Effect of testosterone supplementation on nitroso-redox imbalance, cardiac metabolism markers, and S100 proteins expression in the heart of castrated male rats.

The aim of this study was to investigate the effects of castration and testosterone supplementation on nitroso-redox status, cardiac metabolism markers, and S100 proteins expression in the heart of male rats. 50 male Wistar rats were randomized into five groups with ten animals each: group 1: control intact (CON); group 2: sham operated (Sh-O); group 3: sesame oil-treated rats (S-oil); group 4: gonadoectomized (GDX); and group 5: gonadoectomized rats treated with testosterone (GDX-T) for 8 weeks. Our results showed myofibrillar weaving, apoptosis, inflammation, and fibrosis (as reflected by increased activity of MMP 9 and MMP 2) in the heart of gonadoectomized rats. Testosterone supplementation restored the normal structure of the heart. In addition, a state of nitroso-redox imbalance was observed in the heart of castrated rats with increased NO (425.1 ± 322.8 vs. 208 ± 67.06, p Ë‚ 0.05) and MDA (33.18 ± 9.45 vs. 22.04 ± 7.13, p Ë‚ 0.05) and decreased GSH levels (0.71 ± 0.13 vs. 1.09 ± 0.19, p = 0.001). Testosterone treatment leads to a re-establish of only NO levels (425.1 ± 322.8 vs. 210.4 ± 114.3, p > 0.05). Markers of cardiac metabolism showed an enhancement of LDH activity (12725 ± 4604 vs. 5381 ± 3122, p Ë‚ 0.05) in the heart of castrated rats. This was inversed by testosterone replacement (12725 ± 4604 vs. 5781 ± 5187, p Ë‚ 0.05). Furthermore, castration induced heart's accumulation of triglycerides (37.24 ± 6.17 vs. 27.88 ± 6.47, p Ë‚ 0.05) and total cholesterol (61.44 ± 3.59 vs. 54.11 ± 7.55, p Ë‚ 0.05), which were significantly reduced by testosterone supplementation (29.03 ± 2.47 vs. 37.24 ± 6.17, p Ë‚ 0.05) and (47.9 ± 4.15 vs. 61.44 ± 3.59, p Ë‚ 0.001). Cardiomyocytes of castrated rats showed a decreased immunoexpression of S100 proteins compared to control animals. A restoration of S100 proteins immunostaining in cardiomyocyte cytoplasm was observed after testosterone supplementation. These findings confirm the deleterious effects of testosterone deficiency on cardiac function and highlight the involvement of nitric oxide, metalloproteinases 2 and 9, and S100 proteins.

Purification, preliminary characterization and immunohistochemical localization of POSVP21 in the sand rat (Psammomys obesus) seminal vesicles.

The sand rat Psammomys obesus is a mammalian species with male seasonal reproduction. Previously Gernigon et al. (1994) [Gernigon T, Berger M, Lecher P. Seasonal variations in the ultrastructure and production of androgen-dependent proteins in the seminal vesicles of a saharian rodent (Psammomys obesus). J Endocrinol 1994;142:37-46.] reported that the seminal vesicles of the adult sand rat contained a major secretory protein band (M.W. 21000) regulated by testosterone. This protein is synthesized in large amounts when the androgen level increases, and accounts for over 22% of soluble proteins from homogenate of seminal vesicles during the breeding season. When analyzed by NepHGE the protein band of 21kDa appeared to be composed of at least 3 visible spots with pHi values varying from 4 to 7. Its partially internal sequence was identified and exhibited five peptides. Polyclonal antibodies against POSVP21 were obtained in rabbits. They were also used to study immunohistochemical antigen localization by the means of an avidin-biotin peroxidase procedure. Observation showed that it is localized in the cytoplasm of epithelial cells and in secretory products in the lumen. The whole RNA of seminal vesicles was translated in a cell-free system derived from rabbit reticulocyte lysate and [35S]-methionine. Two major bands of 14.4 and 21kDa were visualized by means of denaturing gel electrophoresis. SDS-PAGE from medium incubation of seminal vesicle tissue with [35S]-methionine revealed one band with an apparent molecular weight of 21kDa. The results obtained indicate that seminal vesicle epithelium is the site of POSVP21 synthesis and the comparison of the partial amino acid composition of the internal sequence, indicated that POSVP21 constitute a family of most unusual proteins.

Comparative study of the effects of pre and post natal administration of a thyroid drug on testicular activity in adult rat.

Thyroid hormone is known to play a critical role in growth and development of rat testes with a specific effect on the differentiation of Sertoli cells leading to a normal evolution of germ cells. In the present study, we aimed to compare the effect of induced hypothyroidism during fetal and post-natal life on the structure and function of the testis in adult. Pregnant or lactating mothers were treated with 6-propyl-2-thiouracil (PTU) during 21 days and weight gain of pups was steady until adult age. Plasma hormonal levels were determined by RIA and morphology of testis was studied on sections stained with Masson's trichrome. Pre and early post natal hypothyroidism resulted in an impairment of body development and a diminution of thyroid hormone levels of treated rats. No significant effect on testicular development has been observed when hypothyroidism is induced in fetal life while it was associated with reduction in testis weight, diameter of seminiferous tubules and hormonal levels and delay in maturation of germ cells, when induced during early post natal life.

[Ultrastructural immunocytochemical localization of hormonal principles of the adenohypophysis in the terrestrial tortoise (Testudo mauritanica Dumer)]. / Localisation par immunocytochimie ultrastructurale des principes hormonaux de l'adénohypophyse de la tortue terrestre (Testudo mauitanica Dumer).

An ultrastructural immunocytochemical study is realized with mammalian adenohypophyseal anti-hormone antibodies and permits characterization of five cellular types in Testudo mauritanica Dumer. The antiproteic-hormone antibodies STH, LTH and ACTH are each fixed on a well individualized cellular type. The anti-glycoproteic hormone antibodies identify a TSH cell; but two cell populations respond to the same beta LH antigonadotropic antibody. The question of the unicity or the duality of the gonadotrope cells is expressed.