Electronic Library of Scientific Literature
Volume 30 / No. 3 / 1996
A. Brtkova, J. Brtko
Research Institute of Nutrition, SK-83337 Bratislava;
Institute of Experimental Endocrinology, Slovak Academy of Sciences, SK-83306 Bratislava, Slovak Republic
Selenium occurs both in prokaryocytes and eukaryocytes as a component of selenoenzymes or selenoproteins. Approximately 80 % of selenium in animal or human body occurs in the form of seleno-L-cysteine, an amino acid encoded by one of standard termination codons. Selenium is an integral component of the active site of glutathione peroxidases which plays an important role in the antioxidant system. Iodothyronine 5-deiodinase, type I is also a selenoenzyme consisting of two identical subunits which catalyzes a reductive monodeiodination of iodothyronine residues of the phenolic ring. General characteristics of several selenoproteins and selenium binding proteins are summarized, also certain facts on the effects of selenium deficiency in man and its distribution and toxicity in higher organisms, are reviewed. Selenium status in the population from selected regions in Slovakia is reported and compared with that in other countries.
Key Words: Selenium - Deficiency - Metabolism - Requirements
- Selenoenzymes - Selenoproteins - Minireview
Teronuri Mitsuma, Masato Kayama, Nebi Rhue, Yoshifumi Hirooka, Yuichi Mori, Koshin Adachi, Jing Ping, Tsuyoshi Nogimori
Fourth Department of Internal Medicine and
Laboratory Medicine, Aichi Medical University, Nagakute, Aichi, Aichi 480-11, Japan and
Department of Internal Medicine, Konanshowa Hospital, Konan, Aichi, Japan
The effect of anti-thyrotropin-releasing hormone (TRH) receptor antibody on corticosterone release from the rat adrenal gland in vitro was studied. The adrenal glands were incubated in medium 199 with 1.0 mg/ml bacitracin (pH 7.4, medium) for 20 min and the release of corticosterone into the medium was measured by radioimmunoassay. TRH inhibited corticosterone release from the adrenal gland in a dose-related manner. The inhibitory effect of TRH on corticosterone release from the adrenal gland was prevented by the addition of anti-TRH-receptor antibody. The present findings suggest that TRH inhibits corticosterone release from the adrenal gland in vitro and its effect is mediated via TRH receptor.
Key words: Anti TRH Receptor Antibody - TRH - Adrenal Gland -
Z. Ostrowska, B. Buntner, K. Zwirska-Korczala, B. Marek, M. Nowak
1st Department of Pathophysiology and Clinical Biochemistry, Silesian Academy of Medicine, 41-800 Zabrze, Poland
Many clinical manifestations shown by obese women point to the disturbances of secretory activity of hypothalamus-pituitary-ovary axis (h-p-o). Because of antigonadotropic activity of melatonin (MEL) it is essential to define this hormone participation in inducing the disturbances of the h-p-o axis. We evaluated the relationship between MEL secretion and circadian concentrations of LH, FSH, E[_2], P, TT, FT, SHBG as measured at 3 h intervals, in 9 obese women showing android type of adipose tissue distribution (BMI > 30 kg/m[^2]; WHR > 0.8) and in 6 women showing gynoid type of adipose tissue distribution (BMI > 30 kg/m[^2]; WHR < 0.8). All patients were between 55 and 62 years of age. A considerable increase of circadian MEL secretion was observed in all obese patients. Suppression of MEL rhythmicity was observed in all patients, while nocturnal phase shift of MEL occurred only in women showing android type of adipose tissue distribution. Significant decrease of circadian LH, P and SHBG values which was accompanied by the elevation of E[_2], TT and FT levels was observed in women with a disturbed rhythmicity of MEL secretion (particularly in case of androidal-type obesity). Based on these results it is suggested that MEL participates in inducing h-p-o axis disturbances in obese women of post-menopausal age.
Key words: Android Obesity - Gynoid Obesity - Melatonin - Gonadotropins
- Sex Hormones - SHBG - Postmenopausal Age
Z. Ostrowska, B. Buntner, I. Banas, B. Kos-Kudla, B. Marek, K. Zwirska-Korczala
1st Department of Pathophysiology and Clinical Biochemistry, Silesian Medical Academy, 41-800 Zabrze, Poland
Circadian variations of salivary melatonin (MEL) were examined in 81 women (48 of reproductive and 33 of postmenopausal age), 16 of them with moderate overweight, 32 showing gynoid obesity (BMI>30 kg/m[^2]; WHR<0.8) and 33 showing android obesity (BMI>30 kg/m[^2]; WHR>0.8). The circadian profiles of salivary MEL in women with moderate overweight were parallel to those of controls. However, mean 24 h salivary MEL levels tended to be higher in all obese patients as compared with controls (mainly due to increase of its daytime levels). In addition, the suppression of MEL rhythmicity was observed in all subjects studied irrespectively of gynoid or android obesity, while nocturnal MEL peak shift was observed predominantly in the case of extreme obesity with android distribution of adipose tissue. Despite of increasing tendencies mean 24 h MEL concentrations and stronger suppression of circadian variations and/or nocturnal MEL peak shift in extremely obese women with android distribution of adipose tissue, no significant correlation was found between the values of BMI index, WHR ratio and circadian MEL concentrations.
Key words: Gynoid Obesity - Android Obesity - Salivary Melatonin
-Reproductive Age - Postmenopausal Age
S. Aich, C.K. Manna
Endocrinology Laboratory, Department of Zoology, Kalyani University, Kalyani 741235, Nadia, West Bengal, India
Adult male Indian house rats (Rattus rattus) were administered ethylene
glycol monomethyl ether (EGME) (500 mg/kg) perorally daily for 1, 6 and
11 days and were examined after 1, 6, and 11 days, respectively. Also a
recovery study was conducted for 4 and 8 weeks after the animals received
11 successive doses of EGME. EGME caused testicular lesions resulting in
a severe impairment of spermatogenic elements. However, no histopathological
changes of the Leydig cells or alterations in testicular steroidogenesis
After 24 hours of EGME treatment, normal cellular associations were observed except stages IX-XIV, while after 11 days of such medication, stages I-XIV could not be confirmed except in few tubules. At this stage 92.47 % of the cellular associations were unidentified. It is assumed that the depletion in the germ cell populations occurred due to the maturation arrest at the zygotene stage of the spermatocytes.
Sperm motility and sperm count were reduced in the treated animals. They were impaired with the advancement of treatment. The normal mounting and copulatory behavior and maintained testicular androgen levels suggested unimpaired libido. No morphological alteration could be visible in the Sertoli cells at the light microscopic level. Recovery of spermatogenesis was found after 8 weeks, indicating reversible toxicity of this dose, but the percentage of the frequency of occurrence of stage VII-VIII cellular associations failed to maintain its control level. These results showed that EGME medication induced reversible inhibition of spermatogenesis and rendered the male infertile.
Key words: Ethylene glycol monomethyl ether - Testes - Wild rats
- Spermiogenesis - Histochemistry - Sexual behavior
Krystyna Zwirska-Korczala, Zofia Ostrowska, Mieczyslaw Fryczkowski, Maciej Stronczak, Barbara Buntner
1st Department of Pathophysiology,
1st Department of Urology, Silesian Medical Academy, 41-800 Zabrze, Poland
The study was aimed at assessing the influence of prolonged (18-24 months) androgen treatment of 11 agonadal transsexual women on basal concentrations of LH, FSH, testosterone (T), estradiol (E2), progesterone (P) and SHBG, on the hypothalamic-hypophysial (GH, PRL, ACTH) and hypothalamic-adrenal (cortisol) response in insulin test and TSH and PRL response after TRH administration. Fifteen healthy women in follicular phase of menstrual cycle and 15 men served as controls. In TS women basal concentrations of E2 were comparable with those in healthy women in follicular phase and the lowered T value showed negative correlation with SHBG. In most TS women the stimulated secretion of GH, PRL, ACTH and cortisol in insulin test was diminished. Basal values of these hormones oscillated within normal range except ACTH levels which were higher as compared with control values. In most cases the PRL response to TRH was diminished, but in three patients excessive secretion of PRL was found. Long-term priming with androgen was found to produce a dramatic change in the patterns of hormonal response to post-insulin hypoglycaemia and TRH in female-to-male transsexuals. It was concluded that in prolonged treatment of agonadal transsexual women the doses of testosterone preparations should be adjusted to individual patients in order to monitor steroid and gonadotropin hormone values, as well as the response of pituitary hormones, particularly that of PRL, to stimuli.
Key words: Transsexual Agonadal Women - Gonadotropins - Sex Hormones
- SHBG - Insulin Test - TRH Test - Long-Term Androgen Therapy