Experimental early stage lesions after whole brain irradiation in rats:1HMRS in comparison with NSE and S-100 protein

Objective To study the value of1H magnetic resonance spectroscopy(1HMRS)changes and the expression of NSE and S-100 protein in Sprague-Dawley(SD)rat brain tissue irradiated by 6 MeV electron beam.Methods Fony adult SD rats were randomly divided into 2 groups:blank control and irradiation groups.The irradiation group was irradiated the whole brain of wat with a dose of 20 Gy using 6 MeV electron beam.Then the rats were performed with1HMRS on days 1,7,14 and 30 after radiation to analyze concentration changes of NAA,Cho and Cr,as compared with integra-area to calculate NAM/Cr and Cho/Cr.Immunohistochemical method Was used to measure the contents of S-100 and NSE in brain tissue.Results The expression of S-100 and NSE and the ratio of NAA/Cr and Cho/Cr after whole brain irradiation were time-dependent.Compared with those of control group.the indexes above were changed with the different dose levels at different times after radiation[F=19.6(NAA/Cr),15.32(Cho/Cr),35.15(NSE)and 17.45(S-100),P<0.05].Conclusions The changes of NAA/Cr,Cho/Cr,NSE and S-100 on the brain can act as the indexes of acute brain injury induced by radiation.1HMRS can be used to diagnose the iniury of the brain in early stage after whole brain irradiation. Key words: Radiation effects; Brain injuries; 1HMRS;  NSE; S-100 protein