ACETATE UTILIZATION IN NORMAL, FASTING, AND PYRUVATE-TREATED RATS

Abstract

The metabolism of acetate is influenced by various factors, including the nutritional state of the animal and the administration of other metabolites.Bloch (1) observed that non-isotopic pyruvate stimulated the incorporation of labeled carbon from acetate into fatty acids of rat liver slices, and Pardee et al. (2) found that pyruvate decreased the output of Cl402 by kidney homogenates metabolizing radioactive acetate.Hutchens and others (3) presented data on the amount of labeled carbon dioxide which was expired and of Cl4 which was incorporated into body lipides during the 1st hour after C14-acetate administration to fasting rats.Data on the rate of oxidation of acetate by the normal rat were reported by Buchanan et al. ( 4) and by Gould and coworkers (5).In our present, study we have investigated the rate of oxidation of injected sodium acetate-l-Cl4 to Cl402 by fed and fasting rats and by rats receiving inert sodium pyruvate as well as labeled acetate.Both fasting and pyruvate administration decreased markedly the rate of oxidation of acetate to carbon dioxide.The amount of incorporation of the labeled carbon into the fatty acids of the tissues was also determined, and the most significant departure from the normal was observed in the fasted animals, in which Cl4 incorporation into fatty acids decreased sharply.EXPERIMENTAL Male Sprague-Dawley strain rats weighing from 130 to 160 gm. were divided into the following groups: Group I was non-fasted and received only CY4-acetate;' Group II was non-fasted and 1 minute prior to the labeled acetate injection received 200 mg. of non-isotopic sodium pyruvate; Group