ESTIMATE OF EPIDIDYMAL TRANSIT-TIME IN THE CHIMPANZEE

During their passage through the epididymis, sperm undergo functional changes which result in their maturation and in their ability to ferti lize ova. Maturational changes effected during epididymal transport ar e attributable to sequential changes in various regions of the plasmal emma of the sperm head and flagella, These functional changes in the p lasmalemma result, at least in part, from the sequential binding of pr oteins secreted by the epididymal epithelium into the epididymal lumen . An estimate of epididymal transit time is essential to such investig ations. Time elapsed from a testicular arterial infusion of a single p ulse of tritiated-thymidine to the release of H-3-labeled sperm into t he lumen of the seminiferous tubule was about 39 days. Seminal fluid-f ree H-3-labeled sperm first appear in the ejaculate about 41+/-1 days post-infusion. Total transit time for H-3-labeled Sd2 sperm released i nto the tubular lumen to appear in the ejaculate is estimated as the d ifference between these values, Since total transit time is equal to t he seminiferous tubule transit time plus the epididymal transit time, epididymal transit time constitutes some lesser portion of the total t ransit time of 2+/-1 days.