Nitric oxide and the collagenous protein biosynthesis of irradiated chick chorioallantoic membrane.
April 12th, 2008 | by admin |Nitric oxide and the collagenous protein biosynthesis of irradiated chick chorioallantoic membrane.
Purpose: To study the effect of irradiation doses (2 Gy and 5 Gy) on the rate of collagenous protein biosynthesis (CPB) of chick embryo chorioallantoic membrane (CAM) and to investigate the possible role of the nitric oxide (NO) synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME), its inactive enantiomer D-NAME and the NO donor sodium nitroprusside (SNP) in this effect. Materials and methods: The originally established CAM angiogenesis model was used with few modifications described earlier. The CAM areas were irradiated on the 10th or the 14th day of embryo development with a single dose of 2 or 5 Gy and the CPB was determined 6 h later. L-NAME, D-NAME and SNP were added to the CAM after the irradiation. Results: The experiments didn\’t show any significant differences in almost all of the treatment courses. In the 10-day CAM preparations the irradiation not significantly (NS) inhibited the CAM CPB, whereas L-NAME abolished this effect only in the case of 2 Gy dose (NS). The addition of SNP or D-NAME in the post-irradiated 10-day CAM exerted radiosensitization that was significant only in the case of the combination of D-NAME with the 5 Gy dose. There was no significant effect on the respective treatments of the 14-day CAM. The CPB of the 14-day CAM was significantly lower with regard to the values of the 10-day CAM. Conclusion: The biochemical evaluation of the CAM (CPB method) seems to be not suitable for radiobiological studies. Nevertheless, the implication of NO in the X-ray induced antiangiogenicity cannot be excluded.
Hadjimichael C, Kardamakis D.
Medical Representatives Course, KES College, Nicosia, Cyprus.