大鼠实验性胃溃疡自愈期间胰岛A细胞的结构和功能变化

目的　探讨胰岛Ａ细胞参与溃疡自愈调节的可能途径。　方法　应用形态计量、放射免疫测定及透射电镜方法，研究大鼠实验性胃溃疡自愈期间胰岛Ａ细胞的面数密度、超微结构及血清胰高血糖素的变化。　结果　与正常组及盐水组比较，Ａ细胞面数密度于溃疡后６ｄ、１０ｄ 明显增加（Ｐ＜ ０．０１）。溃疡后１４ｄ 开始呈减小趋势，２８ｄ 基本恢复正常。Ａ细胞超微结构变化在溃疡后第６～１４ｄ 较明显，主要表现为：（１）细胞核增大，异染色质减少，核周隙扩张；（２）部分Ａ 细胞粗面内质网增多，有的呈板层状排列，有的扩张成囊泡；（３）部分Ａ 细胞内分泌颗粒增多，大小不等，密度不一。血浆胰高血糖素水平从溃疡后１４ｄ 到２１ｄ 呈增高趋势（Ｐ＜ ０．０１），２８ｄ 时接近正常。　结论　胰岛Ａ细胞的形态和功能变化表明，它通过增加其细胞数目及增强其合成与分泌胰高血糖素的功能，积极参与了胃溃疡自愈的调节过程。

THE CHANGES OF STRUCTURE AND FUNCTION OF ISLET A CELLS DURING THE HEALING PROCESS OF GASTRIC ULCER IN RATS

Objective\ To explore the possible way by which the islet A cells take part in the regulation of the healing process of gastric ulcer in rats. Methods\ Using morphometry,electron microscopy and radioimmunoassay to study the changes the numerical density on area(N\-A) and ultrastructure of islet A cells and the level of glucagon during the healing process of gastric ulcer in rats. Results\ As compared with normal control group(NCG) and saline control group(SCG),the N\-A of A cells markedly increased( P <0\^01) during 6\|10 days in experimental gastric ulcer group(EUG),then declined on the 14th day and recovered on the 28th day;the obvious ultrastructure changes occurred in A cells during 6\|14 days after inducing gastric ulcer .The changes include that the nucleus was larger and rounder with the more euchromatin and dilated perinuclear space, the rough endoplasmic reticulum increased in the number or dilated into vacuole in some A cells; the number of secrete granules increased with different size and density.The level of plasma glucagon elevated remarkedbly( P <0\^01)during 14\|21 days,and recovered on the 28th day. Conclusion\ The above mentioned findings proved that the islet A cells were involved in the regulation of ulcer healing process by increasing their number and enhancing their functions of synthesizing and secreting glucagon.