Effects of dietary chromium supplementation on cardiac mass, metabolic enzymes, and contractile proteins
1995
Morris, G.S. | Guidry, K.A. | Hegsted, M. | Hasten, D.L.
Chromium, a popular but controversial micronutrient, can increase skeletal muscle growth when provided in supplemented quantities, presumably because of its suspected insulin like action. Whether chromium similarly affects cardiac muscle is an important issue because inappropriate cardiac growth can suggest decrements in cardiac performance. Therefore, the purpose of this study was to determine if chromium supplementation impacted contractile and metabolic properties of the heart. Male Sprague-Dawley rats received a semi-purified basal diet supplemented with 300 PPB chromium picolinate (CONTR), or supplemented with 1500 PPB chromium picolinate (SUPPLEM) After 12 weeks on the respective diets, animals were killed, and the left ventricles removed and analyzed for differences in cardiac metabolic and contractile proteins. Chromium supplementation failed to alter body weights, left ventricular mass, total protein content, and myofibrillar protein content citrate synthase, or hexokinase activity The amount of the high ATPase myosin isoform, V1 was diminished by 11% in the SUPPLEM group (p less than or equal to 0.05). These findings demonstrate that the adaptive response of the heart to dietary chromium supplementation is limited to changes in the myosin isoform. These changes may provide the heart with a more economical contractile apparatus without compromising cardiac performance.
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