The Expression Of PDGF-AA In The Rat Traumatic Cataract Models

When the lens is injuried, the aqueous will come into the lens , the lens capsule or the cortex was broken. Then, the epithelial are edema. On the other hand, the lens will become obsque because lens fiber was degenerated or scar keloid formed. Finally, the traumatic cataract(TA) happened. According to the documents that have been published, the incidence rate of TA is more than 53 % during the penetrating eye traumas. Now, we have known that lens protein, especially a - antigen can cause the Lens Induced Uveitis (LIU). During the early phrase of TA' happening, LIU accelerate the forming of lens opacities.Platelet — derived growth factor ( PDGF) was one of the first polypetide growth factors identified that signals through a cell surface tyrosine kinase receptor ( PDGFR - α) to stimulate various cellular functions including growth, proliferation, proliferation and differentiation. Since then, several related genes have been identified constituting a family of ligands ( primarily PDGF - A and B ) and their cognate receptor (PDGFR - αandβ). PDGF consists of two disulfide -linked polypeptide chains, A and B. It occurs as three isoforms ,PDGF - AA, PDGF-BB, and PDGF - AB。 Meanwhile, PDGFR occurs as three isoforms, PDGFR -αα,PDGF - ββ,PDGF - αβ. lens can express the PDGFR - a all of the live.It is still unknown whether PDGF - AA take part into the happening of TA. We want to defect the expression of PDGF - AA and PDGFR - αin the aqueous and anterior - posterior segment respectively in the Rat Traumatic Cataract Models . From the results we can identify whether PDGF - AA take part into theforming of TA, we also hope this article will attribute to clearing the machnism of LIU oMethods1 Forty - five healthy Wistar rats weighting 250 to 300 g were randomly divided into 9 groups, one is being control group, the other 8 were experimental groups.2 Established the mono — eye traumatic cataract models in experimental groups.3 Determined PDGF - A A in the aqueous by ELISA method. Assay the expression of PDGFR - a in the lens epithelial cells and uvea by immunohistochemistry method.Results1 The quantity of PDGF - AA in the aqueous changes simultaneously after the surgery. The level of the factor increased gradually 2 days later, reached the first peak on the 2nd day. Then declined gradually until the 5th day. The level increased again, reached the 2nd peak on the 8th day, more highly than the 1 st peak. Then declined sharply after that time. On the 14th day ,PDGF - AA disappeared in the aqueous. There were significant difference ( P < 0. 001) between the operated eyes and the opposite eyes of 8 experimental groups.2 Immunohistochemical staining revealed that PDGFR - a expressed by the lens epithelial^corneal endotheliaK iris ^ choroid and retina of the experimental eye on the 2nd day in the early phrase and continued expressing positively until the 14th day, then disappeared later. There was no the same appearing in the other eye.ConclusionsPDGF - AA may play important roles in the progression of traumatic cataract. It is associated with the progression of lens induced uveitis.