All data were graphed with SigmaPlot 10.0 (Systat Software, Inc. San Jose, CA) and analyzed with SigmaStat 3.5 (Systat Software, Inc. San Jose, CA). Appropriate analyses of variance (ANOVA) were performed followed by the Student-Newman-Keuls (SNK) Post hoc test. All data are presented as mean ± SEM when applicable. p<0.05 was considered as statistically significant.