Effect of diet on plasma taurine in the cat.

Near adult cats were deprived of dietary taurine until the plasma levels were consistently below 10 microM. The source of dietary lipid (animal versus vegetable), source of protein (soy versus casein versus tuna) and level (17%, 34%, 70%) and the sulfur amino acid content of the diet were then independently varied to determine their respective effects on plasma taurine. Plasma taurine was not influenced by the source of dietary fat but was sensitive to the sulfur amino acid content of the diet independent of total protein when methionine plus cystine was below 1.55% of the diet. Therefore, it is suggested that below 1.55% total sulfur amino acids the taurine requirements of the cat may be a function of the sulfur amino acid content of the diet. No retinal lesions in the area centralis occurred.