Niki A, Niki H, Miwa I, Lin B J
Diabetes. 1976 Jul;25(7):574-9. doi: 10.2337/diab.25.7.574.
The direct effects of alloxan on glucose-induced insulin secretion and biosynthesis and the interaction of alloxan and D-glucose anomers were studied in vitro by use of isolated islets from rat pancreas. Islets were pretreated by incubation for five minutes in media containing alloxan (0.2 mg./ml.) alone or alloxan with either the alpha or beta anomer of D-glucose (3 mg./ml.). After washing, batches of five islets were incubated in the medium supplemented with glucose (1.8 mg./ml.) for 60 minutes to observe insulin secretion and for 90 minutes to observe insulin biosynthesis. Prior exposure to alloxan alone produced marked inhibition of subsequent glucose-induced insulin secretion and biosynthesis. A significantly greater protection against these inhibitory effects of alloxan was observed by using the alpha anomer of D-glucose than the beta anomer. The anomeric preference of D-glucose for protecting islet cells from the inhibitory effect of alloxan on glucose-induced insulin secretion and biosynthesis was similar to that for triggering insulin secretion. Possible mechanisms of the inhibitory effect of alloxan and the protective effect of D-glucose anomers in connection with those of other sugars are discussed. It is suggested that a glucoreceptor, stereospecific to the alpha anomer of D-glucose, may exist for both insulin secretion and biosynthesis.
利用大鼠胰腺分离胰岛在体外研究了四氧嘧啶对葡萄糖诱导的胰岛素分泌和生物合成的直接作用以及四氧嘧啶与D-葡萄糖异头物的相互作用。胰岛在含有单独的四氧嘧啶（0.2毫克/毫升）或四氧嘧啶与D-葡萄糖的α或β异头物（3毫克/毫升）的培养基中孵育5分钟进行预处理。洗涤后，将每组5个胰岛在补充有葡萄糖（1.8毫克/毫升）的培养基中孵育60分钟以观察胰岛素分泌，并孵育90分钟以观察胰岛素生物合成。预先单独暴露于四氧嘧啶会显著抑制随后葡萄糖诱导的胰岛素分泌和生物合成。与β异头物相比，使用D-葡萄糖的α异头物观察到对四氧嘧啶这些抑制作用的显著更大的保护作用。D-葡萄糖在保护胰岛细胞免受四氧嘧啶对葡萄糖诱导的胰岛素分泌和生物合成的抑制作用方面的异头物偏好与触发胰岛素分泌的偏好相似。讨论了四氧嘧啶的抑制作用和D-葡萄糖异头物的保护作用与其他糖类相关的可能机制。有人提出，可能存在一种对D-葡萄糖α异头物具有立体特异性的葡萄糖受体，用于胰岛素分泌和生物合成。
