Effect of L-arginine or L-nitroarginine on kainic acid induced seizure and expression of iNOS mRNA in the rats' hippocampus / 中国药理学通报

ABSTRACT

AIM To observe the expression of inducible nitric ox ide synthase (iNOS) in the rats' hippocampus of kainic acid (KA) induced-seizur es and the effect of L-arginine(L-Arg) or L-nitroarginine(L- NNA) chronic intervention before KA. METHODS The expression of iN OS mRNA by RT-PCR and behaviour were observed after administration of convulsan t dose of KA (10 mg?kg -1 ) and pretreatment with NO predecessor (L-Ar g, 40 mg?kg -1 ) or a inhibitor of NOS(L-NNA, 50 mg?kg -1 ) befo re KA. RESULTS The time-dependent seizures were induced on rats after giving KA, and were improved and serious in the animals with L-NNA pr etreatment, but they were alleviated by L-Arg pretreatment before KA. Compa red with control, iNOS mRNA expression was feebly at KA 3 h, continuative improv ement accompanying KA time prolonged, and it was markedly enhanced at KA 24 h. I t couldn't be examined at KA 2 d or 3 d, and was obviously improved at KA 7 d a gain. iNOS mRNA appeared weak in the rats hippocampus with L-Arg pretreatme nt after KA 1 h, whereas it wasn't found in L-NNA pretreatment animals. CONCLUSION iNOS mRNA expression appeared in the hippocampus of seizu re rats at a few time after KA, and L-Arg chronic intervention before KA ha s a little effect on it.