Effect of a high carbohydrate diet on cardiac alpha-1 and beta adrenoceptors.

Short-term (2 weeks) administration of a high-fructose diet to euthyroid Sprague-Dawley rats results in a significant (18%) increase of cardiac beta-adrenoceptors without any change in their affinities or their distribution between the plasma membrane and a vesicular fraction. A much smaller increase occurs in the number of alpha 1-adrenoceptors (8% higher than in rats fed a regular diet). The high-carbohydrate diet induced a 39% increase in beta-adrenoceptor numbers/heart in hypothyroid animals and a 19% increase in the total number of alpha 1-adrenoceptors. These results strongly suggest that changes in cardiac performance after dietary manipulations may be mediated, in part, through enhancement of adrenergic pathways.