Wnt1 gene expression in the heart left ventricle as a response to the various durations of the intensive exercise: An experimental study.

Objective. Myocardial fibrosis is a devastating condition causing millions of deaths yearly. Several factors, such as aging, cause myocardial fibrosis. The Wnt/β-catenin pathway is one of the critical intracellular signaling for the development of cardiac fibrosis. Molecular and cellular mechanism of myocardial fibrosis induced by intensive exercise is not well-understood. The current study evaluates the effects of short- and long-term intensive exercise on the Wnt1 gene expression in a heart left ventricle in an animal model. Methods. Twenty-one male Wistar rats (mean weight 250±50 g) were divided into three groups (n=7): 1) control group (C); 2) short-term regular intensive exercise group (S-RIE, high-intensity exercise for one month six days weekly for 60 min with speed of 35 m/min), and 3) long-term regular intensive exercise group (L-RIE, high-intensity exercise for six months six days daily for 60 min with speed of 35 m/min). The heart left ventricle was isolated at the end of the experiment, and the relative gene expression of the Wnt1 gene was measured by the Real-Time PCR. Results. The L-RIE group showed a significant increase in the Wnt1 expression compared to the S-RIE and the control group. Although no difference was observed in the Wnt1 mRNA level in the S-RIE group compared to the control group, Wnt1 mRNA level increased in the L-RIE group compared to the S-RIE group. Conclusion. The exercise duration was of a great importance in the Wnt1 gene expression. Regular intensive exercise may be involved in the formation of the myocardial fibrosis by increasing the expression of the Wnt1 gene.