Effect of dietary taurine on plasma and blood cell taurine concentrations in cats

Taurine levels were measured in adult cats consuming casein-based diets supplemented with 0.2, 0.05, 0.02, 0.01 or 0% (wt/wt) taurine or with 0% taurine plus 5.0% L-cystine. Taurine concentrations in plasma, platelets, granulocytes and erythrocytes declined significantly with decreased dietary taurine. In the cats that did not receive the 5.0% cystine supplement, the relationship between dietary taurine intake and plasma and blood cell taurine level was nonlinear. The greatest increment in taurine concentrations occurred between the 0.02 and 0.05% taurine intakes. These findings suggest that the dietary taurine requirement for adult cats may be between 0.02 and 0.05%. Supplementation of the 0% taurine diet with 5.0% L-cystine raised taurine levels above those of the taurine-deficient diets in plasma and all blood cell types. The result of this study therefore suggest a close relationship between dietary taurine intake and blood cell taurine levels in cats. Five percent L-cystine stimulates taurine synthesis in these animals.