TAURINE DEPLETION IN THE INTACT ANIMAL STIMULATES IN-VITRO PHOSPHORYLATION OF AN SIMILAR-TO-44 KDA PROTEIN PRESENT IN THE MITOCHONDRIAL-FRACTION OF THE RAT-HEART

Sprague-Dawley rats were treated with 1.5% guanidinoethanesulfonic (GE S) acid in their water in order to deplete the taurine levels partiall y in cardiac tissue. After 6 weeks of GES treatment, in vitro phosphor ylation of a similar to 44 kDa protein present in the mitochondrial fr action of the rat heart was increased by 85%. The increase in the in v itro phosphorylation of the specific similar to 44 kDa protein after G ES treatment was reversed when the animals were subsequently given 1.5 % taurine in their drinking water For an additional 6 weeks. Taurine ( 1.5%) alone for a period of 6 weeks had no effect on the phosphorylati on of the similar to 44 kDa protein. These results suggest that taurin e has a regulatory role in the phosphorylation of a specific protein i n cardiac tissue. (C) 1996 Academic Press Limited