Effect And Primary Mechanism Of Polypeptide From Chlamys Farreri (PCF) On The Apoptosis Of Thymocytes Induced By γ-ray Irradiation

Objective To evaluate the effect and primary mechanism of polypeptide from Chlamys farreri (PCF) on the apoptosis of thymocytes induced by γ -ray irradiation. Methods Thymocytes of KM mice was given single 2Gy γ -ray irradiation with a dose rate of 0.6Gy / min. This study consisted of five groups: cells cultured in medium alone was control group, those irradiated by γ -ray was model group, and those pretreated with PCF at various concentration (0.5 mg/ml, 0.25 mg/ml, 0.125mg/ml) were experiment groups. Changes of morphologic ultrastructure, DNA ladder, enzyme, nucleic acid, and intracellular free calcium were observed. Results The ultrastructural damages of the cells were inhibited by PCF; DNA ladders were decreased; the level of MDA, a marker of lipid peroxidation, is down-regulated and the activity of SOD in group treated with 0.5 mg/ml PCF is maintained in normal level. The concentration of cellular free calcium was decreased and the apoptosis of the cells in these groups are inhibited. The differences are significant. Conclusions PCF has radioprotective effect on KM mice thymocytes damaged by γ-ray irradiation, which is associated with alleviation damage of cell membrane by inhibiting the lipid peroxide,increasing activity of anti-oxidative enzymes, decreasing concentration of cellular free calcium and arresting of cell cycle in G1.This provide PCF the base as radioprotector.