Jd. Cremin et al., EFFECTS OF GLYCINE AND BOVINE SERUM-ALBUMIN ON INHIBITION OF PROPIONATE METABOLISM IN OVINE HEPATOCYTES CAUSED BY REDUCED PHENOLIC MONOMERS, Journal of animal science, 73(10), 1995, pp. 3009-3021
Hepatocytes isolated from sheep were incubated in the presence of redu
ced phenolics and glycine to determine the effects of these compounds
on hepatic propionate metabolism in vitro. 3-Phenylpropionic (PPA) or
t-cinnamic (CA) acids, but not benzoic (BA) or 3-(4-hydroxyphenyl)prop
ionic (40HPPA) acids, decreased conversion of propionate to glucose at
.05 mM in the absence of supplemental glycine. At 1.2 mM, all reduced
phenolics decreased conversion of propionate to glucose in the absence
of supplemental glycine. Addition of glycine to the incubation medium
linearly alleviated the inhibition by BA, PPA, or CA, suggesting that
physiological glycine concentrations limited alleviation of inhibitio
n of propionate metabolism. Hippuric acid production increased as glyc
ine concentration increased in the presence of PPA, CA, or 40HPPA. Bov
ine serum albumin did not alleviate inhibition of conversion of propio
nate to glucose caused by BA, PPA, or CA and slightly alleviated inhib
ition caused by 40HPPA (.4 mM). Of the reduced phenolics tested, PPA i
s the most likely to inhibit gluconeogenesis from propionate in ovine
liver in vivo.