Postvasectomy alterations in protein synthesis and secretion in the rat caput epididymidis are not repaired after vasovasostomy

Many men who have undergone vasectomy later request vasovasostomy. Unfortun ately, significant numbers of these men remain infertile despite the reesta blishment of patent ducts. This report examines the possibility that epidid ymal function remains compromised after vasovasostomy in the rat by examina tion of quantifiable, in vivo protein synthesis and secretion in the caput epididymidis. Rats were studied 30 days after vasectomy, 30 days after a va sovasostomy (which was performed 30 days after vasectomy), or after sham op erations. Epididymal lumen fluids (LF) were collected by micropuncture afte r 3 hours' in vivo microperifusion of tubules with S-35-amino acids. Protei ns were separated by 2-dimensional electrophoresis and were detected by Coo massie blue staining. Synthesized proteins in tubule extract and synthesize d and secreted proteins in LF were detected by autoradiography and image an alysis. Specific proteins that appeared to be affected by vasectomy-vasovas ostomy were identified by internal sequence analysis. LF contained an avera ge of 87 detectable proteins synthesized and secreted in the control caput. Nineteen of the most prominent LF proteins were selected for more focused study. The most prominent proteins were clusterin, cysteine-rich secretory protein (CRISP)-1, and epididymal retinoic acid-binding protein. Among thes e, CRISP-1 remained reduced in LF after vasovasostomy. Two more minor prote ins that remained reduced after vasovasostomy were identified as prostaglan din D-2 synthase and phosphatidylethanolamine-binding protein. All 3 of the se proteins occur in the epididymides of multiple species and have been ass ociated with sperm fertilizing capacity.