RESUMO
Testosterone enanthate [TE] due to its anabolic effects is widely used by athletes to increase muscle strength. Despite widespread abuse of anabolic steroids, the endocrine effects of supraphysiologic doses of these compounds remain unclear. Our previous studies showed that the high doses of TE have some effects on the secretion of metabolic hormones. The aim of this study was to evaluate the effect [s] of high dosage of TE on serum levels of adrenocortical hormones in rat.In this study, 120 male Charles River rats [210-220g] were divided to five groups of 24. In group I, the control group, rats did not have any operation or injection. In group II rats were gonadectomized and received TE [5mg/100g B.W, i.p injection, weekly]. Group III was gonadectomized rats receiving vehicle [olive oil]. Group IV was sham-operated non-gonadectomized rats receiving the same dose of TE as group II. Group V was sham operated non-gonadectomiced rats receiving vehicle. In each group, blood samples were taken from eight rats after 21, 42, 63 days and the serum levels of testosterone, cortisol, aldostrone and corticotropin [ACTH] were measured by radioimmunoassy technique.The results showed that cortisol and aldostrone levels in TE receiving groups, were significantly lower and ACTH was higher than those of the other groups at day 21 [P<0.05]. In long term [63 days] these changes came back to the control levels.It seems that acute suppressive effects of high testosterone level on adrenocortical cells, decrease serum levels of cortisol and aldostrone and elavate ACTH. In long-term the feedback mechanisms modulate these effects via hypothalamic-hypophysial-adrenal axis
RESUMO
Thyroid gland dysfunction is associated with disorders of female reproductive functions. The aim of this study was to examine the effects of hyperthyroidism on ovulation rate and peripheral sex steroid levels in prepubertal and adult rats. Two groups of female rats aging 30 days [prepubertal rats] and 60 days [adult rats] were made hyperthyroid by oral administration of levothyroxine daily. In the two control groups [n=10] rats with the same ages received the same volume of normal saline. After 10 days the serum levels of T[3], T[4], LH, FSH, estradiol and progesterone were measured by RIA technique and also sections of ovaries were prepared for histological studies. All ovarian follicles and corpora lutea were counted to estimate ovulation rate. The results indicated that serum estradiol and progesterone levels of adult hyperthyroid rats were significantly lower than those of the control group [p<0.05]. However, there was no significant difference between estradiol levels in the prepubertal hyperthyroid group and its control group. In the hyperthyroid groups the mean number of primary, secondary and antral follicles and corpora lutea was significantly less than those of control groups. It was concluded that high levels of plasma thyroid hormones resulted in lowered body weight and disturbed ovarian follicle development and differentiation leading to reduction in ovarian steroidogenesis and ovulation