Effect of an LH-RH analog on cat testis and adrenal cortex function.
The LH-RH analog LH-RH-A (des-Gly10,[D-Trp6]-LH-RH ethylamide) was administered in pharmacological doses (20 micrograms/kg, sc) to adult male cats for 15 days and its effect on testis and adrenal function was determined. Daily administration of the analog promoted a 3-fold increase in plasma testosterone levels after 7 days, indicating a stimulatory effect of LH-RH-A (mean +/- SD for 6 treated cats, 1.88 +/- 0.35 vs 0.51 +/- 0.08 ng/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 +/- SD, 0.96 +/- 0.35 ng/ml vs 0.88 +/- 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 +/- SD of index of accumulation was 3.50 +/- 0.4 for treated cats vs 2.20 +/- 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.
Rosa-e-Silva
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AA
Departamento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.
Lamano-Carvalho
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TL
Queiroz
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AN
D000302:Adrenal Cortex / Q000033:anatomy & histology / Q000502:physiology*; D000818:Animals; D001835:Body Weight; D002415:Cats; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009929:Organ Size; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000033:anatomy & histology / Q000502:physiology*; D013739:Testosterone / Q000097:blood*; D017329:Triptorelin Pamoate / Q000031:analogs & derivatives*
D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; C019176:Tryptal