Md. Andriamampandry et al., FOOD-DEPRIVATION MODIFIES FATTY-ACID PARTITIONING AND BETA-OXIDATION CAPACITY IN RAT-LIVER, The Journal of nutrition, 126(8), 1996, pp. 2020-2027
The involvement of lipids under starvation conditions in the shift fro
m the phase of protein sparing (phase II) to the phase of increased pr
otein breakdown (phase III) has been investigated. plasma and liver we
re sampled from fed and unfed rats at two distinct stages which were c
haracterized according to the changes in specific loss in daily body m
ass and nitrogen excretion. In the two groups of food-deprived rats co
rresponding to phases II and III, the liver concentration of triglycer
ides (mu mol/g) was significantly lower, that of cholesterol significa
ntly higher and that of the other lipid classes was moderately affecte
d compared with concentrations in fed rats. Hepatic phospholipids had
significantly higher concentrations (mol/100 mol) of 22:6(n-3) in food
-deprived rats than in fed rats. Triglycerides had significantly highe
r concentrations of stearic and arachidonic acids in livers of both gr
oups of food-deprived rats compared with fed rats. The total activity
of carnitine palmitoyl transferase [mmol/(min . liver)] was 48% higher
in rats studied at the end of phase II than in fed rats but was simil
ar in fed rats and in rats studied at the beginning of phase III. The
total activity of fatty acyl-CoA oxidase was 73% lower only in rats st
udied at the beginning of phase III when compared with fed Fats. Our r
esults indicate that during food deprivation the change in the rate of
protein utilization is associated with important qualitative and quan
titative alterations of hepatic lipids and oxidative capacity of fatty
acids. These modifications appear to be related to the change from a
preferential use of lipids to a preferential utilization of proteins.