Protective effects of CNTF on retinal neurons in early diabetic rats

Ziyan Liang

Objective: To observe protective effects of CNTF against retinal neurons damage on diabetic rats in early diabetic stage.

Methods: 40 SD rats (weight between 250g and 280g ) were injected streptozotocin peritoneanouly at a dose of 60mg/kg body weigh. The DM model rats were randomly divided into 2 groups: CNTF－treated group(DM+CNTF)and diabetes control group(DM+BSS). Ciliary neurotrophic factor（1.0μg /2μL） were intravitieal injected in the eyes for CNTF－treated group, balanced satls solution（2μL） were intravitieal injected in the eyes for diabetes control group. Apoptosis of RGCs was measured by TUNEL assay and retinal ultrastructure was observed at 4W, 12W.

Results: The Blood glucose and weight in CNTF－treated group (DM+CNTF)and diabetes control group(DM+BSS) were not changes（P > 0.05）. The number of apoptotic RGCs in CNTF－treated group was significantly lower than in diabetes control group at 12W by TUNEL assay（P<0.05）. From the 4 week on, we observed that the neurons of two groups had degenerative changes by transmission electron microscopy. With the treatment of CNTF , the abnormalities were improved, such as the membrane disks spaces shrinked, photoreceptor nuclei were little swelled and chromatin condensation.

Conclusions: CNTF has no significant effects on the CNTF－treated group rats and diabetes control group such as blood glucose and weight. The treatment of CNTF showed a protective effects on RGCs and photoreceptors.