β-酪啡肽-7对大鼠离体小肠葡萄糖吸收的抑制效应

INHIBITION OF β-CASOMORPHIN-7 ON THE ABSORPTION OF GLUCOSE IN RAT'S SMALL INTESTINE IN VITRO

目的探讨β-酪啡肽-7(β-casomorphin7,β-CM7)对大鼠离体小肠吸收葡萄糖的影响以及辅助降血糖作用。方法利用翻转的大鼠离体小肠囊研究β-CM7对葡萄糖转运和小肠粘膜α-葡萄糖苷酶活性的影响,同时将纳络酮(Naloxone,NaL)阻断剂与β-CM7按2:1浓度混合,探讨影响葡萄糖吸收的阿片样机制。结果在离体情况下,β-CM7在7.5×10-7～7.5×10-5mol/L浓度范围内对葡萄糖的小肠吸收均有一定的抑制作用;抑制作用与其浓度呈正相关能够降低葡萄糖跨膜快速转运期的平均速率;对α-葡萄糖苷酶活性没有抑制作用。阿片特异性拮抗剂纳络酮对β-CM7的抑制作用没有明显逆转。结论β-CM7不能影响α-糖苷酶活性,可通过非阿片样途径抑制大鼠小肠葡萄糖的吸收。

Objective to explore the influence of β-CM7 on the absorption of glucose in rat＇s small intestine in vitro,and hypoglycemic activity. Method The effect of different concentrations of β-CM7 （ 7.5×10^-7,7.5×10^-6,7.5×10^-5 mol·L^-1） on the glucose absorption by utilizing rat＇s small intestinal sac reverted in vitro and α-glucosidase activity was observed,and its opioid mechanism was studied by choosing opioid special inhibitor called Naloxone,which was mixed with β-CM7 in the proportion of 2：1. Results β-CM7 played the role of reducing the absorption of glucose in rat＇s small intestine in vitro. Its inhibition was directly proportional to the concentration of β-CM7 but α-glucosidase activity was not inhibited. The inhibition of β-CM7 can not be blocked by Naloxone. Conclusionβ-CM7 can not inhibit α-glucosidase activity,but dose-dependently inhibit the absorption of glucose of the rat＇s small intestinal sac in vitro not through opioid mechanism.