胰岛淀粉样多肽对培养大鼠胰岛细胞分泌胰岛素的影响

EFFECT OF ISLET AMYLOID POLYPEPTIDE (IAPP) ON INSULIN SECRETION IN NEONATAL RAT PANCREATIC ISLET CELL MONOLAYER CULTURES

淀粉样多肽（ＩＡＰＰ）是一种新发现的由胰岛细胞分泌的激素，在非胰岛素依赖型糖尿病的发生发展中具有重要意义。本研究旨在观察ＩＡＰＰ对培养的新生大鼠胰岛细胞单层培养物胰岛素分泌的影响。取新生大鼠胰腺，用胰蛋白酶和胶原酶（ｖ型）反复消化分散细胞，ＲＰＭＩ１６４０培养液培养，碘乙酸去除成纤维细胞。于培养后７ｄ选生长一致、形态良好的单层细胞培养物用于ＩＡＰＰ实验。结果ＩＡＰＰ与培养７ｄ的胰岛细胞单层培养物孵育１．５ｈ，与不含ＩＡＰＰ的对照组比较，ＩＡＰＰ２μｍｏｌ／Ｌ时对胰岛素分泌无明显抑制作用（Ｐ＞０．０５），ＩＡＰＰ１０μｍｏｌ／Ｌ时对胰岛素分泌有明显抑制作用（Ｐ＜０．０１）。表明ＩＡＰＰ依赖剂量抑制大鼠胰岛细胞分泌胰岛素。

Pancreatic islet cells from neonatal rats, isolated by repeated exposure to a mixture solution of trypsin and collagenase (type V) , were cultured with RPMI-1640 medium in monolayer for 7 days. The problem of fibroblast overgrowth was circumvented with the addition of iodoac- etate,7- day- old monolayer cultures of islet cells were used to study the effect of islet amyloid polypeptide (IAPP) on insulin secretion during 1. 5 hour incubation period in RPMI-1640 medium. 2mol/L of IAPP did not affect insulin secretion(P> 0. 05), but 10mol/L IAPP significantly inhibited insulin secretion(P<0. 01 ). These experimental data demonstrated that IAPP has in- hibitory effect on insulin secretion in rat islet monolayer cultures in a dose-dependent manner.