Effect of a high fat diet on the metabolism and mechanical behaviour of the isolated rat heart

Abstract

The effects of a high fat, atherogenic diet was studied on the metabolism and mechanical behaviour of the isolated perfused rat heart. Palmitate and pyruvate metabolism were similar in control and fat-fed perfused hearts. Glucose uptake was lower in the fat-fed perfused heart, but the percentages of glucose converted to 14CO 2 and glycogen were similar for the two groups. Explanations for the differences in glucose uptake are discussed. Fat-fed perfused hearts, with glucose as substrate, had significantly lower values for spontaneous rate, stress relaxation and tension time per minute than control hearts. With palmitate as substrate, the fat-fed perfused hearts had decreased coronary flow rates and a greater rate of tension increase on contraction. Contraction characteristics were different when hearts were perfused with glucose, compared with palmitate, in both dietary groups.