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将分离的新生大鼠胰岛细胞,分别置入四氧嘧啶,PGE_2,PGE_2和四氧嘧啶以及高浓度葡萄糖和四氧嘧啶液进行孵育,用RIA 法测细胞内cAMP和cGMP的含量。结果表明,四氧嘧啶使胰岛细胞内 cAMP含量明显降低 cGMP含量升高cAMP/cGMP 比值比正常鼠低2.79倍,但 PGE_2预处理可以防止由四氧嘧啶引起的cAMP 的降低和 cGMP升高,使胰岛细胞内cAMP/cGMP 比值维持在接近正常水平。高浓度葡萄糖预处理虽不能防止由四氧嘧啶引起的cAMP 降低,但因能使cGMP 和cAMP 值均降低,故cAMP/cGMP 比值仍接近正常水平。单纯 PCE_2可使胰岛细胞内 cAMP含量轻度升高cGMP值略下降,cAMP/cGMP比值比正常值外高1.49倍。上述结果提示PGE_2可能是通过调节胰岛细胞内环核苷酸水平,实现其对胰岛B细胞的细胞保护作用的。
The isolated rat islets were incubated with alloxan, PGE_2, PGE_2, alloxan, and high glucose and alloxan solution. The intracellular cAMP and cGMP contents were measured by RIA. The results showed that alloxan significantly decreased the content of cAMP in islet cells and the cAMP / cGMP ratio was 2.79 times lower than that in normal mice, but preconditioning with PGE 2 could prevent the decrease of cAMP and the increase of cGMP caused by alloxan Islet intracellular cAMP / cGMP ratio maintained at near normal levels. Although high concentrations of glucose preconditioning can not prevent the reduction of cAMP caused by alloxan, cAMP / cGMP ratio is still close to the normal level because both cGMP and cAMP values are reduced. PCE2 alone could slightly increase the content of cAMP in islet cells, and the cGMP value slightly decreased. The cAMP / cGMP ratio was 1.49 times higher than the normal value. The above results suggest that PGE 2 may achieve its cytoprotective effect on pancreatic islet B cells by regulating the intracellular nucleotide level of islet cells.