Effect of drug-induced taurine depletion on cardiac contractility and metabolism.

Myocardial taurine content was halved in rats maintained for 3 weeks on tap water containing either 1% guanidinoethylsulfonate (GES) or 3% beta-alanine. The decrease in taurine content did not affect myocardial contraction; however, it significantly altered myocardial metabolism. The major effect of the treatment was a significant stimulation in the rate of glycolysis and lactate production. The rise in glycolytic flux was associated with activation of phosphofructokinase, presumably caused by a decrease in tissue citrate levels. GES-treated hearts also contained slightly lower creatine phosphate content, but since this effect was not observed in the beta-alanine-treated hearts, it appeared to be independent of taurine depletion. The consequences of these metabolic changes are discussed.