左旋精氨酸对被动吸烟孕鼠及胎仔发育的作用及其与NO、NOS的关系

目的了解左旋精氨酸对被动吸烟所致大鼠宫内发育迟缓及胎仔生长发育的作用,通过其与NO、NOS的关系探讨其作用机理.方法利用被动吸烟法建立大鼠IUGR模型,孕鼠随机分为5组:对照组、模型组、低剂量左旋精氨酸组、中剂量左旋精氨酸组、高剂量左旋精氨酸组.孕21天剖宫取胎,观察胎盘重、仔重、仔脑重、仔肝重;检测孕鼠血清及胎盘组织中NO含量及iNOS、cNOS活性.结果与对照组比较,模型组孕鼠胎盘重及仔重、仔脑重、仔肝重均明显降低(P<0.01),孕鼠血清及胎盘组织NO含量下降,iNOS活性升高,cNOS活性下降(P<0.01).低剂量及中剂量左旋精氨酸组与模型组比较各指标均有改善,但高剂量左旋精氨酸组与模型组比较无明显差异.结论孕中期应用一定剂量左旋精氨酸可有效防治被动吸烟孕鼠IUGR的发生并对胎仔发育有显著促进与保护作用,其作用与NO/NOS系统有关系.

The effect of L-arginine on passive smoking induced IUGR rats and fetal rats and NO/NOS system

Objective: To explore the effects of L-arginine on passive smoking rats and fetal rats with IUGR. Methods: After establishment of IUGR model with passive smoking, rats were divided randomly into 5 groups: normal control group, IUGR group, low dose of L-arginine treated group, middle dose of L-arginine treated group and high dose of L-arginine treated group. The body weight, brain weight and liver weight of fetal rats and the placenta weight were examined. The levels of NO, iNOS and cNOS activity in the serum and placentas were measured. Results: The average body weight, brain weight and liver weight of fetal rats and the average placenta weight of IUGR group were significantly lower than those of control. The levels of NO and cNOS activity in the serum and placentas of IUGR rats were decreased significantly, but the activity of iNOS was increased. All of these changes were improved in low and middle doses of L-arginine treatment groups. But no statistical difference was observed between high dose of L-arginine treatment group and IUGR group. Conclusions: L-arginine can decrease the incidence of IUGR in rats of passive smoking and improve the development of fetal rats. But high dose of L-arginine should be carefully used.