RT-qPCR detection results of Bax mRNA. Results of analysis of variance show that the Bax mRNA expression levels in the 4 groups of rats at 6, 12 and 18 h after operation are different (P<0.05). In I°, II° and III° burn groups, the Bax mRNA expression levels are increased at 6, 12 and 18 h after operation compared with those before modeling (P<0.05), and they are higher at 12 and 18 h after operation than those at 6 h after operation (P<0.05) and also higher at 18 h after operation than those at 12 h after operation (P<0.05). At the same time point, the Bax mRNA expression levels in I°, II° and III° burn groups are higher than that in the SHAM group (P<0.05), and they are higher at each time point in the II° and III° burn groups than that in I° burn group (P<0.05) and also higher at each time point in III° burn group than that in II° burn group (P<0.05).