Biosintesis de esteroides en el ovario

Growth hormone (GH) and anabolic androgenic steroids (AAS) are commonly used in sports communities. Several studies have suggested an association between GH and AAS. We have investigated the impact of GH in rats treated with nandrolone decanoate (ND). Male Wistar rats received ND (15 mg/kg) every third day during three weeks and were subsequently treated with recombinant human GH ( U/kg) for ten consecutive days. Plasma samples were collected and peripheral organs (. heart, liver, testis and thymus) were dissected and weighed. Concentration of thirteen endogenous steroids was measured in the rat plasma samples using high specificity LC-MS/MS methods. Seven steroids were detected and quantified, and concentrations of estrone, testosterone, and androstenedione were significantly different among the groups, while concentrations of pregnenolone, DHEA, 17-hydroxyprogesterone and corticosterone were not altered. Administration of rhGH alone altered the plasma steroid distribution, and the results demonstrated significantly increased concentrations of plasma estrone as well as decreased concentrations of testosterone and androstenedione in the ND-treated rats. Administration of rhGH to ND-pretreated rats did not reverse the alteration of the steroid distribution induced by ND. Administration of ND decreased the weight of the thymus, and addition of rhGH did not reverse this reduction. However, rhGH administration induced an enlargement of thymus. Taken together, the plasma steroid profile differed in the four groups, . control, AAS, rhGH and the combination of AAS and rhGH treatment.

In order to investigate the in vitro steroidogenic capacity of glands at different ages, minces of testicular tissue were incubated with labelled precursors. The studies were conducted in triplicate at 35°C. For equal quantities of incubated tissue the non-metabolized amount of [ 3 H]pregnenolone and [ 14 C]progesterone, utilized as precursors, was different in post-pubertal and senescent animals: ± 3 vs ± % ( P < ) for pregnenolone, and ± vs ± % ( P < ) for progesterone, respectively. Testosterone production was 12 ± 2% in adult and ± % in senescent animals ( P < ). The testosterone/ androstenedione ratio was not significently different in post-pubertal and senescent animals: ± vs ± , but consistently higher than found in immature animals: ± . The lesser potential capacity of the aging tissue to synthesize testosterone could be explained by a decline in the glands capacity to metabolize the hormonal precursors.

Biosintesis de esteroides en el ovario

biosintesis de esteroides en el ovario


biosintesis de esteroides en el ovariobiosintesis de esteroides en el ovariobiosintesis de esteroides en el ovariobiosintesis de esteroides en el ovariobiosintesis de esteroides en el ovario