The effects of decreased intracellular -taurine concentration on cardiac function in brook trout (Salvelinus fontinalis)

Abstract

Taurine (2-aminoethanesulfonic acid) is amino acid found in high concentrations in vertebrate muscle tissues. In teleosts it has been shown to be an important molecule involved in cardioprotection, osmoregulation and modulation of intracellular Ca2+. Previous studies have shown that taurine deficiency is associated with cardiomyopathy and disruptions in energy metabolism. In this study the effects of taurine deficiency on cardiac function in brook trout, Salvelinus fontinalis, was assessed in vivo using intraarterial pressure measurements and metabolite assays. We hypothesized that by feeding brook trout a diet containing β-alanine, a competitive inhibitor of taurine transporter (TauT), that differences in heart function would be discovered when compared to fish fed a control diet. The study incorporated two treatment groups, a group of brook trout fed pellets vacuum coated in β-alanine to decrease intracellular taurine concentrations and a group of brook trout fed a standard diet. This study found that brook trout who had been fed the taurine depleting β-alanine diet had similar blood pressure, heart rate and chase-to-exhaustion times as brook trout fed standard diets. A significant decrease (p=0.023) in pulse pressure was observed in brook trout fed the taurine depleting β-alanine diet. The findings of this study show that taurine deficient brook trout have altered cardiac function in comparison with brook trout fed standard diets. These findings are important understanding the physiological role of taurine in vertebrate hearts.