低硒对大鼠血管一氧化氮合酶和微循环的影响

采用低硒饲料饲养大鼠造成体内贫硒。１４周时测定血浆中脂质过氧化物（ＬＰＯ）、前列环素（ＰＧＩ２）和血栓素（ＴＸＡ２）的水平以及部分血液流变学指标。实验第３９周，测定血管组织一氧化氮合酶（ＮＯＳ）活性及一氧化氮（ＮＯ）水平。结果显示，低硒饲料组的血管ＮＯＳ活性、ＮＯ水平显著低于常规饲料的对照组；而在实验第１４周时，当低硒饲料组的血硒、血谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性显著下降、血浆ＬＰＯ水平明显上升的同时，其对应的血浆６－酮－ＰＧＦ１α水平也显著降低，但其ＴＸＢ２与对照组无显著差异。此外，随着大鼠体内的贫硒，其红细胞变形能力下降，但红细胞聚集指数和血沉方程Ｋ值提高。因此，硒不足可能会通过影响ＮＯＳ活性和ＰＧＩ２的合成以及红细胞特性而损害微循环功能。

Effects of Selenium Deficiency on Vascular Nitric Oxide Syntheses and Microcirculation of Rats

Weanling male Wistar rats were fed with Se-deficient diet (containing Se 0022 mgkg1) and stock diet (containing Se 0326 mgkg1 control group) ,respevtively. 6-keto-PGF1,TA2 and some hemorheological parameters of rats at the 14th week, the vascular NOS and NO at the 39th week were respectively determined.The results showed that plasma 6-keto-PGF1 level, vascular NOS activity and NO content in Se-deficient rats were significantly lower than those in control group. Meanwhile, Se content and glutathione peroxides activity in blood and vascular of Se-deficient rats decreased significantly, whereas lipid peroxides level in their plasma and vascular increased markedly. Furthermore, erythrocyte deferability decreased,but erythrocyte aggregation index and reythrocyte sedimentation K increased in Se deficient group. However,there were no remarkable differences in plasma viscosity,hematocrit,erythrocyte electrophoresis index,plasma fibrinogen and TXB2 level between Se deficient rats and control group. The above suggested that Se deficiency may have harmful effects no microcirculation through changing NOS activity prostacyclin synthesis and some erythocyte parameters.