Girard F, Bachelard H, St-Pierre S, Rioux F
Eur J Pharmacol. 1984 Jul 20;102(3-4):489-97. doi: 10.1016/0014-2999(84)90570-3.
The contractile activity of bombesin (BB) and related peptides including the gastrin releasing peptide (GRP) was evaluated in the rat stomach strip. BB and GRP were found to elicit concentration-dependent contractile effects in concentrations varying between 5.0 X 10(-10) and 5.0 X 10(-7) M. EC50 values of BB and GRP were 6.5 X 10(-9) and 10(-8) M, respectively. The contractile effect of BB (1.5 X 10(-8) M) was not modified by a mixture of antagonists containing atropine (1.7 X 10(-6) M), mepyramine (1.2 X 10(-6) M), methysergide (1.4 X 10(-6) M), phentolamine (1.8 X 10(-6) M), propranolol (1.9 X 10(-6) M) and indomethacin (7.0 X 10(-6) M), nor by the nerve paralyzing drug tetrodotoxin (1.6 X 10(-6) M). These results suggest the existence of BB receptors in the rat stomach strip. The results also suggest that the contractile effects of BB in this tissue result from a direct effect on the smooth muscle cell. The data derived from our structure-activity study indicate that deletion of the N-terminal sequence pGlu1-Gln2-Arg3-Leu4-Gly5- from the BB molecule causes practically no loss of affinity and intrinsic activity. Further shortening of BB gives rise to a gradual reduction of both parameters. Residual contractile activity could still be observed with the tetra- and pentapeptide BB-(11-14) and BB-(10-14) at 10(-5) M.(ABSTRACT TRUNCATED AT 250 WORDS)
在大鼠胃条上评估了蛙皮素（BB）及包括胃泌素释放肽（GRP）在内的相关肽的收缩活性。发现BB和GRP在5.0×10⁻¹⁰至5.0×10⁻⁷ M的浓度范围内可引发浓度依赖性收缩效应。BB和GRP的半数有效浓度（EC50）值分别为6.5×10⁻⁹ M和10⁻⁸ M。含有阿托品（1.7×10⁻⁶ M）、甲氧苄胺嘧啶（1.2×10⁻⁶ M）、甲基麦角新碱（1.4×10⁻⁶ M）、酚妥拉明（1.8×10⁻⁶ M）、普萘洛尔（1.9×10⁻⁶ M）和吲哚美辛（7.0×10⁻⁶ M）的拮抗剂混合物，以及神经麻痹药物河豚毒素（1.6×10⁻⁶ M），均未改变BB（1.5×10⁻⁸ M）的收缩效应。这些结果表明大鼠胃条中存在BB受体。结果还表明，BB在该组织中的收缩效应是对平滑肌细胞直接作用的结果。我们结构 - 活性研究的数据表明，从BB分子中缺失N端序列pGlu1 - Gln2 - Arg3 - Leu4 - Gly5 - 实际上不会导致亲和力和内在活性的丧失。BB进一步缩短会导致这两个参数逐渐降低。在10⁻⁵ M时，四肽和五肽BB - (11 - 14)和BB - (10 - 14)仍可观察到残余收缩活性。（摘要截短至250字）
