Effect of intrathecal injection of ?-conopeptide SO3 on inducible nitric oxide synthase expression in spinal cord and chronically constricted sciatic nerve in rat / 解放军医学杂志

ABSTRACT

Objective To evaluate the effect of intrathecal administration of ?-conopeptide SO3 on inducible nitric oxide synthase(iNOS)expression of spinal cord and the ligated sciatic nerve in a rat model with chronic constriction injury(CCI).Methods 40 male SD rats were randomly divided into 4 groups of 10 animals each.Rats in the N group served as controls;in group C 4 loose ligatures were placed around the right sciatic nerve for 14 days;in group CN,normal saline 1?l/h was injected intrathecally slowly for 7 days seven days after the ligation;in group CS,?-conopeptide SO3 30ng/h was administered intrathecally slowly for 7 days seven days after the ligature.Local expression of iNOS was assayed in samples taken from injured nerves(between and distal to the CCI site)and the spinal cord using Western blotting analysis,with GAPDH as an internal reference.Results A 130 kDa band,corresponding to iNOS protein was detected in the middle and distal sections of the injured nerves and the spinal cord.The iNOS immunoreactivity was inhibited by continuous intrathecal injection of ?-conopeptide SO3.There was no difference in the expression of iNOS between group CN and group C.Conclusion The expression of iNOS in the spinal cord and injured nerves of CCI rats was enhanced.Intrathecal injection of ?-conopeptide SO3 can inhibit the expression of iNOS.The data suggested that N-type calcium channel blocker took part in the expression of iNOS.