L-精氨酸、L-硝基精氨酸对红藻氨酸诱导大鼠癫痫及其海马结构中iNOS mRNA表达的影响

目的　观察诱导型一氧化氮合酶 (iNOS)在红藻氨酸(KA)癫痫大鼠海马内的表达及L 精氨酸 (L Arg)和L 硝基精氨酸 (L NNA)慢性干预的影响。方法　采用惊厥剂量的KA(1 0mg·kg- 1 )诱导大鼠癫痫发作 ,以NOS抑制剂L NNA(50mg·kg- 1 )和NO前体L Arg(40mg·kg- 1 )进行干预 ,对大鼠的癫痫发作行为及KA后不同时间点的海马内i NOSmRNA ,通过RT PCR观察其表达。结果　KA可使动物发生时间相关性癫痫发作 ,L NNA预处理后使KA诱导的癫痫发作明显加重 ,而L Arg预处理后使KA诱导的癫痫发作减弱。iNOSmRNA在KA处理后 3h开始有微弱的表达 ,且随着时间的延长逐渐增加 ,2 4h达到最高水平 ,2d及3d时未见表达 ,但 7d时又出现高表达 ;经L NNA预处理的动物 ,KA后 1h其海马结构中未出现iNOSmRNA ,但L Arg预处理后再给予KA后 1h ,可见微弱的iNOSmRNA表达。结论　红藻氨酸给药后一定时间 ,癫痫大鼠海马结构中可出现iNOSmRNA表达 ,L Arg慢性干预也有一定影响

Effect of L-arginine or L-nitroarginine on kainic acid induced seizure and expression of iNOS mRNA in the rats'' hippocampus

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.