Effects of Prostaglandins and Indomethacin on the Response of Rat Testis to LH in vivo

Abstract

In adult male rats, bilateral intratesticular administration of 20 μg PGA1 or 20 μg indomethacin significantly reduced the acute stimulation of plasma testosterone levels by concomitantly injected LH, while treatment with the same dose of PGF2α was without effect. After six days of treatment with indomethacin, plasma testosterone levels were reduced to approximately 1/3 of the control levels. Intratesticular administration of 10 μg LH per testis per day produced, after six days, a precipitous decline in plasma testosterone levels and a decrease in the weight of the testes. This was probably due to desensitization of Leydig cells by these high doses of gonadotropin. Administration of PGF2α together with LH caused a further decrease in testicular weight and a significant reduction in the weights of the prostate and the seminal vesicles.