Physiological Role of Peroxisomal β-Oxidation in Liver of Fasted Rats

Abstract

In the livers of fasted rats, the activity of peroxisomal palmitoyl-CoA oxidation (NADH production) was increased more rapidly and markedly than that of mitochondrial carnitine palmitoyltransferase, which is the rate limiting enzyme of mitochondrial β-oxidation. The peroxisomal oxidizing activity was about twice that of the control throughout the period of fasting (1-7 days). Carnitine acetyltransferase activity was increased to a similar extent in both peroxisomes and mitochondria. A possible physiological role of liver peroxisomes may thus be as an effective supply of NADH₂, acetyl residues and short and medium-length fatty acyl-CoA in the cells on the enhancement of peroxisomal β-oxidation of the animals under starvation; these substances thus produced may be transported into the mitochondria as energy sources.