Docherty J R, O'Malley K
Eur J Pharmacol. 1983 Nov 25;95(3-4):171-6. doi: 10.1016/0014-2999(83)90631-3.
Age-related changes in pre- and postsynaptic alpha-adrenoceptors were investigated in prostatic and epididymal portions of vasa deferentia from young adult (2-3 month) and 24 month old Sprague-Dawley rats, using the selective alpha 1-agonist amidephrine and the selective alpha 2-agonist xylazine. Effects of agonists were assessed against the isometric contraction to single pulse field stimulation. There was no change in the pre- or postsynaptic potency of amidephrine, but the presynaptic inhibitory potency of xylazine was significantly reduced in old rats. Therefore, in old rats there is a reduced sensitivity of presynaptic alpha 2- but no change in pre- or postsynaptic alpha 1-adrenoceptors and this may result in increased peripheral sympathetic neurotransmission.
利用选择性α1-激动剂酰胺福林和选择性α2-激动剂赛拉嗪，研究了年轻成年（2 - 3个月）和24个月大的斯普拉格-道利大鼠输精管前列腺部和附睾部突触前和突触后α-肾上腺素能受体的年龄相关变化。通过对单脉冲场刺激引起的等长收缩来评估激动剂的作用。酰胺福林的突触前或突触后效能没有变化，但赛拉嗪的突触前抑制效能在老年大鼠中显著降低。因此，在老年大鼠中，突触前α2-受体的敏感性降低，但突触前和突触后α1-肾上腺素能受体没有变化，这可能导致外周交感神经传递增加。
