Taurine Deficiency in the Kitten: Exchange and Turnover of [35S]Taurine in Brain, Retina, and Other Tissues

Abstract

Kittens fed a purified diet containing partially-purified casein as the source of protein become taurine-deficient and develop retinal degeneration. The present studies report the exchange and turnover of taurine in different areas of brain, retina and other tissues and fluids of control and taurine-deficient kittens. The various tissues and fluids have different rates of exchange and different half-lives of taurine; taurine deficiency causes a range of changes in these parameters. Generally, tissues and fluids from taurine-deficient kittens accumulated more [³⁵C]taurine and had a longer half-life of taurine than tissues and fluids from control kittens. Nine areas of brain were studied and, of these areas, olfactory bulb had the greatest concentration of taurine. Olfactory bulb resisted taurine depletion to a greater extent than other areas; and, in contrast to other areas of brain, in taurine-deficient kittens, it accumulated [³⁵S]taurine for most of the experiment. Retina resisted taurine depletion and, in taurine-deficient kittens but not in control kittens, it accumulated [³⁵S]taurine throughout the experiment. The amount of taurine conjugated to bile acids was unchanged by the taurine depletion, but the kinetic behavior was altered and was similar to that of retina. The results provide support for the suggestion that, in the kitten at least, taurine is most important for the functions of bile and retina and that taurine depletion affects retina before bile. Taurine may have special importance in olfactory bulb but not necessarily in other regions of brain.