Vasoactive intestinal polypeptide occurs in nerves of the female genitourinary tract.

The vasoactive intestinal polypeptide occurs in a richly developed population of nerves that are abundant in the female genitourinary tract. In pigs, cats, rats, and mice these nerves seem to innervate vessels and smooth musculature. Evidence indicates that vasoactive intestinal polypeptide represents a peptide neurotransmitter. Its effects on uterine blood flow and contractility, for example, may be considerable.