Role of Endogenous Calcitonin Gene Related Peptide in the Stress Induced Retinal Cell Apoptosis

1. Jihong Yang¹
2. Yaqing Zhang¹
3. Zheng Guo²

¹Shanxi Eye Hospital, Taiyuan, China
²Shanxi Medical University, Taiyuan, China

Purpose To investigate the effect of endogenous calcitonin gene related peptide (CGRP) on retinal cell apoptosis evoked by stress of acute myocardial ischemia induced by coronary artery occlusion (CAO) in rats.

Methods The acute myocardial ischemia model was established by ligating the left anterior descending branch of coronary artery in rats, which were divided to two groups: (1) control group pretreated with physiological saline and (2) antagonism group pretreated with a specific antagonist of CGRP receptor, CGRP8-37 (10-7mol/L). The treatments were delivered by intravenous injection of the agents through caudal vein, respectively, at 15 minutes prior to CAO. The samples of the eyes were collected at 3 hours of CAO for TUNEL staining (n=12) and caspase-3 activity assay (n=12) respectively.

Results & Conclusions The retinal cell apoptosis and capase-3 activity were significantly greater in the CGRP8-37 treated animals than that treated with saline (p < 0.01), at 3 hours of CAO. The results suggest the endogenous CGRP may play a role of anti-apoptosis in the stress induced retinal cell injury.