Five CCK (cholecystokinin)-like peptides [CCK(27-32)amide, CCK-6, CCK-7, Boc-CCK-7 and nonsulfated CCK-7] were prepared by stepwise condensation in combination with fragment condensation by the active ester procedure. The analgesic effects of these CCK-like peptides were measured in the writhing test. The ED50 value of CCK-7 was 1500 nmol/kg (1.8 mg/kg). Boc-CCK-7 appeared to reduce writhing between doses of 1 and 8 mg/kg but did not show a dose-dependent response. Other synthesic peptides produced no response even at a dose of 8 mg/kg. Our results suggested that CCK-7 is one of the shortest CCK-fragments that can retain the analgesic effect.
通过逐步缩合结合活性
酯片段缩合,制备了五种CCK(胆囊收缩素)样肽[CCK(27-32)
酰胺、CCK-6、CCK-7、Boc-CCK-7和非
硫酸化CCK-7]程序。在扭体试验中测量了这些 CCK 样肽的镇痛效果。 CCK-7的E
D50值为1500nmol/kg(1.8mg/kg)。 Boc-CCK-7 在 1 至 8 mg/kg 剂量之间似乎可以减少扭体,但没有显示出剂量依赖性反应。其他合成肽即使在 8 毫克/千克的剂量下也没有产生任何反应。我们的结果表明CCK-7是可以保留镇痛作用的最短CCK片段之一。