Changes in testicular fluid production and plasma hormones in the adult rat after testicular 60Co irradiation.

Adult Wistar rats exposed to testicular radiocobalt irradiation (0.8 Gy) were alloted to four groups: sham control, protected control, unilaterally irradiated and bilaterally irradiated. The rats of each group were killed 30, 45, 60, 75 and 105 days after gamma-ray exposure and/or general anaesthesia. Tubular fluid (TF) production, estimated by ligature of the efferent ducts of both unilaterally and bilaterally irradiated testes, 24h prior to sacrifice, was transiently increased 30 and 45 days after irradiation (P less than 0.001); there was no increment in the interstitial fluid (or lymph) collected compared to sham and protected control testes. At 30 and 45 days, irradiated testis weight decreased significantly. From 60 to 105 days after gamma-ray exposure, TF gradually returned to control levels, while the testicular weight increased. The plasma FSH, LH, PRL and testosterone of the irradiated rats did not change significantly compared to the controls. Consequently, it is presumed that TF secretion was regulated locally by a germ cell-Sertoli cell interrelationship.