生长抑素对链佐霉素引起的糖耐量和胰岛素改变的影响

EFFECT OF SOMATOSTATIN ON THE ABNORMAL GLUCOSE TOLERANCE INDUCED BY STREPTOZOTOCIN

本工作以糖耐量为背景,观察链佐霉素(streptozotocin,STZ)对大鼠胰岛B细胞的破坏作用以及生长抑素(somatostatin,SS)的预防作用。腹腔注射STZ(35mg/kg)的大鼠经口灌注葡萄糖(5g/kg)以后,血糖急剧升高,并在第150min时仍然持续上升,达到355.59±45.66mg%。血清胰岛素在葡萄糖刺激后无明显升高,未出现正常的分泌高峰。在STZ注射前10min,预先注射生长抑素(30μg/kg,SC)则口服葡萄糖后的糖耐量曲线和血清胰岛素反应均与正常对照组相类似:在30min时,血糖呈现高峰,并在灌糖后150min逐渐趋于基础水平,生长抑素预防组与STZ损伤组比较差异显著。在口服糖负荷后第30min,生长抑素预防组大鼠血清胰岛素分泌显著增高,出现了正常的胰岛素分泌峰,其幅度比基础值高78.43±14.33%,与STZ损伤组相比,差异极为显著。本实验结果与我们在大鼠离体胰腺灌流实验中观察到的STZ引起胰腺对高糖刺激反应缺如可被生长抑素翻转的现象完全一致,从而进一步证明了生长抑素对大鼠胰岛B细胞的保护作用。

Glucose tolerance test was used in this study to observe the secretory function of islet B cells in rats 24 hours after administration of somatostatin(SS, 30μg / kg, sc) and streptozotocin (STZ, 35mg / kg, ip). At the 30th minute after glucose loading (5g / kg, orally), the blood glucose level was higher in the STZ-injured rats than that pretreated with SS 10 minutes prior to STZ, the blood glucose level of which was nearly the same as normal control rats. There was no insulin secretory peak in STZ group after glucose loading, this was significantly different from the SS-pretreated and the normal groups in which a sharp peak of insulin secretion was shown. The blood glucose level in STZ-treated rats was still maintained at a high level 150 minutes after giucose loading time, whereas the blood glucose levels of both SS-pretreated and normal groups returned nearly to basal level. The above results are in agreement with our results obtained in isolated perfused rat pancreas and confirm the preventive effect of SS on the injury of islet B cells.