Skoglund G, Lundquist I, Ahrén B
Pancreas. 1986;1(5):415-20. doi: 10.1097/00006676-198609000-00005.
Stimulation of alpha-adrenoceptors is known to inhibit insulin secretion under a variety of conditions. In this study, the question of whether these alpha-adrenoceptors are of the alpha 1- or the alpha 2-subtype was investigated in the mouse. The selective alpha 2-adrenoceptor agonist clonidine (0.05-50 nmol/kg) was found to markedly inhibit the insulin secretory response to both glucose and the cholinergic agonist carbachol. This inhibition of insulin secretion was counteracted by the alpha 2-adrenoceptor antagonist yohimbine (2.6 mumol/kg), but not by the alpha 1-adrenoceptor antagonist prazosin (2.6 mumol/kg). In contrast, the alpha 1-adrenoceptor agonist phenylephrine (0.05-50 nmol/kg) did not affect the insulin secretory response to either glucose or carbachol. Moreover, both yohimbine and prazosin increased basal plasma insulin levels. It is concluded that alpha 1- and alpha 2-adrenoceptor blockade is followed by enhancement of basal plasma insulin levels in the mouse, whereas alpha 2-adrenoceptor stimulation but not alpha 1-adrenoceptor stimulation impairs the insulin secretory response to glucose and carbachol.
已知在多种情况下，刺激α-肾上腺素能受体会抑制胰岛素分泌。在本研究中，对小鼠体内这些α-肾上腺素能受体是α1亚型还是α2亚型的问题进行了研究。发现选择性α2-肾上腺素能受体激动剂可乐定（0.05 - 50 nmol/kg）可显著抑制对葡萄糖和胆碱能激动剂卡巴胆碱的胰岛素分泌反应。这种胰岛素分泌的抑制作用可被α2-肾上腺素能受体拮抗剂育亨宾（2.6 μmol/kg）抵消，但不能被α1-肾上腺素能受体拮抗剂哌唑嗪（2.6 μmol/kg）抵消。相反，α1-肾上腺素能受体激动剂去氧肾上腺素（0.05 - 50 nmol/kg）对葡萄糖或卡巴胆碱的胰岛素分泌反应没有影响。此外，育亨宾和哌唑嗪均提高了基础血浆胰岛素水平。得出的结论是，在小鼠中，α1-和α2-肾上腺素能受体阻断后基础血浆胰岛素水平升高，而α2-肾上腺素能受体刺激而非α1-肾上腺素能受体刺激会损害对葡萄糖和卡巴胆碱的胰岛素分泌反应。
