Activation of Protein Tyrosine Kinase Pathways After Rat Retinal Vein Occlusion.

Kim, Hyung Chan

Original Article

Journal of the Korean Ophthalmological Society 1999;40(2):470-480.
Published online February 1, 1999.

Activation of Protein Tyrosine Kinase Pathways After Rat Retinal Vein Occlusion.

Hyung Chan Kim

Department of Ophthalmology, College of Medicine, Hallym University, Kangnam Sacred Heart Hospital.

쥐망막정맥폐쇄후 Protein Tyrosine Kinase Pathway의 활성화

김형찬(Hyung Chan Kim)

Abstract

To determine whether an experimental retinal vein occlusion activates protein tyrosine kinase pathwas andincreases angiogenic growth factors in the rat retina. Retinal vein occlusion (RVO) was induced in the rat by occlusion of retinal veins with argon laser photocoagulation. Rat retinas were collected at 2 days, 1, 2, and 4 weeks after indection of RVO and each retina was divided into haves: an area within the distribution of the occluded vein [RVO(IN)] and an area outside the distribution of the occluded vein [RVO(OUT)]. RVO(IN) and RVO(OUT) were examined by western blot analysis. Overall tyrosine-phosphorylated proteins were increased after RVO, especially in RVO (IN) at 2 days and 1 week. The amounts of vascular endothelial growth factor (VEGF) andbasic fibroblast growth factor (bFGF) were markedly increased in RVO(IN) at 2 days and 1 week. Phospholipase Cgamma(PLCgamma), phosphatidylinositl-3 kinase (PI3-K), and mitogen-activated protein kinase (MAPK) were activated in RVO(IN) at these time points. In conclusion, RVO increased overall protein tyrosine phosphorylation in the rat retina in association with increase in angiogenic growth factors (VEGF and bFGF). These results suggest that the protein tyrosine phosphorylation may in part play a role in mitogenesis of vascular endothelial cells and other responses in the retina after RVO.

Key Words: Growth factor;Rat;Retina;Tyrosine;Vein occlusion