Mizuguchi H, Fukui H, Yabumoto M, Wada H
Department of Pharmacology II, Faculty of Medicine, Osaka University, Japan.
Biochem Biophys Res Commun. 1991 Jan 31;174(2):1043-7. doi: 10.1016/0006-291x(91)91524-g.
Localization of histamine H1-receptors in subcellular fractions from rat and guinea pig brains was examined in a [3H]mepyramine binding study. Major [3H]mepyramine binding sites with increased specific activities [( 3H]mepyramine binding vs. protein amount) were recovered from P2 fractions from both rat and guinea pig brains by differential centrifugation. Further subfractionation of both rat and guinea pig P2 fractions by a discontinuous sucrose density gradient centrifugation showed the highest recovery of [3H]mepyramine binding with further increased specific activities found in synaptic plasma membrane (SPM) fractions. Minor [3H]mepyramine binding sites with increased specific activities were detected in both rat and guinea pig P3 fractions. [3H]Mepyramine binding sites in SPM and P3 fractions showed identical Kd values in each species. These results indicate that histamine H1-receptors are located not only in synaptic but also in extra-synaptic membranes of both rat and guinea pig brains.
在一项[3H]美吡拉敏结合研究中，检测了大鼠和豚鼠脑亚细胞组分中组胺H1受体的定位。通过差速离心从大鼠和豚鼠脑的P2组分中回收了比活性增加的主要[3H]美吡拉敏结合位点（[3H]美吡拉敏结合与蛋白量之比）。通过不连续蔗糖密度梯度离心对大鼠和豚鼠的P2组分进行进一步亚分级分离，结果显示[3H]美吡拉敏结合的回收率最高，且在突触质膜（SPM）组分中比活性进一步增加。在大鼠和豚鼠的P3组分中检测到比活性增加的次要[3H]美吡拉敏结合位点。每个物种的SPM和P3组分中的[3H]美吡拉敏结合位点显示出相同的解离常数（Kd）值。这些结果表明，组胺H1受体不仅位于大鼠和豚鼠脑的突触膜中，也位于突触外膜中。
