FGF2 and ischemia: Treatment with bFGF induced a 1.4-fold (P < 0.05), 1.6-fold (P < 0.05), 1.5-fold (P < 0.05), and 1.2-fold (P > 0.05) increase in the number of vascular at 4th, 7th, 14th, and 21st days after injury, respectively, suggesting that bFGF effectively promoted angiogenesis and improved the conditions of ischemia reperfusion injury in PUs (Fig. 2e, f).