SYMPATHETIC EFFERENT PATHWAYS PROJECTING BILATERALLY TO THE VAS-DEFERENS IN THE RAT

Background: The laterality of the signals passing through the splanchn ic nerves to the vas deferens has not been well studied. Methods: The present study was designed to determine the bilateral distribution of sympathetic nerves to the rat vasa deferentia by measuring intravasal pressure (VP) responses to electrical stimulation of left lumbar splan chnic nerves (LSN) following consecutive transections of more distal n erves. Results: L-2-L-6 LSN stimulation increased VP bilaterally, Left . VP responses decreased slightly (< 20%) after section of the right h ypogastric nerve (HGN) and then were abolished by subsequent section o f branches (B-M-APG) between the left major pelvic (MPG) and accessory pelvic ganglia (APG), Left VP responses were decreased by > 80% after section of left HGN, not changed further by subsequent section of com missural branches (CB-MPG) between the MPG, and completely eliminated by section of commissural branches between the APG (CB-APG). Right VP responses were decreased slightly (< 20%) by section of the left HGN a nd then abolished by section of the right B-M-APG. These responses wer e also decreased by > 70% by section of right HGN, not changed by sect ion of CB-MPG, but then completely eliminated by section of CB-APG. Co nclusions: These results indicate that the left lumbar sympathetic pat hway to the vas deferens is distributed bilaterally and exhibits two c rossing points at the level of the inferior mesenteric ganglion and AP G. (C) 1997 Wiley-Liss, Inc.