ObjectiveTo evaluate the effect of aminoguanidine on expression of inducible nitric oxide synthase (iNOS) in neurons in the small intestinal nerve plexus of starved rats.MethodsNinety male SD rats weighing 230-270 g were randomly divided into 3 groups:group normal control (group C,n =10) ; group starvation (group S,n=40) and group starvation + aminoguanidine (group A,n =40).The animals were allowed free access to water but no food during starvation in S and A groups.In group A the animals were given aminoguanidine 150 mg·kg-1 ·d-1 intraperitoneally during starvation.Ten animals were sacrificed at 3,5,7 and 9 d of starvation respectively and intestine specimens were taken for determination of ratio of intestinal transit using dextran blue-2000 as indicator.Then the specimens of intestinal myenteric nerve plexus of ileum were collected and stained by histochemistry with nicotinamide-adenine dinucleotide phosphate-d for determination of iNOS expression.ResultsStarvation significantly reduced the small intestinal transit and increased iNOS expression in neurons in the myenteric nerve plexus of small intestine in proportion to days of starvation in group S compared with group C.Intraperitoneal aminoguanidine significantly attenuated the starvation-induced changes in intestinal transit and iNOS expression.ConclusionAminoguanidine can attenuate the up-regulation of the expression of iNOS in neurons in the myenteric nerve plexus of small intestine induced by starvation and is helpful in promoting the intestinal transit in starved rats.