Substance P- and Vasoactive Intestinal Peptide-Containing Fibers Reach the Ovary by Independent Routes*

Abstract

The immature rat ovary is innervated by both substance P (SP)- and vasoactive intestinal peptide (VIP)-containing nerve fibers. To determine the origin of these fibers, juvenile rats were sham operated or subjected to transection of the abdominal vagus nerves, superior ovarian nerves, or ovarian plexus nerves or to concomitant transection of the vagal and superior ovarian nerves. Specific immunofluorescent staining of ovarian sections for SP and VIP revealed that VIP innervation to the ovary occurs only via the superior ovarian nerves, whereas ovarian SP innervation is exclusively via the plexus nerves. Thus, specific SP and VIP nerves reach the gland via anatomically different routes. The results indicate that autonomic regulation of ovarian function may be exerted via independent peptidergic neural pathways.