Hedberg A, Kempf F, Josephson M E, Molinoff P B
J Pharmacol Exp Ther. 1985 Sep;234(3):561-8.
The properties of the binding of [125I]iodopindolol ([125I]IPIN) to beta adrenergic receptors on plasma membranes prepared from right atrial tissue removed during cardiac bypass surgery were investigated. Some of the patients from whom the tissue was removed had been treated before surgery with either a beta adrenergic receptor antagonist or a calcium entry blocker or both. The specific binding of [125I]IPIN to beta adrenergic receptors was saturable, stereoselective and rapidly reversible. Studies of the inhibition of the specific binding of [125I]IPIN by drugs selective for beta-1 or beta-2 adrenergic receptors suggested that both beta-1 and beta-2 adrenergic receptors are present in the tissue, with approximately 55% of the receptors having the properties of beta-2 adrenergic receptors. The density of receptors in patients not treated with beta adrenergic receptor antagonists or calcium entry blockers was approximately 80 fmol/mg of protein, whereas the density of beta adrenergic receptors in treated patients was increased by approximately 50%. The relative proportion of beta-1 to beta-2 adrenergic receptors in subjects treated with beta adrenergic receptor antagonists and/or calcium entry blockers was not significantly different from that in untreated subjects. Studies were also carried out with a limited number of samples of human ventricular muscle obtained from untreated subjects at the time of surgery. The density of receptors was lower than that observed in studies with atrial tissue. However, as with atrial tissue, approximately half of the receptors appeared to be beta-2 adrenergic receptors.
研究了[125I]碘吲哚洛尔（[125I]IPIN）与心脏搭桥手术中切除的右心房组织制备的质膜上β肾上腺素能受体的结合特性。部分被切除组织的患者在手术前曾接受β肾上腺素能受体拮抗剂或钙通道阻滞剂或两者的治疗。[125I]IPIN与β肾上腺素能受体的特异性结合具有饱和性、立体选择性且快速可逆。用β1或β2肾上腺素能受体选择性药物抑制[125I]IPIN特异性结合的研究表明，该组织中同时存在β1和β2肾上腺素能受体，约55%的受体具有β2肾上腺素能受体的特性。未接受β肾上腺素能受体拮抗剂或钙通道阻滞剂治疗的患者，其受体密度约为80 fmol/mg蛋白质，而接受治疗患者的β肾上腺素能受体密度增加了约50%。接受β肾上腺素能受体拮抗剂和/或钙通道阻滞剂治疗的受试者中，β1与β2肾上腺素能受体的相对比例与未治疗受试者无显著差异。还对手术时从未经治疗的受试者获取的少量人心室肌样本进行了研究。其受体密度低于心房组织研究中的观察值。然而，与心房组织一样，约一半的受体似乎是β2肾上腺素能受体。
