Micheletti R, Grider J R, Makhlouf G M
Department of Medicine, Medical College of Virginia, Richmond 23298.
Regul Pept. 1988 Jun;21(3-4):219-26. doi: 10.1016/0167-0115(88)90004-3.
Smooth muscle cells were isolated separately from the longitudinal and circular muscle layers of human jejunum obtained at surgery and used to determine whether amphibian bombesin-14 and 3 mammalian homologues, GRP-(1-27), GRP-(18-27) and neuromedin B, can cause contraction by acting directly on muscle cells. Circular and longitudinal muscle cells contracted identically in response to bombesin-14 (C50 2 x 10(-12) M). The contractile response was not affected by selective muscarinic, opioid, CCK or serotonin antagonists but was inhibited by the substance P (SP) derivative, [D-Arg1, D-Pro2, D-Trp7,9, Leu11]SP. All 3 mammalian bombesins were less potent than bombesin-14. GRP-(1-27) and GRP-(18-27) were equipotent (C50 4 x 10(-11) M) but 20 times less potent than bombesin-14. Neuromedin B (C50 6 x 10(-12) M) was 3 times less potent than bombesin-14. All bombesins, however, were more potent than other enteric neuropeptides (e.g., tachykinins, opioid peptides). The study demonstrates conclusively the ability of bombesins to cause direct contraction of intestinal smooth muscle cells.
从手术中获取的人空肠纵行肌层和环行肌层分别分离出平滑肌细胞，用于确定两栖类蛙皮素 -14 及其 3 种哺乳动物同源物，即胃泌素释放肽 -（1 - 27）、胃泌素释放肽 -（18 - 27）和神经降压素 B，是否能通过直接作用于肌肉细胞而引起收缩。环行肌细胞和纵行肌细胞对蛙皮素 -14 的收缩反应相同（半数收缩浓度为 2×10⁻¹² M）。收缩反应不受选择性毒蕈碱、阿片样物质、胆囊收缩素或 5 - 羟色胺拮抗剂的影响，但受 P 物质（SP）衍生物[D - Arg1，D - Pro2，D - Trp7,9，Leu11]SP 的抑制。所有 3 种哺乳动物蛙皮素的效力均低于蛙皮素 -14。胃泌素释放肽 -（1 - 27）和胃泌素释放肽 -（18 - 27）效力相当（半数收缩浓度为 4×10⁻¹¹ M），但效力比蛙皮素 -14 低 20 倍。神经降压素 B（半数收缩浓度为 6×10⁻¹² M）的效力比蛙皮素 -14 低 3 倍。然而，所有蛙皮素的效力均高于其他肠神经肽（如速激肽、阿片样肽）。该研究确凿地证明了蛙皮素能够直接引起肠道平滑肌细胞收缩。
