Choline-deficient diet increases Z protein concentration in rat liver

Feeding rats a diet deficient in choline results in fatty liver within 1 d. We studied the effect of short-term (1-3 d) choline deficiency on rat liver Z protein (fatty acid-binding protein). Groups of three females Sprague-Dawley rats were fed ad libitum a purified diet lacking choline and L-methionine or were supplemented with 0.2% choline chloride and 0.82% L-methionine. Animals were killed after 1, 2 or 3 d of consuming control or experimental diets and hepatic Z protein was prepared. Z protein in livers from experimental and control rats were estimated with the fluorescent probe dansylamino undecanoic acid. The corresponding fatty acid-binding activity was also determined. One day of choline-deficient diet increased Z protein concentration threefold, reaching a plateau on the second and third day. Fatty acid-binding activity of Z protein remained unchanged.