2.4 Statistical analyses
In Western-blot experiments, densitometric data were expressed as the ratio to GAPDH protein. The density ratio of CD73 to GAPDH or that of ECP1 to GAPDH obtained from all of the samples of rats in control group was averaged, and that obtained from the sample of individual rats was further divided by this average value to get the relative value. Data are presented as means ± SE, and compared with paired t -test or one-way ANOVA followed by Bonferroni correction when appropriate using the SPSS 17.0 software (SPSS, Inc., IL, USA). Shaprio-Wilk test and Kolmogorov-Smirnov test were run before parametric tests to make sure that the data follow a normal distribution. Significance was set atp < 0.05.