Mukherjee A, Haghani Z, Brady J, Bush L, McBride W, Buja L M, Willerson J T
Am J Physiol. 1983 Dec;245(6):H957-61. doi: 10.1152/ajpheart.1983.245.6.H957.
In the present study, we tested the hypotheses that 1) different species have different myocardial adrenergic receptor numbers and 2) selected "slow-channel" calcium antagonists compete with alpha-adrenergic antagonists for binding to varying degrees in different species. The data obtained in the present study demonstrate that there is a markedly decreased number of alpha 1-adrenergic and increased number of beta-adrenergic receptors in canine compared with rabbit and rat myocardium. The differences in adrenergic receptor numbers exist without major differences in alpha 1-adrenergic receptor affinity in the species studied. There was no significant difference in left ventricular or plasma catecholamine content between the rat and dog. Selected slow-channel calcium antagonists compete for alpha 1-adrenergic receptor binding in rabbit, rat, and canine myocardium. However, only in rabbit myocardium does verapamil antagonize alpha 1-adrenergic receptor binding at moderate concentrations, whereas verapamil in canine and rat myocardium and 1) 600 in all three species antagonize alpha 1-adrenergic receptor binding only at relatively high concentrations. Nifedipine, a dihydropyridine-type slow-channel calcium antagonist, had no effect on prazosin binding to rat, rabbit, and dog myocardial membranes.
在本研究中，我们检验了以下假设：1）不同物种的心肌肾上腺素能受体数量不同；2）选定的“慢通道”钙拮抗剂在不同物种中与α-肾上腺素能拮抗剂的结合竞争程度各异。本研究获得的数据表明，与兔和大鼠心肌相比，犬心肌中的α1-肾上腺素能受体数量显著减少，β-肾上腺素能受体数量增加。在所研究的物种中，肾上腺素能受体数量存在差异，但α1-肾上腺素能受体亲和力并无重大差异。大鼠和犬的左心室或血浆儿茶酚胺含量无显著差异。选定的慢通道钙拮抗剂在兔、大鼠和犬心肌中竞争α1-肾上腺素能受体结合。然而，只有在兔心肌中，维拉帕米在中等浓度时拮抗α1-肾上腺素能受体结合，而在犬和大鼠心肌中，维拉帕米仅在相对高浓度时拮抗α1-肾上腺素能受体结合。硝苯地平，一种二氢吡啶型慢通道钙拮抗剂，对哌唑嗪与大鼠、兔和犬心肌膜的结合没有影响。
