牛脑动脉中α2肾上腺素能受体的证据。

Evidence for alpha 2 adrenergic receptors in bovine cerebral arteries.

作者信息

Taniguchi T, Fujiwara M, Tsukahara T, Handa H

出版信息

Adv Exp Med Biol. 1984;175:127-32. doi: 10.1007/978-1-4684-4805-4_10.

Abstract

Specific [3H]yohimbine binding to the homogenates of bovine cerebral arteries was saturable and of high affinity (KD = 21 nM) with a Bmax of 720 fmol/mg protein. On the other hand, there was no detectable specific [3H]prazosin binding to these tissues. Scatchard and Hill plot analyses of specific [3H]yohimbine binding indicated one class of binding sites. Specific binding of [3H]yohimbine was displaced effectively by alpha 2 adrenergic agents and less effectively by alpha 1 adrenergic agents. IC50 values for adrenergic drugs of [3H]yohimbine binding were as follows: yohimbine, 55 nM; tramazoline, 270 nM; clonidine, 580 nM; methoxamine, 15 microM; prazosin, 47 microM, phenylephrine, 49 microM; norepinephrine, 60 microM; epinephrine, 150 microM. These results suggest that alpha adrenergic receptors in bovine cerebral artery are mostly of the alpha 2 subtype.

摘要

特异性[³H]育亨宾与牛脑动脉匀浆的结合具有饱和性且亲和力高（解离常数KD = 21 nM），最大结合容量Bmax为720 fmol/mg蛋白。另一方面，未检测到特异性[³H]哌唑嗪与这些组织的结合。对特异性[³H]育亨宾结合进行的Scatchard和Hill图分析表明存在一类结合位点。[³H]育亨宾的特异性结合可被α₂肾上腺素能药物有效取代，而被α₁肾上腺素能药物取代的效果较差。[³H]育亨宾结合的肾上腺素能药物的半数抑制浓度（IC50）值如下：育亨宾，55 nM；曲马唑啉，270 nM；可乐定，580 nM；甲氧明，15 μM；哌唑嗪，47 μM；去氧肾上腺素，49 μM；去甲肾上腺素，60 μM；肾上腺素，150 μM。这些结果表明牛脑动脉中的α肾上腺素能受体大多为α₂亚型。