ELISA analysis on SDF-1α levels in bone marrow (BM) and circulation at 18 h after CLI procedure. A) Significantly higher BM SDF-1α level in Wild-type (WT) Fisher rats with or without GCSF treatment than in DPP4-deficient rats with or without GCSF treatment, and higher in DPP4-deficient rats with GCSF compared with those without. * vs. † vs. ‡, P < 0.001. Apparently higher expression in WT animals without than in those with GCSF treatment without statistical significance. B) Significantly higher circulatory SDF-1α level in WT-CLI-GCSF group than in other groups, notably higher in WT-CLI rats than in DPP4-deficient rats with or without GCSF treatment that showed no difference among themselves. * vs. † vs. ‡, P < 0.001. C) No difference in SDF-1α level between BM and circulation in those with or without GCSF treatment after CLI induction in DPP4-deficient rats, whereas higher level noted in circulation than BM in WT-CLI rats with further increase in circulation than in BM after GCSF treatment. * vs. † vs. ‡ vs. §, P < 0.0001. For comparison among the four groups, statistical analysis by one-way ANOVA. * vs. other groups, P < 0.0001. Symbols (*, †, ‡, §) indicate significant difference (at 0.05 level) by Bonferroni's multiple-comparisons post hoc test (n = 6 per group).