EPIDIDYMAL MATURATION OF CHROMATIN IN SPERMATOZOA FROM CONTROL MONKEYS (MACACA-FASCICULARIS) AND THOSE TREATED WITH CETRORELIX, A GONADOTROPIN-RELEASING-HORMONE ANTAGONIST

In order to examine changes in sperm chromatin upon epididymal maturat ion in the macaque epididymis (Macaca fascicularis), spermatozoa were obtained from six regions of the duct and examined for the state of th eir chromatin condensation by flow cytometry after staining with acrid ine orange. To see whether changes were affected by androgens, tissue was obtained from five monkeys treated with the gonadotropin releasing hormone (GnRH) antagonist Cetrorelix. Spermatozoa were recovered from treated and control animals after 16 days (at hemicastration) and ano ther 9 days of treatment. Chromatin condensation of epididymal spermat ozoa from controls displayed an increase upon maturation. After 16 day s of GnRH-antagonist treatment, spermatozoa in the caput epididymidis displayed greater fluorescence than those from controls, but this was reduced during epididymal transit to values found in the distal epidid ymal regions of the controls. It is concluded that epididymal chromati n condensation 1) is normal in GnRH-antagonist-treated monkeys as long as sperm are being produced and 2) can compensate for poor testis fun ction so that spermatozoa with normal states of chromatin condensation are found in the distal cauda epididymidis and probably the ejaculate .