Objective: We demonstrated previously that exercise training enhances endothelium-dependent and -independent rabbit kidney vascular relaxation. The present study investigated protein expression changes in the rabbit renal cortex induced by chronic dynamic exercise.
Design: Kidneys were obtained from New Zealand rabbits either pen confined (n=8) or treadmill trained (0% grade) for 5 days/wk at a speed of 18 m/min during 60 min over a 12-week period (n=8). Expression of proteins in the renal cortex was determined by colloidal Coomassie blue staining after two-dimensional polyacrylamide gel electrophoresis. Differencial protein spots were excised, trypsin digested and peptides sequenced by electrospray ionization-ion trap mass spectrometry.
Results: Two pairs of matching differentially stained spots displayed an approximate 3-fold increase in trained animals when compared to sedentary ones. These four spots presented a molecular mass of 23 kDa but different pI values. Mass spectrometric analyses revealed the pairs of matching spots as being rabbit apolipoprotein A-I.
Conclusion: Chronic dynamic exercise increases apolipoprotein A-I expression in the rabbit renal cortex. This fact could be involved in the alterations observed in the renal circulation after exercise training.