ISSN:
1573-4919
Keywords:
weanling rats
;
myosin isoforms
;
myofibril ATPase
;
dietary carbohydrate
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Medicine
Notes:
Abstract Dietary manipulations involving high carbohydrate feeding increase VI cardiac myosin isoform expression in hormonally deficient rats. The purpose of this study was to determine if extremes in dietary carbohydrate availability could alter cardiac myosin isoform patterns in normal weanling and adult rats. Three and six weeks of dietary manipulations (either high or low carbohydrate diets) failed to change calcium-activated myofibril ATPase activity, calcium regulated myofibril ATPase activity, or the myosin isoform distribution in the adult. In contrast, a four week, high carbohydrate diet reduced calcium activated myosin ATPase activity by 33%, calcium regulated myofibril ATPase activity by 10%, and Vl isoform expression by 66% in weanling rats. Although the low carbohydrate diet caused no change in the myosin ATPase properties, it decreased VI isoform expression by 17%. These results show that carbohydrate availability can alter cardiac myosin isoform expression in normal rats, but only at weanling age. The reason for this age-related contrast in response to dietary manipulations is unknown at this stage. The dietary manipulations may have acted directly on the heart by creating a state of malnutrition, or indirectly, by altering some developmental process which links maturation of the sympathetic nervous system with myosin isoform expression.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00229686
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