Vasoactive intestinal peptide modulates T lymphocyte migration in Peyer's patches of rat small intestine

The Peyers patches of rat small intestines were analyzed by intravital microscope and fluorochrome carboxyfluorescein diacetate succinimidyl ester (CFDASE) to determine the dynamics of intestinal T lymphocyte migration. CFDASE analysis of rat ileal Peyers patches indicated the inhibitory role of vasoactive intestinal polypeptides (VIP) on the transendothelial migration of T lymphocytes through the ileal postcapillary venules. Furthermore, VIP-induced attenuation of ileal T cell migration involves the relaxation of vascular smooth muscles which alters the permeability of the capillaries.