红藻氨酸致癫痫大鼠脑内一氧化氮合酶的动态表达研究

目的探讨一氧化氮合酶（NOS）的三种不同亚型nNOS、iNOS、eNOS在红藻氨酸（KA）了致癫痫SD大鼠模型中不同部位和不同时间的变化情况。方法KA点燃癫痫SD大鼠，随机分为对照组、KA组，在致痫1、7、14、21和28d各个时间点，观察大鼠癫痫发作后的行为学变化，脑电图描记，采用免疫组化的方法研究三种不同NOS（nNOS、iNOS和eNOS）的表达。结果注射KA后大鼠出现癫痫发作，7～28d可见癫痫慢性自发发作。EEG表现为尖、棘波节律，7～28d仍可见痫性活动。KA致痫后1d，nNOS在CA1、CA2、CA3区表达较对照组明显增多，7d时开始出现下降，在cA2、CA3区14d后又出现增多，在颞叶从1d开始就持续高水平的表达，而在齿状回和丘脑不同时间点nNOS阳性细胞表达都很低。iNOS在1d时各区表达均较对照组增高，之后在CA1、CA2、CA3区及颞叶阳性细胞出现减少，而在齿状回及丘脑7、14d有所下降，之后又出现高表达。eNOS在KA致痫后1d在CA1、CA2及齿状回区表达较对照组增高，7d时出现下降，之后叉出现增多，但eNOS阳性细胞在CA3区却表现为癫痫发作后1、7d时出现少，在14d以后才大量出现，并逐渐增加，在颞叶及丘脑，1d时与对照组无明显差异，7d时才开始表达增高，并持续高表达至28d。结论KA诱导癫痫发作大鼠脑内不同类型NOS在不同的时间和部位表达不同。

A study of NOS expression in rats after kainic acid-induced seizures

Objective To explore the changes of three different subtypes of NOS,named nNOS,iNOS and eNOS of kainic acid(KA)-induced SD rats in different parts and different time.Methods KA was used to evoke chronic epilepsy model.The SD rats were randomly divided into control groups,KA groups.The KA groups were also divided into five sub-groups(1,7,14,21,28 days) according to seizure attack at the different time-point.Ethology changes and electroencephalography were observed after epileptic seizure,expressions of nNOS,iNOS and eNOS were investigated with immunohistochemical method.Results Seizures were observed immediately after administration of KA,chronic spontaneous seizures were observed since 7th day.EEG showed continual sharp and spike waves at difference time points.nNOS increased at CA1,CA2 and CA3 after 1 day,reduced after 7 days,and increased at CA2 and CA3 after 14 days.High expressions of nNOS were observed at temporal lobe since first day.Expressions of nNOS were in a low level at dentate gyrus and thalamencephal.iNOS increased in all regions after 1 day,dropped down to the normal level at CA1,CA2,CA3 and temporal lobe since 7th day,but continued to increase at dentate gyrus and thalamencephal after 21 days.eNOS increased at CA1,CA2 and dentate gyrus since the first day,dropped to the normal level after 7 days,continued to increase after 14 days,but eNOS was in a low level after 1 day and 7 days,increased to a high level after 14 days.eNOS was in a normal level at temporal lobe and thalamencephal after 1 day,but increased to a high level after 7 days.Conclusion Expressions of different subtypes of NOS in rats after kainic acid-induced Seizures were different at different time and different area.