Transient Receptor Potential Vanilloid 2 Regulates Myocardial Response to Exercise

• Published in: PloS one 2015-09, Vol.10 (9), p.e0136901-e0136901
• Main Authors: Naticchioni, Mindi, Karani, Rajiv, Smith, Margaret A, Onusko, Evan, Robbins, Nathan, Jiang, Min, Radzyukevich, Tatiana, Fulford, Logan, Gao, Xu, Apel, Ryan, Heiny, Judith, Rubinstein, Jack, Koch, Sheryl E
• Format: Article
• Language: English
• Subjects: Animals; Binding sites; Blotting, Western; Calcium; Calcium Channels - genetics; Calcium Channels - metabolism; Cardiac output; Cardiomyocytes; Echocardiography; Electrocardiography; Exercise; Gene Expression Regulation; Genetic aspects; Heart; Heart diseases; Homeostasis; Hypertrophy; Immunohistochemistry; Internal medicine; Laboratory animals; Male; Materials handling; Medicine; Mice; Mice, Knockout; Muscles; Musculoskeletal system; Myocardial Contraction; Myocardium - metabolism; Phosphorylation; Physical Conditioning, Animal; Physiological aspects; Physiology; Proteins; Real-Time Polymerase Chain Reaction; Regulators; Rodents; Skeletal muscle; Stress, Physiological; Transient receptor potential proteins; TRPV Cation Channels - genetics; TRPV Cation Channels - metabolism
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0136901

The myocardial response to exercise is an adaptive mechanism that permits the heart to maintain cardiac output via improved cardiac function and development of hypertrophy. There are many overlapping mechanisms via which this occurs with calcium handling being a crucial component of this process. Our laboratory has previously found that the stretch sensitive TRPV2 channels are active regulators of calcium handling and cardiac function under baseline conditions based on our observations that TRPV2-KO mice have impaired cardiac function at baseline. The focus of this study was to determine the cardiac function of TRPV2-KO mice under exercise conditions. We measured skeletal muscle at baseline in WT and TRPV2-KO mice and subjected them to various exercise protocols and measured the cardiac response using echocardiography and molecular markers. Our results demonstrate that the TRPV2-KO mouse did not tolerate forced exercise although they became increasingly exercise tolerant with voluntary exercise. This occurs as the cardiac function deteriorates further with exercise. Thus, our conclusion is that TRPV2-KO mice have impaired cardiac functional response to exercise.