Satoh M, Kojima C, Takayanagi I
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Chiba, Japan.
Eur J Pharmacol. 1992 Oct 6;221(1):35-41. doi: 10.1016/0014-2999(92)90769-z.
alpha 1-Adrenoceptor agents with alpha 1-adrenoceptor subtypes sensitive and insensitive to inactivation by chloroethylclonidine were characterized in single cells prepared from rabbit thoracic aorta. WB 4101, 5-methylurapidil and spiperone interacted with high- and low-affinity sites labeled by [3H]prazosin. Chloroethylclonidine 10 microM pretreatment eliminated the low-affinity sites of displacement curves obtained with WB 4101 and 5-methylurapidil but had no effect on the high-affinity site for these agents. The treatment also reduced the site of the displacement curve obtained with spiperone but eliminated only the high-affinity site. Methoxamine and clonidine, alpha-adrenoceptor agonists, interacted with binding sites labeled by [3H]prazosin. The displacement curve for methoxamine was not affected by chloroethylclonidine 10 microM pretreatment, while that for clonidine was partially eliminated by the same type of pretreatment. These results suggest that, in single cells prepared from rabbit thoracic aorta: (1) WB 4101, 5-methylurapidil and spiperone interact with differing affinity at sites labeled by [3H]prazosin; (2) chloroethylclonidine-sensitive and -insensitive [3H]prazosin binding sites correspond to those with low- and high-affinity sites for WB 4101 and 5-methylurapidil, and a high- and low-affinity for spiperone, respectively; and (3) chloroethylclonidine treatment was shown to have no effect on the displacement curve of methoxamine but a partial effect on that of clonidine.
对氯乙可乐定失活敏感和不敏感的α1-肾上腺素能受体亚型的α1-肾上腺素能受体激动剂，在兔胸主动脉制备的单细胞中进行了表征。WB 4101、5-甲基尿嘧啶和螺哌隆与[3H]哌唑嗪标记的高亲和力和低亲和力位点相互作用。10μM氯乙可乐定预处理消除了用WB 4101和5-甲基尿嘧啶获得的置换曲线的低亲和力位点，但对这些药物的高亲和力位点没有影响。该处理还降低了用螺哌隆获得的置换曲线的位点，但仅消除了高亲和力位点。α-肾上腺素能受体激动剂甲氧明和可乐定与[3H]哌唑嗪标记的结合位点相互作用。10μM氯乙可乐定预处理对甲氧明的置换曲线没有影响，而对可乐定的置换曲线有部分消除作用。这些结果表明，在兔胸主动脉制备的单细胞中：（1）WB 4101、5-甲基尿嘧啶和螺哌隆在[3H]哌唑嗪标记的位点以不同亲和力相互作用；（2）氯乙可乐定敏感和不敏感的[3H]哌唑嗪结合位点分别对应于WB 4101和5-甲基尿嘧啶的低亲和力和高亲和力位点，以及螺哌隆的高亲和力和低亲和力位点；（3）氯乙可乐定处理对甲氧明的置换曲线没有影响，但对可乐定的置换曲线有部分影响。
