【摘要】 在超氧阴离子（Ｏ^－_２）作用下，心肌细胞内游离钙浓度(［Ｃａ^２＋］_ｉ)显著升高；心肌细胞膜通透性明显增强；膜脂流动性下降。一定浓度的硒代蛋氨酸（Ｓｅ－Ｍｅｔ）或亚硒酸钠（Ｎａ_２ＳｅＯ_３）可不同程度地拮抗Ｏ^－_２的影响。前者作用更为显著。这两种硒化合物也能提高谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）的活性。综上所述，硒缺乏，高自由基及心肌细胞Ｃａ^２＋平衡失调三者之间存在着相关性。在Ｏ^－_２作用下，心肌细胞内Ｃａ^２＋平衡失调比膜通透性的改变更为敏感。更多还原

【Abstract】 Under the action of O￣-₂, Ca￣（2+）concentration （[Ca￣（2+）₁]i） and membrane permeability of myocardial cells were markedly increased, while the lipid fluidity was decreased. Such change can be antagonized mostly by 1.0 μmol/L selenium methionine （Se-Met） or partly by 2.3 μmol/L Na2SeO3. The O-2 chemiluminescence signal intensity could be significantly quenched by Se-Met or Na2SeO3, but the effect of the former is stronger than the latter. Activity of glutathione peroxidase （GSH-Px） was also increased by both of the Se-containing compounds. There seems to be some interrelationship between Se deficiency, higher active oxygen radicals and the change of Ca￣（2+） homeostasis in the myocardial cells. The change of Ca￣（2+） homeostasis is more sensitive than that of membrane permibility in response to the action of O-2 injury.更多还原