L—精氨酸对急性缺氧大鼠血浆NO和ET含量变化的影响

目的 为了研究外源性L-精氨酸（L-Arg）对急性缺氧大鼠血浆一氧化氮（NO）和内皮素（ET）含量变化的影响。方法 采用组织化学方法，生化Griess法和放射免疫法分别测定大鼠肺血管内膜一氧化氮合酶（NOS）活性，血浆NO、ET和环腺苷酸（cGMP）含量水平。结果 （1）急性缺氧1h后血浆NO和cGMP含量水平下降，血浆ET含量水平上升，肺血管内膜NOS活性下降。（2）L-Arg干预后血浆NO和cGMP 含量水平较缺氧组明显增加，血浆ET含量水平则明显下降，而局部肺血管内膜NOS活性较缺氧组无显著差异。结论 急性缺氧能导致血浆NO含量水平下降，血浆ET水平升高，肺血管内膜NOS活性下降。应用外源性L-Arg干预急性缺氧可使下降NO水平升高。血浆ET水平下降，从而推测L-Arg有缓解缺氧毒性及缓解性肺动脉高压的作用，故临床上运用L-Arg可望对某些疾病具有有益的治疗作用。

Effect of L-arginine Therapy on Serum Nitric Oxide and Endothelin in Acute Hypoxic Rat

Purpose To study the changes of serum nitric oxide(NO)and endothelin(ET)levels by L?Arg therapy in acute hypoxic model. Methods NADPH diaphorase histochemical staining method,Griess biochemical assay and radioimmune assay were applied to investigate the changes of nitric oxide synthase(NOS),NO,cGMP and ET in normal,hypoxic and L?Arg treated hypoxic rats. Results during acute hypoxia,while serum ET rose up significantly,both the levels of serum NO and cGMP and the activity of NOS were significantly lower.After the application of L?Arg therapy,the activity of NOS did not change significantly,but the levels of serum NO and cGMP rose up significantly,and the level of serum ET was to the opposite direction. Conclusions NO and ET may modulate hypoxic pulmonary hypertension,and acute hypoxia can result in acute hypoxic pulmonary hypertension.L?Arg can reverse the acute hypoxic hypertension.