Effect of an LH-RH analog on cat testis and adrenal cortex function

RESUMO

The LH-RH analog-LH-RH-A (des-Gly10, [D-Trp6]-LH-RH ethylamide) was administerd in pharmacological doses (20 µg/Kg, sc) to adult male cats for 15 days and its effect on testis and adrenal function was determined. Dayly adminitration of the analog promoted a 3-fold increase in plasma testosterone levels after 7 days, indicating stimulatory effect of LH-RH-A (mean ñ SD for 6 treated cats, 1.88 ñ 0.35 vs 0.51 ñ 0.08ng/ml for 6 control cats). After 15 days the LH-RH-A-treated group exhibited a similar plasma testosterone concentration as the control group (mean ñ SD, 0.96 ñ 0.35 ng/ml vs 0.88 ñ 0.39 ng/ml, respectively), similar testicular and adrenal weights and no significant differences in the spermatogenic process. However, semiquantitative analysis of the zona fasciculata of the adrenals from the LH-RH-A treated group showed a significant accumulation of a substance not stained by hematoxylin-eosin or Schiff periodic acid (mean ñ SD of index of accumulation was 3.50 ñ 0.4 for treated cats vs 2.20 ñ 0.3 for control cats). The present results show that pharmacological doses of LH-RH-A have an effect on the adrenal cortex of cats without modifying spermatogenesis or plasma testosterone levels