大鼠胰腺β细胞分泌颗粒内钙离子超微结构定位的研究  

Ultrastructural localization of calcium ions in secretory granules of rat pancreatic β cells

作　　者：田登梅[1] 焦凯[1] 

机构地区：[1]第四军医大学唐都医院内分泌科,陕西西安710038

出　　处：《第四军医大学学报》2008年第6期526-528,共3页Journal of the Fourth Military Medical University

基　　金：陕西省科技攻关课题:[2004k16-G2(2)]

摘　　要：目的:观察大鼠胰腺β细胞内钙离子在亚细胞水平的分布情况.方法:用胶原酶原位灌注法分离大鼠胰岛,在含100mL/L胎牛血清、11.1mmol/L葡萄糖的RPMI-1640培养基中培养过夜后,离心,将胰岛细胞团分为实验组(外源性胰岛素100mU/L孵育240min)和对照组(外源性胰岛素100mIU/L孵育0min),采用改进的焦锑酸钾沉淀的细胞化学方法对胰腺β细胞分泌颗粒内钙离子进行超微结构定位.结果:超微结构显示胰腺β细胞内钙离子呈高电子密度的黑色颗粒状.对照组的胰岛素分泌颗粒内钙离子沉积明显高于实验组,并伴有钙离子外排.实验组胰腺β细胞靠近细胞膜区钙离子沉积增加.结论:离子细胞化学定位法是研究组织中钙离子分布的有效方法.胰腺β细胞的分泌功能可能与胰岛素分泌颗粒内钙离子浓度密切相关.AIM： To delineate the calcium ion distribution in rat pancreatic β cells. METHODS： Rat islets were isolated after in situ collagenase digestion through pancreatic duct perfusion. The islets were usually cultured overnight in RPMI 1640 media with 100mL/L fetal calf serum and 11.1 mmol/L glucose ,centrifuged, then islet cell mass was divided into treated group（ incubated with exogenous insulin for 240 min） and control group. The modified potassium pyroantimonate precipitation method was employed to localize calcium ions in secretory granules of rat pancreatic β cells for ultrastructural examination. RESULTS： Ultrastructural examinations demonstrated that abundant calcium ions displayed high electrondense black particles. Calcium ion depositions in insulin secretory granules of pancreatic β cells were more in control group with calcium ions excreting than in treated group. The calcium ions granule became bigger and concentrative near the plasma membrane in treated group. CONCLUSION： The ion capture cytochemistry is a potentially powerful investigative tool for the demonstration of tissular ionic environment. Moreover, the secretory function of pancreatic β cells is closely concerned with the density of calcium ions in insulin secretory granules.

关 键 词：焦锑酸钾 钙离子 超微结构 胰腺Β细胞 

分 类 号：Q336[生物学—遗传学]