链脲佐菌素诱导糖尿病大鼠胰腺外分泌部A、B细胞密度的变化

THE CHANGES OF THE DENSITIES OF A AND B CELLS IN THE PANCREATIC EXOCRINE PORTION OF STREPTOZOTOCIN-INDUCED DIABETIC RAT

本文应用A蛋白金银—过氧化物酶抗过氧化物酶(PAGS-PAP)双重染色法,观察了链脲佐菌素(streptozotocin,STZ)诱导的糖尿病大鼠胰腺外分泌部含高血糖素的单个A细胞(单A细胞)及合胰岛素的单个B细胞(单B细胞)密度的变化.在一次大剂量腹腔注射STZ后第5天和第10天,大鼠胰腺外分泌部单A细胞密度较对照组大鼠增加,而单B细胞密度在注射STZ后第5天较对照组大鼠减少,但在第15天与对照组大鼠接近.在第15天,一些单B细胞分布在靠近胰岛的腺泡中,岛周腺泡含单B细胞的胰岛百分率明显高于对照组.由于胰腺外分泌部的单A、单B细胞在分布特征上与中间细胞相似,在糖尿病时其数量变化也与中间细胞一致,因此,本研究所观察到的单A、单B细胞与前人报道的中间细胞有密切关系.上述单A、单B细胞密度的变化提示,在STZ诱导的糖尿病大鼠,胰腺中的B细胞被STZ破坏后,其外分泌部可能有某些细胞通过中间细胞向单A、单B细胞发生了转化或者单A、单B细胞即此转化过程中的中间细胞.

The changes of the densities of single glucagon-containing A cell (single A cell) and single insulin-containing B cell (single B cell) in the pancreatic exocrine portion of streptozo-tocin (STZ)-induced diabetic rat were observed by using protein A gold silver-peroxidase an-tiperoxidase (PAGS-PAP) double staining technique. Both on day 5 (5-day group) and day 15 (15-day group) after intraperitoneal injection of a single high dose of STZ, the density of single A cells increased significantly in the pancreatic exocrine portion of the rats treated with STZ; compared with that of the control rats. The density of single B cells decreased markedly of day 5 after STZ treatment but returned to the level of the control rat on day 15. In 15-day group, some of the single B (Sells were distributed in the pancreatic acini adjacent to the islets and the precentage of the islets the periacini of which conteined sngle B cells, was much higher than that in control group. In view of the distributive similarity of the single cells to the intermediate cells and the identity of density changes of the single cells with the intermediate cells in the pancreatic exocrine portion of diabetic animals, it was indicated that there might be a close relationship between the single cells observed in present study and the intermediate cells reported previously. Therefore, the above results suggested that, after B cells in the pancreas were destroyed in STZ-induced diabetic rats, some cells ofthe pancreatic exocine portion might be transformed into single A and single B cells through the intermediate cells, of the single cells might be the intermediate cells in the transforming process.