糖尿病大鼠视网膜组织中cAMP和cGMP含量的变化

The Experimental Study on the Changes of Metabolism in Retinal Tissue of Diabetic Tats

目的 :探索糖尿病病程中视网膜组织的代谢机能。方法 :观察糖尿病大鼠发病后 4、6、12和 16周视网膜组织中环磷酸腺苷 (cAMP)和环磷酸鸟苷 (cGMP)含量的变化 ,并对空腹血糖 (FBG)、糖化血红蛋白 (HbA1c)和糖尿病病程进行分析。结果 :在实验各时点 ,糖尿病组大鼠cAMP含量和cAMP/cGMP比值均显著低于正常组 (P <0 .0 1) ,而cGMP含量则无明显改变 (P >0 .0 5 )。cAMP/cGMP比值下降与FBG、HbA1c和糖尿病病程密切相关。结论

Objective: To study the metabolism of retinal tissue during the course of diabetes and the contribution to the occurrence and development of diabetic retinopathy. Methods: Forty Wistar rats were divided into two groups randomly: experimental group and control group. The rats in experimental group were induced to develop diabetes by streptocotocin. The content of cyclic adenosine monophosphate (cAMP) and cyclic guanine monophosphate (cGMP) in the retinal tissue of diabetic rats was measured by simultaneous radioimmunoassay after 4, 6, 12 and 16 weeks. The relation of the cAMP/cGMP with levels of fasting blood glucose (FBG), hemoglobin glycosylation (HbA1c), and the course of disease was also analyzed. Results:During the experimental period, the levels of FBG were over 16.5 mmol/L. It was significantly higher ( P <0.01) than that of the control; The content of cAMP in the retinal tissue of diabetic rats was significantly lower ( P <0.01) than that of the control; The ratio of cAMP/cGMP was markedly lower ( P <0.01) than that of the control; The content of cGMP was not significantly decreased as compared with that in the control ( P >0.05). The decreased ratio of cAMP/cGMP was connected with the changes of FBG, HbA1c, and the course of disease. Conclusion:The metabolism function in retinal tissue of diabetic rats was disturbed, which might play a role in the occurrence and development of diabetic retinopathy.