Role of VIP and Substance P in NANC Innervation in the Longitudinal Smooth Muscle of the Rat Jejunum—Influence of Extrinsic Denervation

• Published in: The Journal of surgical research Vol. 141; no. 1; pp. 22 - 30
• Main Authors: Kasparek, Michael S., M.D, Fatima, Javairiah, M.D, Iqbal, Corey W., M.D, Duenes, Judith A., B.A, Sarr, Michael G., M.D
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY Elsevier Inc 01-07-2007; Elsevier
• Subjects: Adrenergic Fibers - physiology; Animals; Biological and medical sciences; Cholinergic Fibers - physiology; Electric Stimulation; enteric nervous system; extrinsic innervation; Gastrointestinal Motility - physiology; General aspects; Jejunum - innervation; Jejunum - transplantation; Male; Medical sciences; motility; Muscle Contraction - drug effects; Muscle Contraction - physiology; Muscle, Smooth - innervation; Nitroarginine - pharmacology; nonadrenergic noncholinergic innervation; Organ Transplantation; Rats; Rats, Inbred Lew; small intestinal transplantation; small intestine; Substance P; Substance P - physiology; Surgery; Synaptic Transmission - physiology; Vasoactive Intestinal Peptide - physiology; Vasoactive Intestinal Polypeptide; extrinsic innervation; small intestinal transplantation; Vasoactive Intestinal Polypeptide; Substance P; motility; small intestine; enteric nervous system; nonadrenergic noncholinergic innervation; Motility; Rat; Innervation; Smooth muscle; Nervous system; Transplantation; Small intestine; Jejunum; Surgery; Graft; Rodentia; Medicine; Vertebrata; Mammalia; Treatment; Polypeptide; Animal; Vasoactive intestinal peptide; Denervation
• ISSN: 0022-4804; 1095-8673
• DOI: 10.1016/j.jss.2007.01.021

Background This study was designed to determine changes in nonadrenergic, noncholinergic (NANC) neurotransmission mediated by Vasoactive Intestinal Polypeptide (VIP) and Substance P after small bowel transplantation (SBT). Materials and methods Six groups of rats ( n ≥ 6 per group) were studied: naïve controls (NC); 1 wk after anesthesia/sham celiotomy (SC-1); 1 or 8 wk after jejunal and ileal transection/reanastomosis (TA-1, TA-8), or syngeneic, orthotopic SBT (SBT-1, SBT-8). Jejunal longitudinal muscle strips were studied under NANC-conditions for spontaneous contractile activity, response to exogenous VIP and Substance P, and electrical field stimulation (EFS). Results Spontaneous activity did not differ between the six groups. VIP inhibited contractile activity in all groups 1 wk postoperatively ( P < 0.05), which was prevented by the NO synthase inhibitor L-NG -nitro arginine (L-NNA). In contrast, VIP had no effect in the other groups. Precontraction with Substance P exposed an inhibitory effect of VIP in all groups ( P < 0.05 each). Substance P increased contractile activity in all groups, but to a lesser extent in SBT-8 compared with NC, TA-8, and SBT-1 ( P < 0.05). The inhibitory effect of EFS at 6 Hz was prevented by L-NNA in NC and TA-8; addition of the VIP antagonist ([D-p-Cl-Phe6 , Leu17 ]-VIP) increased contractile activity in NC, but not in TA-8 and SBT-8. The Substance P antagonist ([D-Pro2 , D-Trp7,9 ]-Substance P) decreased contractile activity during EFS at 50 Hz in NC and SBT-8. Conclusions SBT decreased response to exogenous Substance P, although release of endogenous Substance P (EFS) is preserved. Changes in VIP signaling are acute and reversible and not caused by effects of SBT.