Sympathetic efferent pathways projecting bilaterally to the vas deferens in the rat.

BACKGROUND

The laterality of the signals passing through the splanchnic 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 splanchnic nerves (LSN) following consecutive transections of more distal nerves.

RESULTS

L2-L6 LSN stimulation increased VP bilaterally. Left VP responses decreased slightly (< 20%) after section of the right hypogastric nerve (HGN) and then were abolished by subsequent section of 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 commissural 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 and then abolished by section of the right B-M-APG. These responses were also decreased by > 70% by section of right HGN, not changed by section of CB-MPG, but then completely eliminated by section of CB-APG.

CONCLUSIONS

These results indicate that the left lumbar sympathetic pathway to the vas deferens is distributed bilaterally and exhibits two crossing points at the level of the inferior mesenteric ganglion and APG.