RESUMO
Objective To study the relationship between the mRNA degradation in the retinal cells of rat after death and postmortem interval(PMI) in order to provide a new methods of inferring PMI.Methods The level of ?-actin,Pgk1 and Rpl 4 mRNA in the retinal cell of rat were measured at different time(0,2,4,6,8,10, 12,14,16,18,20,22,24,26,28h)after death by compound fluorescence RT-PCR.The rats executed immediately were used as controls.Results Within 28h after death,the absorbance value of total RNA and the level of ?-actin,Pgk1 and Rpl 4 mRNA in the retinal cells decreased along with the prolongation of PMI.The equations of linear regression fitting the relationship between mRNA degradation and PMI were as follows:Y?-actin=-4436.205X?-actin+127581.7(r2=0.976),Ypgk1=-1993.884Xpgk1+57651.54(r2=0.973),YRpl 4=-1189.791XRpl 4+34533.46(r2=0.955).The return model had remarkable statistical significance(P