Nitric oxide synthase/nitric oxide pathway mediates intussusception pathogenesis in rats

Objective To study the role of nitric oxide synthase/ nitric oxide pathway in the pathophysiological process of intussusception (IN). Methods The IN model of rat was induced by lipopolysaccharide (LPS). The co ntent of NOx in plasma and the NOS activity in colic smooth muscle tissues were measured. The content of cGMP was determined by radioimmunoassay. Results LPS (10 mg/kg, ip) induced IN in up to 40% of the rats 6 hours afte r treatment with LPS. The incidence of IN was significantly increased by 58 .3% (P< 0.05) and by 66.8% ( P < 0.01) in L-arginine (L-Arg)-treated rats ( 2% in drinking water) and in sodium nitroprusside (NSP)-treated rats (1 mg/ kg, ip), respectively, but it is significantly decreased by 66.8% (P<0.01) after administration of M-omega-nitro-L-arginine methyl ester(L-NAME,15 mg/ kg, ip), an inhibitor of nitric oxide synthase (NOS) activity. Furthermore, LPS increased total NOS activity, NOx production and cGMP levels in plasma or in colic smooth muscle tissues. These parameters in LPS-IN rats were si gnificantly elevated by 38.8%, 50.7%, and 48.7% respectively (P < 0.01) com pared with LPS-non-IN rats. Conclusion NOS/NO pathway plays an important role in the process of IN, and inhibition of NO production may serve as a possible approach to prevent IN .