Effects Of Exercise Training On Cardiac Fibrotic Pathway In Hypertension

Abstract

PURPOSE: An inappropriate accumulation of fibrillar collagen is a common pathologic feature of hypertensive heart disease. The purpose of this study was to evaluate the effects of exercise training on cardiac fibrosis pathways in hypertensive rats. METHODS:Masson's trichrome staining and Western blotting were performed on the excised left ventricular from thirty male spontaneously hypertensive rats, which were randomly divided into either a sedentary hypertensive group (SHR) or exercise hypertensive group (SHR-EX, running on an exercise treadmill for 60 min/day, 5 sessions/week, for 12 weeks), and from age match male Wistar-Kyoto rats which served as a sedentary normotensive group (WKY). RESULTS:Interstitial fibrosis was reduced in the SHR-EX group when compared with the SHR group (p < 0.05). The inflammatory-related protein levels of iNOS and COX-2 were decreased in the SHR-EX group when compared with the SHR group (p < 0.05). The fibrotic-related protein levels of TGF-β, p-ERK and SP1 were decreased in the SHR-EX group when compared with the SHR group (p < 0.05), except CTGF. The cardiac remodeling-associated molecules levels of uPA and MMP9 were decreased in the SHR-EX group when compared with the SHR group (p < 0.05), except MMP2. CONCLUSIONS: Exercise training suppressed the hypertension-induced iNOS/COX-2-mediated inflammatory and TGF-β/ERK-driven fibrotic pathways. Our results may provide a new therapeutic effect on cardiac protection in hypertension.