| AIM The polypeptides (PCF, Molicular weight: 912 ) was isolated from Chlamys farreri using enzyme engineering technique. We established the irradiation damage models of thymocytes caused by 60Co -ray to study the protective effects of PCF on thymocytes from the Qunming mice damaged by 60Co y-ray (3650uJ/cm2). MATHODS The cells were randomly divided into six groups: control group, 60Co groups (model, 0.5% PCF, 0.25% PCF, 0.125% PCF, 0.1%VitC). The concentration of GSH-Px, SOD, MDA, T-AOC and the cells' viability were determined by biochemical and MTT methods respectively. The free calcium, mitochondria memberine potential and the rate of apoptosis on thymocytes were tested using flow cytometry (FCM). The expressions of P53, Bax and Bcl-2 proteins were examined by immunocytochemical technica. Also we determined the p21, p38 mRNA expressions through the technique of in situ hybridiation. The ultrastructure of the cells was observed through electron microscope. RESULTS The results indicated that PCF could enhance the activities of GSH-Px, SOD, A-SAC, T-AOC and OD values in cells. The concentration of cellular free calcium was decreased by PCF. PCF decreased the amounts of ROS, MDA and the rate of apoptosis in cells. It also raised the expression of Bcl-2 gene and decreased the expression of P53, Bax. The mRNA expressions of p21 and p38 decreased in PCF groups. The ultrastructural damages of the cells were inhibited by PCF. The results showed that the observed indexes of the PCF groups are significantly different compared with model group (P<0.05). CONCLUSION PCF has the protective effects on damages of thymocytes caused by the irradiation of 60Co. The mechanisms might be related to inhibiting of the amount of ROS and raising the expression of Bcl-2 gene, increasing anti-oxidative enzymes in cells and inhibiting the lipid peroxide. |
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