补硒对低硒居民血小板活化状态的影响

应用１２５Ｉ标记放免法测定血浆血栓素（ＴＸＡ２）、前列环素（ＰＧＩ２）和血小板ＴＸＡ２生成，以比浊法和ＥＬＩＳＡ分别测定血小板聚集性和β－血小板球蛋白（βＴＧ），电镜观察血小板形态，对比研究补硒（２００μｇＳｅ／ｄ，亚硒酸钠，１２周）和未补硒低硒居民上述参数的变化。用２，３－二氨基萘荧光法和谷胱甘肽还原酶偶联法测定硒含量和谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）活性。结果表明，补硒使红细胞硒和ＧＳＨ－Ｐｘ活性显著增高（Ｐ＜０．０１）；血浆ＴＸＡ２、ＴＸＡ２／ＰＧＩ２比值及血小板ＴＸＡ２生成和聚集性均显著低于未补硒组（Ｐ＜０．０１或０．０５），但血浆ＰＧＩ２和βＴＧ含量以及血小板βＴＧ含量和释放率无显著改变（Ｐ＞０．０５）；补硒可明显减轻病区低硒居民血小板的形态变化，使α－颗粒数显著高于未补硒组（Ｐ＜０．０１）；红细胞硒或ＧＳＨ－Ｐｘ活性分别与血浆ＴＸＡ２和血小板ＴＸＡ２生成呈显著负相关（ｒ＝－０．６９６，－０．７８０；－０．６７６和－０．７９６，Ｐ＜０．０１），与ＡＤＰ诱导的血小板聚集性显著负相关（ｒ＝－０．３９０，－０．３７２，Ｐ＜０．０５）；与凝血酶诱导的聚集性呈不显著的负相关（ｒ＝－０．２７９，－０．３０９?

EFFECTS OF SELENIUM SUPPLEMENTATION ON PLATELET ACTIVATION OF RESIDENTS WITH LOW SELENIUM STATUS

To evaluate the influences of selenium supplementation on platelet activation of residents in a low selenium Keshan disease area,plasma thromboxane A 2 (TXA 2) and prostacyclin(PGI 2),platelet TXA 2 formation,aggregation,β thromboglobulin(βTG) and morphology were investigated in slenium supplemented(200μg Se/d,as sodium selenite for 12 wk)and unsupplemented residents in the endemic area by using 125 I labelled radioimmunoassay,turbidimetry,ELISA and electronmicroscope respectively.Selenium contents were measured by 2,3 diaminonaphthalene fluorospectrometry and glutathione peroxidase (GSH Px)activity by GSH reductase coupled method.The results showed that:(1)Selenium supplementation resulted in significant increases in erythrocyte selenium contents and GSH Px activiy as compared with the placebo group;(2)Plasma TXA 2 and TXA 2/PGI 2 ratio,platelet TXA 2 formation and aggregation were significantly lower in the selenium supplemented group than in the control,but no remarkable differences in plasma PGI 2 and βTG,platelet βTG and the release of βTG were observed between the two groups;(3)Selenium supplementation could apparently moderate the morphological changes of platelets in residents from the low selenium endemic area,and the number of α granuales was significantly higher in the supplemented group than in the control;(4)Significant negative correlations between erythrocyte selenium or GSH Px activities and plasma TXA 2,ADP induced platelet TXA 2 formation or platelet aggregation,as well as insignificant negative correlations between erythrocyte selenium contents or GSH Px activity and thrombin induced platelet aggregation were obtained.The investigation suggests that one of the mechanisms for the preventive effect of selenium supplementation on the incidence of Keshan disease might lie in alleviating the higher platelet activation of residents in the endemic area,thus eliminating the basis for occurrence of the perivascular necroses in myocardium.