Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA.
Am J Physiol Gastrointest Liver Physiol. 2010 Apr;298(4):G530-4. doi: 10.1152/ajpgi.00129.2009. Epub 2010 Feb 4.
To compare the gastroesophageal junction of the human with the pig, M(2) and M(3) receptor densities and the potencies of M(2) and M(3) muscarinic receptor subtype selective antagonists were determined in gastric clasp and sling smooth muscle fibers. Total muscarinic and M(2) receptors are higher in pig than human clasp and sling fibers. M(3) receptors are higher in human compared with pig sling fibers but lower in human compared with pig clasp fibers. Clasp fibers have fewer M(3) receptors than sling fibers in both humans and pigs. Similar to human clasp fibers, pig clasp fibers contract significantly less than pig sling fibers. Analysis of the methoctramine Schild plot suggests that M(2) receptors are involved in mediating contraction in pig clasp and sling fibers. Darifenacin potency suggests that M(3) receptors mediate contraction in pig sling fibers and that M(2) and M(3) receptors mediate contraction in pig clasp fibers. Taken together, the data suggest that both M(2) and M(3) muscarinic receptors mediate the contraction in both pig clasp and sling fibers similar to human clasp and sling fibers.
为了比较人类和猪的胃食管连接处，我们在胃环和吊带平滑肌纤维中确定了 M(2)和 M(3)毒蕈碱受体密度以及 M(2)和 M(3)毒蕈碱受体亚型选择性拮抗剂的效力。与人类的环和吊带纤维相比，猪的总毒蕈碱和 M(2)受体更高。与猪的吊带纤维相比，人类的 M(3)受体更高，但与猪的环纤维相比，人类的 M(3)受体更低。在人和猪中，环纤维的 M(3)受体比吊带纤维少。与人类的环纤维相似，猪的环纤维收缩明显少于猪的吊带纤维。甲硫酸加兰他敏 Schild 图的分析表明，M(2)受体参与介导猪的环和吊带纤维的收缩。达非那新的效力表明，M(3)受体介导猪的吊带纤维的收缩，而 M(2)和 M(3)受体介导猪的环纤维的收缩。综上所述，这些数据表明，M(2)和 M(3)毒蕈碱受体都介导了猪的环和吊带纤维的收缩，与人类的环和吊带纤维相似。
