Nishimura J, Kanaide H, Miwa N, Nakamura M
Biochem Biophys Res Commun. 1985 Jan 16;126(1):594-601. doi: 10.1016/0006-291x(85)90647-3.
We studied the subcellular distribution and the properties of [3H] mepyramine binding in the porcine vascular smooth muscle. A close correlation was observed between the specific binding activity of [3H] mepyramine and the extent of the enrichment of sarcolemmal marker enzyme in 4 subfractions obtained by sucrose density gradient centrifugation of the aortic microsome. In the binding isotherm in the sarcolemmal fractions from the aorta and coronary artery, there was no difference in the Kd value, but the Bmax of the coronary artery was significantly lower than that of the aorta. Thus, there is a single type of high affinity mepyramine binding site in the porcine vascular smooth muscle sarcolemma and the number of H1-receptors of the coronary artery may be smaller than that of the aorta.
我们研究了[3H]美吡拉敏在猪血管平滑肌中的亚细胞分布及结合特性。通过对主动脉微粒体进行蔗糖密度梯度离心得到4个亚组分，观察到[3H]美吡拉敏的特异性结合活性与肌膜标记酶的富集程度之间存在密切相关性。在主动脉和冠状动脉肌膜组分的结合等温线中，解离常数（Kd）值没有差异，但冠状动脉的最大结合量（Bmax）显著低于主动脉。因此，猪血管平滑肌肌膜中存在单一类型的高亲和力美吡拉敏结合位点，且冠状动脉的H1受体数量可能比主动脉的少。
