressin response to dehydration
Authors: Valiquette G. , Martini L. 
Published: December 2008

Abstract.
The secretion of vasopressin has been shown recently to be influenced by gonadal steroids. To further evaluate the relevance of sex steroids in the control of vasopressin secretion, the vasopressin response to dehydration has been studied in normal, castrated and sex-steroid treated castrated male rats.
Short-term (3 weeks) castration did not modify the vasopressin response to 48 h of water deprivation. Long-term (10 weeks) castration, on the other hand, consistently reduced the vasopressin response by more than 50%. In both cases, the osmolality was unaffected.
Treatment of long-term castrated rats with testosterone, dihydrotestosterone, or oestradiol increased the vasopressin response to dehydration towards normal control levels. However, only oestradiol could restore it to and beyond normal levels, although all three steroids were given in doses that were equipotent in bringing back to normal the plasma LH levels of the castrated animals.
Angiotensin-II generation may indirectly be augmented by oestradiol treatment and this may account for the effect of oestradiol here reported. No such mechanism, however, may be invoked in the case of androgens; a direct modulatory effect at the hypothalamic level is postulated for explaining their influence on vasopressin secretion.
131I treatment of diffuse and nodular toxic goitre with or without antithyroid agents
Authors: Bliddal Henning , Hansen Jens Mølholm , Rogowski Preben , Johansen Klaus , Friis Thorkild , Siersbæk-Nielsen Kaj 
Published: December 2008

Abstract.
The results of 131I treatment in combination with pre- and post-treatment with carbimazole (n = 122) were compared to the results of 131I used as the only antithyroid treatment (n = 203). The two groups of patients were fully comparable in regard to age, size of goitre and time of observation, and the same diagnostic criteria and dosage regimen of 131I were used. The incidence of early myxoedema in patients with diffuse goitre was significantly reduced after combination therapy, 5 per cent, compared to 16 per cent after 131I as the only antithyroid therapy (P < 0.05). The incidence of late myxoedema was 6 per cent in both groups 3 years after the last treatment, and fully compensated myxoedema was found in 13 and 22 per cent (n.s.). No severe acute side effects were observed after 131I therapy in any of the two groups. It is concluded that - in diffuse toxic goitre - a lower early incidence of myxoedema was obtained on the combined regimen because of either a possibly lower absorbed radiation dose or a more fractionate therapy. A major advantage of the combination therapy is also, that the patients are rendered euthyroid shortly after the diagnosis and remain so during the prolonged period of treatment. 131I treatment in combination with carbimazole is advocated in all patients with diffuse and nodular toxic goitre if the patient is above fertile age and thyroidectomy is not indicated.
Inhibition by calcium channel blockers of the glycogenolytic effect of glucagon in perfused rat liver
Authors: Kimura Satoshi , Matsumoto Toshio , Tada Ryoko , Ogata Etsuro , Abe Kaoru 
Published: December 2008

Abstract.
Verapamil and diltiazem, calcium channel blockers, inhibited significantly the glucagon-induced glucose output and 45Ca efflux from perfused rat liver at concentrations higher than 50 μm when the perfusate contained calcium. Although the blockers partially interfered with glucagon-induced elevation of cyclic AMP in the tissue, they also inhibited the effects of cyclic AMP. The blockers did not show the inhibitory effects in the absence of perfusate calcium. However, the inhibition of calcium influx into hepatocytes by omission of extracellular calcium or addition of EGTA did not interfere with these effects of glucagon and cyclic AMP. In the presence of extracellular calcium, the blockers did not inhibit cyanide-induced glucose output, indicating that the activity of glycogen phosphorylase and later processes leading to glucose output were not affected by the blockers. These data suggest that, in the presence of calcium, the blockers inhibit the effect of glucagon also at a step (or steps) subsequent to cyclic AMP production and before the activation of phosphorylase b, probably by inhibiting glucagon-induced mobilization of calcium from intracellular calcium pools rather than inhibiting calcium influx into hepatocytes.
46,XX gonadal absence: a variant of the XX pure gonadal dysgenesis?
Authors: Medina Martha , Kofman-Alfaro Susana , Pérez-Palacios Gregorio 
Published: December 2008

Abstract.
Two unrelated 46,XX individuals with female phenotype and sexual infantilism were studied. Endocrine findings showed anoestrogenism and hypergonadotrophism with a normal pituitary response to LRH. Laparotomy disclosed ovarian absence with normal Mullerian derivatives and no gonadal streaks were found within the true pelvis or inguinal canals.
This condition represents the 46,XX counterpart of the 46,XY gonadal absence syndrome. Whether the XX agonadism reported here is a different and distinctive entity or is a variant of the XX pure gonadal dysgenesis syndrome can not be ascertained at present.
Danazol has progestin-like actions on the human endometrium
Authors: Kokko E. , Jänne O. , Kauppila A. , Rönnberg L. , Vihko R. 
Published: December 2008

Abstract.
The administration of danazol, 200 mg three times daily, from the 3rd to the 23rd day of the cycle to normally menstruating women exhibited the following actions on the human endometrium: significantly reduced cytosol oestrogen and progestin receptor concentrations, and declined 17β-hydroxysteroid dehydrogenase activity. Very similar results were obtained during medroxyprogesterone acetate (100 mg daily) treatment for the same period of time. Danazol administration did not decrease circulating gonadotrophin levels but clearly suppressed luteal serum oestradiol and progesterone concentrations. Danazol was found to bind in vitro to endometrial progestin receptor with an affinity approximately 3% of that of progesterone. These findings are compatible with the notion that a local progestin-like rather than a systemic action of danazol is the way by which its therapeutic effect is exerted. This may be potentiated by the suppression of circulating oestradiol levels.
Identification of somatostatin in the human placenta
Authors: Lee Jau Nan , Wu Ping , Chard Tim 
Published: December 2008

Abstract.
High pressure liquid chromatography (HPLC), gel chromatography and radioimmunoassay (RIA) were applied to the identification of cyclic somatostatin in human placental tissue. Methanol extracts of the placenta were treated with acetic acid and chloroform, purified on an octadecylsilane column, fractionated on HPLC and gel filtration, and assessed by RIA. It is concluded that human placental somatostatin is similar or identical to cyclic somatostatin on other tissue.
Effects of oestradiol and levonorgestrel on lipoprotein lipids and postheparin plasma lipase activities in normolipoproteinaemic women
Authors: Tikkanen M. J. , Nikkilä E. A. , Kuusi T. , Sipinen S. 
Published: December 2008

Abstract.
The effects of oestradiol and levonorgestrel on plasma lipoprotein cholesterol (Chol) and triglyceride (Tg) levels and on postheparin plasma lipoprotein lipase (LPL) and hepatic lipase (HL) activity were studied in 52 normolipoproteinaemic women. The androgen-derived progestin levonorgestrel increased postheparin plasma hepatic lipase (PH-HL) activity and decreased plasma high-density lipoprotein (HDL) lipid concentrations in a manner opposite to that of oestradiol. The relationships between PH-HL activity and HDL lipids suggest an important role for this enzyme as a mediator of sex hormone action on HDL.
Effect of metoclopramide induced hyperprolactinaemia on the gonadotrophic response to oestradiol and LRH
Authors: Andersen A. Nyboe , Schiøler V. , Hertz J. , Bennett P. 
Published: December 2008

Abstract.
The effect of oral metoclopramide 10 mg three times daily during the follicular and periovulatory period on Prl, LH, FSH, oestradiol and progesterone was determined in 6 regularly menstruating women. During a control cycle and a treatment cycle the gonadotrophic response was measured after 1 mg oestradiol benzoate given im on the 8th day and after LRH 25 μg iv on the 8th and 11th day of the menstrual cycle. Prl, LH and FSH were also measured in 7 post-menopausal women either during short-term or long-term treatment with metoclopramide. Compared to a control cycle metoclopramide significantly (P < 0.01) increased serum Prl, but a sustained hyperprolactinaemia was not obtained in 2 women. Treatment significantly (P < 0.02) increased the LH and FSH responses to LRH and augmented the negative feedback of oestradiol on both LH and FSH (P < 0.05). A major gonadotrophin surge occurred in those 2 women where a sustained hyperprolactinaemia was not achieved. Oestradiol benzoate caused a significant increase of the LH (P < 0.01) and FSH (P < 0.05) responses to LRH after 72 h during the control cycle, but failed to increase either LH or FSH responses significantly during treatment. Short-term hyperprolactinaemia in post-menopausal women was not associated with any consistent alteration in either LH or FSH levels or pulsatility, but chronic treatment resulted in a significant reduction in serum FSH (P < 0.02), without any alteration in LH levels or pulsatility. LH and FSH responses to LRH increased in all. There was no effect on serum DHAs, urinary androgens or follicular phase serum progesterone levels.
These data show that moderate drug induced moderate hyperprolactinaemia is associated with an increased responsiveness of both LH and FSH to LRH, and has a more pronounced effect on the negative feedback compared to the positive feedback of oestradiol on gonadotrophin secretion. It is suggested that hypersecretion of Prl impairs periodic LH release, mainly through an altered feedback mechanism, but also has a direct inhibitory effect on FSH secretion.