Liu J J, Casley D J, Nayler W G
Department of Medicine, University of Melbourne, Austin Hospital, Heidelberg, Victoria, Australia.
Biochem Biophys Res Commun. 1989 Nov 15;164(3):1220-5. doi: 10.1016/0006-291x(89)91799-3.
Specific, high affinity binding sites for iodinated endothelin-1 ([125I]-ET-1) were identified in crude plasma and light membrane fractions harvested from aerobically perfused and ischaemic rat hearts, to determine whether the ischaemia-induced increase in binding site density (Bmax) involves externalization of the sites. In crude plasma membranes Bmax increased after 60 min ischaemia, from 113.5 +/- 2.15 to 180.6 +/- 4.67 fmol/mg protein (p less than 0.01). In the light membranes, the Bmax fell, from 94.7 +/- 8.70 to 63.80 +/- 6.26 fmol/mg protein (p less than 0.05). Hill coefficients and selectivity of both membrane fractions were unchanged. These results are interpreted as meaning that ischaemia causes externalization of cardiac [125I]-ET-1 binding sites.
在从有氧灌注和缺血大鼠心脏中获取的粗制血浆和轻膜组分中，鉴定出了碘化内皮素-1（[125I]-ET-1）的特异性、高亲和力结合位点，以确定缺血诱导的结合位点密度（Bmax）增加是否涉及这些位点的外化。在粗制质膜中，缺血60分钟后Bmax增加，从113.5±2.15飞摩尔/毫克蛋白质增加到180.6±4.67飞摩尔/毫克蛋白质（p<0.01）。在轻膜中，Bmax下降，从94.7±8.70飞摩尔/毫克蛋白质降至63.80±6.26飞摩尔/毫克蛋白质（p<0.05）。两个膜组分的希尔系数和选择性均未改变。这些结果被解释为缺血导致心脏[125I]-ET-1结合位点的外化。
