Exercise training enhances basic fibroblast growth factor-induced collateral blood flow

Area of Science:

• Physiology
• Vascular Biology
• Exercise Science

Background:

• Peripheral artery disease impairs blood flow, leading to muscle ischemia.
• Basic fibroblast growth factor (bFGF) promotes collateral vessel development.
• The role of exercise in augmenting bFGF-mediated angiogenesis is not fully understood.

Purpose of the Study:

• To investigate if daily exercise enhances collateral circulation induced by exogenous basic fibroblast growth factor (bFGF) infusion.
• To assess the combined effects of bFGF and exercise on hindlimb blood flow and muscle performance.

Main Methods:

• Male Sprague-Dawley rats underwent bilateral femoral artery occlusion.
• Animals received intra-arterial bFGF or carrier solution infusions for 2 weeks.
• Subgroups were either sedentary or trained via treadmill exercise (2x daily, 5 days/wk for 4 wk).
• Muscle citrate synthase activity, hindlimb blood flow (85Sr microspheres), and muscle function were measured.

Main Results:

• Exercise training significantly increased muscle citrate synthase activity.
• bFGF infusion increased hindlimb blood flow in sedentary rats.
• Combined bFGF treatment and exercise training resulted in the greatest increase in collateral blood flow (approx. 240% in calf muscles).
• Improved blood flow correlated with enhanced calf muscle performance.

Conclusions:

• Exogenous bFGF administration combined with moderate-intensity exercise significantly enhances collateral-dependent blood flow.
• Physical activity potentiates the angiogenic response to bFGF.
• Hemodynamic factors stimulated by exercise are crucial for collateral vessel enlargement.