Production of seminiferous and interstitial fluid in the growing rat after unilateral testicular irradiation

The production of tubular fluid (TF) and interstitial fluid (IF) in normal and irradiated testes was compared in the same growing rats submitted at 25 days of age to unilateral, scrotal X-ray, exposure. Twelve rats were sacrificed each week from 32 to 81 days of age. In both normal and irradiated testes, IF increased in parallel with the testicular weight until 67 days of age and declined slightly thereafter. TF secretion of normal testes increased significantly until 53 days of age, declined significantly until 67 days, and stabilized thereafter. A similar pattern of TF secretion was observed for irradiated testes but with a greater production between days 32 and 46, a lower maximal level at day 53 and a lower but non-significant level from day 67 onwards. All these observations combined with previous results led us to suggest (1) the quantitative influence of germ cells on both TF and IF secretion, (2) the stimulatory effect of diploid germ cells (spermatogonia) and (3) the inhibitory effect of haploid germ cells (probably spermatids) on Sertoli cell secretion. The latter qualitative influence seemed preponderant in adulthood.