The Expression Of Platelet-derived Growth Factor-A And Its Receptor In Acute β-irradiated Skin Injury In Rats

Objective: To investigate the dynamic expression of platelet-derived growth factor-A (PDGF-A) and its receptor alpha (PDGFR-α) in acute radiation-induced skin ulcers, and to explore the underlying mechanism involved in retarded healing of the ulcer.Methods: Fifty-four female SD rats were divided into 3 groups.The model of acute radiation-induced skin ulcers in rats was replicated with 45 Gy electron acceleratorβ-ray to the skin(radiation group,R,n= 24); The model of second deep degree scald in rats was established by electrical scald instrument with constant temperature, 80℃, 8s and 25㎜were regarded as common traumatogenic factors respectively(B,n=24); and 6 normal rats were served as normal control group(N,n=6). The expression of PDGF-A and PDGFR-αprotein and PDGF-A mRNA and PDGFR-αmRNA was respectively assessed by means of histochemistry and in RT-PCR.Results:①Lower expression of PDGF-A and PDGFR-αwas identified in the rat skin in normal control group.②The PDGF-A value of the absorbance in the radiation group was 10.3±1.1, 12.8±1.2, 14.0±1.2, 11.1±1.3;The burn group value of PDGF-A was 18.4±1.6, 20.0±1.6, 28.3±1.0, 19.3±1.0, there was statistical significance between the two groups(P<0.05).③The PDGFR-αvalue of the R group was 9.7±1.4, 11.1±1.4, 12.1±1.3, 10.7±1.3; and the B group was 15.4±1.4, 16.8±1.4, 18.9±1.3, 17.6±1.3, there was also statistical significance between the two groups(P<0.05).④T he results of RT-PCR for PDGF-AmRNA and PDGFR-αmRNA were in line with the results of the immunohistochemistry. Conclusion:The continuing low expression of PDGF-A and PDGFR-αmay be partially involved in the mechanism of retarded healing of acute radiation-induced skin ulcers.