Journal of Lipid Research, Vol. 8, 688-691, November 1967
Copyright © 1967 by Lipid Research, Inc.
Effect of propionate on pyruvate metabolism in adipose tissue
L. Reshef , J. Niv , and B. Shapiro
Department of Biochemistry, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
Glyceride-glycerol formation in rat adipose tissue from pyruvate-2-14C is increased by fasting, while fatty acid synthesis is markedly depressed. In tissues of fasted animals glyceride-glycerol formation is maximal with concentrations of pyruvate exceeding 2.5 mm. With 0.25 mm pyruvate-2-14C, glyceride-glycerol formation is increased severalfold by the addition of 0.25 mm propionate. No further increase in synthesis is caused by propionate when pyruvate is supplied in optimal amounts. Addition of equimolar concentrations of acetate or pyruvate does not replace propionate.
The effect of propionate on glyceride-glycerol synthesis from pyruvate is also given by a series of even-chain fatty acids. However, only propionate promotes fatty acid synthesis in tissues of fasted and fed animals. Fixation of 14CO2 in glyceride-glycerol is dependent on the presence of propionate and is maximal in tissues of fasted rats and when pyruvate is also added. Succinate has no significant effect.
Actinomycin treatment blocks glyceride-glycerol synthesis in tissues of fed and fasted animals, in the presence and absence of propionate. At the same time, fatty acid synthesis in tissues of fasted rats is markedly increased.
Supplementary key words propionate pyruvate metabolism rat adipose tissue glyceride-glycerol actinomycin D succinate
Submitted on April 22, 1967
Accepted on August 8, 1967