Nitric oxide and vasoactive intestinal polypeptide mediate non-adrenergic, non-cholinergic inhibitory transmission to smooth muscle of the rat gastric fundus

LC Guang, MJ Rand - European journal of pharmacology, 1990 - Elsevier
LC Guang, MJ Rand
European journal of pharmacology, 1990Elsevier
The nitric oxide (NO) synthesis inhibitor N G-monomethyl L-arginine (L-NMMA) reduced
NANC-mediated relaxations of isolated strips of the rat gastric fundus elicited by low
frequencies or shcrt periods of field stimulation, but D-NMMA had no effect. The inhibitory
effect of L-NMMA on NANC-mediated relaxations was partially reversed by L-arginine but
was not affected by D-arginine. A VIP antibody abolished the relaxant response to VIP and
reduced the responses to stimulation. Residual responses to stimulation in the presence of …
Abstract
The nitric oxide (NO) synthesis inhibitor NG-monomethyl L-arginine (L-NMMA) reduced NANC-mediated relaxations of isolated strips of the rat gastric fundus elicited by low frequencies or shcrt periods of field stimulation, but D-NMMA had no effect. The inhibitory effect of L-NMMA on NANC-mediated relaxations was partially reversed by L-arginine but was not affected by D-arginine. A VIP antibody abolished the relaxant response to VIP and reduced the responses to stimulation. Residual responses to stimulation in the presence of VIP antibody were further reduced by L-NMMA. The tone of the fundus strip was slightly increased by L-NMMA and slightly reduced by L-arginine. The relaxation produced by VIP was slightly reduced by L-NMMA and enhanced by L-arginine. Relaxations produced by peptide histidine isoleucine, sodium nitroprusside or isoprenaline were not affected by L-NMMA or L-arginine. The results suggest that NO as well as VIP is involved in NANC-mediated relaxations of the rat gastric fundus.
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