【摘要】 包括血管内皮细胞在内的多种细胞和组织存在腺苷三磷酸双磷酸酶（ａｐｙｒａｓｅ） ， 但心内膜内皮细胞是否含有ａｐｙｒａｓｅ 尚无报道。本文旨在研究牛心内膜内皮细胞ａｐｙｒａｓｅ 的特性。以无机磷释放法检测培养牛心内膜内皮细胞（ＢＥＥＣ） ａｐｙｒａｓｅ 的活性。公认的ａｐｙｒａｓｅ 抑制剂叠氮钠呈浓度依赖性地抑制ａｐｙｒａｓｅ 活性； 另一种ａｐｙｒａｓｅ 抑制剂氟化钠（２０ ｍｍｏｌ／Ｌ） 也明显抑制ａｐｙｒａｓｅ 活性。而Ｎａ＋ ／Ｋ＋ＡＴＰａｓｅ 的抑制剂哇巴因（３ ｍｍｏｌ／Ｌ） 却不能抑制该酶活性。ＢＥＥＣａｐｙｒａｓｅ 活性依赖于钙或镁等二价阳离子以及ｐＨ 的改变， ＥＤＴＡ 或ＥＧＴＡ （１ｍｍｏｌ／Ｌ） 均能完全抑制其活性， 在ｐＨ 值为８－５ 时活性最高。由此可见， 牛心内膜内皮细胞存在叠氮钠敏感的、依赖于二价阳离子和ｐＨ 值的腺苷三磷酸双磷酸酶活性。更多还原

【Abstract】 Apyrase activities in some tissues and cells, such as peripheral vascular endothelial cells, have been reported, but these in endocardium endothelial cells have not been reported. The present study was to characterise the properties of bovine endocardium endothelial cells (BEEC) associated apyrase. Apyrase activity was assayed by inorganic phosphate release, which could be inhibited concentration dependently by NaN 3, an apyrase inhibitor. NaF (20 mmol/L), another inhibitor of apyrase, also markedly inhibited the activity. EDTA or EGTA (1 mmol/L) could also inhibit the activity completely. However, the inhibitor for Na +/K + ATPase, ouabain (3 mmol/L) did not affect the enzyme activity. BEEC apyrase activity was dependent on divalent cations (Ca 2+ or Mg 2+ ) and pH value.更多还原