On the compartmentalization of catalase, fatty acyl-CoA oxidase and urate oxidase in mammalian livers, and the influence of clofibrate treatment on this microlocalization

Abstract

The compartmentalization of catalase, fatty acyl-CoA oxidase and urate oxidase was examined in the livers of mice, rats and guinea pigs, using the technique of digitonin extraction in order to avoid the trauma associated with centrifugation procedures. The results are interpreted as indicating that an appreciable proportion of catalase activity occurs in the cytoplasmic compartment of these cells. Following treatment of the animals with clofibrate, the specific activity in both peroxisomal and cytoplasmic compartments was increased, with a higher proportion of cytoplasmic catalase being evident in mice. The results for catalase were compared with those for fatty acyl-CoA oxidase and urate oxidase both of which were indicated as showing a closer association with the peroxisomal compartment than was the case for catalase. These data have been discussed in relation to their significance on present understanding of peroxisomal structure and function.

Investigation of peroxisomal lipid beta-oxidation enzymes in guinea pig liver peroxisomes by immunoblotting and immunocytochemistry.

“…However, a genuine cytoplasmic catalase in guinea pig liver has been shown by cytochemical studies (Roels et al, 1977) and by subcellular fractionation in our previous report (Yamamoto et al, 1988). Moreover, Hemsley et al (1988), using a digitonin extraction assay, reported that in isolated guinea pig hepatocytes 52% of catalase activity was recovered with the cytosolic fraction, in contrast to only 2% of the acyl-CoA oxidase, thus corroborating with a different technique the observations of this study. The localization of catalase in the nucleus of liver parenchymal cells is a novel finding which was first observed in isolated nuclear fractions (Yamamoto et al, 1988) and has now been confirmed by light and electron microscopy.…”

“…We found recently that in this species hepatic peroxisomes exhibit several unique morphological features (Masuda et al, 1991), and have reported that the peroxisomal marker enzyme catalase is localized by immunoelectron microscopy and subcellular fractionation not only in peroxisomes but also, in agreement with earlier cytochemical reports (Roels, 1977) in the cytoplasm, and in addition in the nucleus of hepatocytes (Ymamoto et al, 1988). Although an ac-tivity attributed to peroxisomal fatty acid 0-oxidation has been described in guinea pig tissues (Hemsley et al, 1988;Russo and Black, 1982;Small et al, 1980), the immunoreactivity of the individual enzyme proteins and their exact immunocytochemical localization have not yet been investigated. In this study we have used antibodies to rat liver peroxisomal 0-oxidation enzymes and have analyzed their crossreactivity with corresponding guinea pig proteins by immunoblotting, using highly pusled peroxisome fractions, and have also compared the immunocytochemical localization of peroxisomal 0-oxidation enzymes with that of catalase.…”

Liver peroxisomes in newborns from clofibrate‐treated rats. II. A biochemical study of the recovery period

“…The drug-induced catalase activity is mainly recovered in the soluble fraction, where the enzyme specific activity is consequently increased (fig 4). A similar distribution pattern has been described for liver catalase in adult PP-treated animals [4,22,26,31,38,44].…”

Dynamics of H2O2 availability to ARPE-19 cultures in models of oxidative stress

“…To produce a graded disruption of membrane compartments, serial dilutions of digitonin in medium were prepared in the range of 0.0001–1.0 mg/ml for addition to ARPE-19 cultures. Complete membrane disruption was achieved by the addition of 0.1% Triton X-100 [29,30,31] in culture medium containing serum. Fifteen minutes after the addition of digitonin or Triton X-100, H 2 O 2 was added as a pulse or glucose oxidase was added at a final concentration of 10 mU/ml to initiate H 2 O 2 generation.…”