Hyland L, Docherty J R
Eur J Pharmacol. 1985 Aug 27;114(3):361-4. doi: 10.1016/0014-2999(85)90381-4.
The responsiveness of prejunctional alpha 2-, postjunctional alpha 1- and postjunctional alpha 2-adrenoceptors was examined in human isolated saphenous veins from male patients in the age range 37-70. There was no age-related alteration in the prejunctional potency of the alpha 2-adrenoceptor agonist xylazine for inhibiting the stimulation-evoked overflow of tritium in tissues preincubated with [3H]noradrenaline. The alpha 2-adrenoceptor antagonist yohimbine (0.01-1 microM) and the alpha 1-adrenoceptor antagonist prazosin (0.1-1 microM) significantly reduced stimulation-evoked contractions in a concentration-dependent manner. There was no significant age-related correlation for the potency of prazosin but there was a significant negative correlation between the potency of yohimbine and age (r = 0.70, n = 11, P less than 0.05), i.e. the potency of yohimbine decreased with increasing age. The decreased postjunctional potency of yohimbine may reflect a loss of alpha 2-adrenoceptors with increasing age.
在年龄范围为37至70岁的男性患者的离体人隐静脉中，研究了接头前α2 -、接头后α1 -和接头后α2 -肾上腺素能受体的反应性。在用[3H]去甲肾上腺素预孵育的组织中，α2 -肾上腺素能受体激动剂赛拉嗪抑制刺激诱发的氚溢出的接头前效力没有与年龄相关的改变。α2 -肾上腺素能受体拮抗剂育亨宾（0.01 - 1微摩尔）和α1 -肾上腺素能受体拮抗剂哌唑嗪（0.1 - 1微摩尔）以浓度依赖性方式显著降低刺激诱发的收缩。哌唑嗪的效力没有显著的与年龄相关的相关性，但育亨宾的效力与年龄之间存在显著的负相关（r = 0.70，n = 11，P < 0.05），即育亨宾的效力随着年龄的增加而降低。育亨宾接头后效力的降低可能反映了随着年龄增加α2 -肾上腺素能受体的丧失。
