最近发现,在哺乳动物,不仅在肌间神经丛,而且在游离的胃平滑肌细胞上,也存在特异性的有高度亲和力的鸦片受体。最近美国Bitar和Makhlouf发现,将新鲜分散的豚鼠胃平滑肌细胞分别置于几种一定浓度的鸦片肽类及吗啡溶液中,可引起平滑肌细胞收缩,与乙酰胆硷、八肽胆囊收缩素和胃泌素引起的收缩现象很相似, It has recently been discovered that in mammals, there are also specific, highly-affinitive opioid receptors, not only in the myenteric plexus, but also in free gastric smooth muscle cells. Recently, the United States Bitar and Makhlouf found that the freshly dispersed guinea pig gastric smooth muscle cells were placed in several concentrations of opioids and morphine solution, can cause smooth muscle cell contraction, and acetylcholine, octapeptide cholecystokinin and gastrin Systolic contraction caused by the phenomenon is very similar,