Exogenous basic fibroblast growth factor increases collateral blood flow in female rats with femoral artery occlusion

The goal of this study was to determine if extended duration of FGF-2 infusion would further expand collateral blood flow (BF) in female rats with bilateral femoral artery occlusion; rats were infused with either FGF-2 or placebo intra-arterially for 14, 28, and 42 days. Blood flows were measured with isotope labeled microspheres. Blood pressure and heart rate were similar between the treatment groups by ANOVA. In Placebo groups; baseline collateral dependent blood flows to the calf muscle were 11 mL/min/100 g to 17 mL/min/100 g at 4 hours after femoral artery occlusion, calf muscle blood flow increased to 39 +/- 4.2, 49 +/- 4.2, and 48 +/- 3.3 mL/min/100 g following 16, 30, and 44 days femoral artery occlusion respectively. In FGF-2-treated groups, calf muscle blood flows were further increased by 36%, 57%, and 35% over the corresponding time point of Placebo groups (P < 0.001). Exogenous FGF-2 infusion for 28 days showed higher collateral dependent blood flows than the FGF-2 14 days infused group (P < 0.001). Extended duration of exogenous FGF-2 delivery up to 42 days failed to further expand the collateral blood flow. This implies a self-limiting mechanism that might govern the collateral vascular remodeling induced by FGF-2. Our results indicate that female rats can obtain similar extent collateral blood flow expansion as that found in the male rats.