Hata F, Kondo E, Ishida H
Department of Pharmacology, Tokushima University School of Dentistry, Japan.
Jpn J Pharmacol. 1988 Mar;46(3):217-24. doi: 10.1254/jjp.46.217.
The effects of clonidine on the amylase secretory responses of rat parotid tissue were examined in vitro. Clonidine increased amylase secretion induced by the beta-adrenergic agonist isoproterenol and decreased that induced by the alpha 1-adrenergic agonist methoxamine or phenylephrine with propranolol. Clonidine itself had no significant effect on the secretion. Yohimbine prevented the effects of clonidine on the secretions induced by both adrenergic agonists. Clonidine did not have any significant effect on cyclic AMP accumulation in the tissues induced by the beta-adrenergic agonist. The parotid tissue after reserpine treatment exhibited supersensitivity to beta- and alpha 1-adrenergic agonists. In reserpine treated tissues, the stimulatory effect of clonidine on beta-agonist-induced secretion disappeared, but the inhibitory effect on alpha 1-agonist-induced secretion remained unchanged. Similar results were obtained after sympathectomy of the gland. These data suggest that the inhibitory effect of clonidine on alpha 1-agonist-induced secretion is related to a postsynaptic site, whereas its effect on beta-agonist-induced secretion is still unknown.
在体外研究了可乐定对大鼠腮腺组织淀粉酶分泌反应的影响。可乐定增加了β-肾上腺素能激动剂异丙肾上腺素诱导的淀粉酶分泌，并降低了α1-肾上腺素能激动剂甲氧明或去氧肾上腺素与普萘洛尔共同诱导的淀粉酶分泌。可乐定本身对分泌没有显著影响。育亨宾可阻止可乐定对两种肾上腺素能激动剂诱导的分泌的影响。可乐定对β-肾上腺素能激动剂诱导的组织中环磷酸腺苷（cAMP）积累没有任何显著影响。利血平处理后的腮腺组织对β-和α1-肾上腺素能激动剂表现出超敏反应。在利血平处理的组织中，可乐定对β-激动剂诱导的分泌的刺激作用消失，但对α1-激动剂诱导的分泌的抑制作用保持不变。在腺体交感神经切除术后也获得了类似的结果。这些数据表明，可乐定对α1-激动剂诱导的分泌的抑制作用与突触后位点有关，而其对β-激动剂诱导的分泌的作用仍不清楚。
