Acute exercise induces comparable mitochondrial biogenesis and vascular angiogenesis molecular regulators in the diabetic and non-diabetic rat myocardium

Abstract

Background: The diabetic heart is associated with mitochondrial and microvascular dysfunctions along with impaired downstream co-activators. These functions may improve with long-term exercise training. However, it is unknown how they respond to acute exercise in the diabetic compared to the non-diabetic heart.

Objective: Therefore, we aimed to evaluate and compare the acute molecular responses of mitochondrial biogenesis and angiogenic and anti-angiogenic factors to a single exercise session between the diabetic and non-diabetic heart.

Methods: Male Sprague-Dawley rats were assigned into one of four groups: 1- non-diabetic sedentary control (CS); 2- Diabetic exercise (DIEX); 3- Diabetic sedentary (DIS); and 4- non-diabetic exercise (CEX) groups. Left ventricles were obtained 6 – 7 weeks following diabetes induction and following a 60-min of treadmill running from CEX and DIEX.

Results: Vascular endothelial growth factor and hypoxia-inducible factor 1α mRNA was not different among all groups. Thrombospondin-1 mRNA was not different in CEX and DIEX and was greater in both groups than CS and DIS (P < 0.005). Peroxisome proliferator-activated receptor (PPAR)-γ coactivator (PGC-1α) expression was not different in CEX and DIEX (P = 0.4). PGC-1α expression was lower in CS compared to all groups (P < 0.001 for CEX and DIEX, and P = 0.01 for DIS vs. CS) (Malondialdehyde was not different in all groups.

Conclusion: All the above molecular responses to acute exercise were similar in the diabetic and non-diabetic hearts. This may suggest that the diabetic heart may similarly benefit from exercise in terms of mitochondrial biogenic and vascular angiogenic functions as the non-diabetic heart. Future studies should investigate the long-term training responses.