Rat Liver Catalase Research Articles

On the heterogeneity of catalase in rat liver and experimental hepatomas of rats and mice

Two forms of catalase (H 2O 2:H 2O 2 oxidoreductase, EC 1.11.1.6) activity, soluble and lipid-bound, exist in the total homogenate as well as in mitochondria, microsomes and plasma membranes of mice liver, rat liver and hepatomas. The lipid-bound catalase activity is revealed by the treatment of the tissue with n- butanol . An inverse correlation between morphological, immunochemical characteristics (reflecting the extent of malignancy) of the hepatomas studied and the activity of the two forms of catalase was found. The nature of two forms of catalase activity is discussed. One infers that experimental data available do not favour the view of their being isozymes.

Light microscopic study of the peroxidatic activity of catalase in formaldehyde-fixed rat liver.

The peroxidatic activity of rat liver catalase was demonstrated by histochemical staining with 3,3'-diaminobenzidine as hydrogen donor. The activity was so weak that its location was hard to identify in formaldehyde-fixed cells, although high catalatic activity was present, as evidenced by the production of bubbles upon the addition of hydrogen peroxide to the incubation medium. Pretreatment of fixed sections for 60 min at 37°C with formamide, urea or trypsin enhanced the peroxidatic activity significantly. The reaction granules scattered throughout the cytoplasm of the parenchymal cells probably correspond to the peroxisomes.

Purification and Properties of Rat Erythrocyte Catalase; Comparison with Rat Liver Catalase*

Purification and Properties of Rat Erythrocyte Catalase; Comparison with Rat Liver Catalase*

Studies on the intracellular localization and incorporation of 59Fe into catalase in rat liver.

Studies on the intracellular localization and incorporation of 59Fe into catalase in rat liver.

Studies on Rat Liver Catalase

The amino acid composition of purified rat liver catalase was determined by ion exchange chromatography using a Beckman Spinco analyzer as follows (in grams of amino acid per 100g. of protein): alanine, 5.88; glycine, 4.36; valine, 6.76; leucine, 6.93; isoleucinc, 4.26; proline, 7.95; phenylalanine, 8.27; tyrosine, 5.67; tryptophan, 2.64; serine, 4.29; threonine, 5.00; cysteine, 0.37; half cystine, 0.59; methionine, 3.01; arginine, 8.54; histidine, 4.90; lysine, 7.45; aspartic acid, 14.89; glutamic acid, 13.27; amide NH3, 2.05.

Studies on Rat Liver Catalase: I. COMBINED IMMUNOCHEMICAL AND ENZYMATIC DETERMINATION OF CATALASE IN LIVER CELL FRACTIONS

Enzymatic activity measurements give incomplete information on the distribution of an enzyme among cell components. By combining an enzymatic measurement with an immunochemical assay, the existence of inactive forms of the enzyme, or of inhibitors or activators, can frequently be detected. Use of a precipitin procedure has the added advantage that the protein is isolated as it is assayed, and incorporation of labeled substrates can be followed. The distribution of catalase in rat liver cell fractions in terms of enzymatic activity has been reported by Von Euler and Heller (I), Ludewig and Chanutin (2)) Greenfield and Price (3), Thomson and Klipfel (4), de Duve et al. (5), and Fourcade and Rosenberg (6). The immunochemical approach has been employed with bovine liver (7-g)) mouse liver (lo), and rat liver (11). However, immunochemical studies have not as yet been applied to isolated cell fractions. In a previous application of the immunochemical method to rat liver, Higashi, Yagi, and Hirai (11) employed an antiserum against human red blood cell catalase which precipitated rat liver catalase to some extent. In the present work a purified preparation of rat liver catalase has been obtained as antigen. Large scale preparations of liver mitochondria were used as the starting material for the catalase purification, since it was desired to avoid possible heterogeneity due to the existence of multiple forms of catalase within the cell. For preparation of liver cell fractions a version of the de Duve procedure (12) was selected, which permitted complete recovery of fairly pure components and also yielded a lysosome-rich fraction. Separate preparations were also made of “rough surfaced” and “smooth surfaced” microsomes and purified nuclei. The distribution of catalase in these cell fractions was ascertained by both the enzymatic and immunochemical methods. Values obtained by the two methods were in good agreement except in microsomes, for which the immunochemical result was 2 to 3 times the enzymatic one.

Intracellular Localization of Catalase in Rat Liver.

Intracellular Localization of Catalase in Rat Liver.

Hormonal influences on liver catalase activity

Cortisone and hydrocortisone were found to produce a marked reduction in rat liver catalase activity, but there was no change in the activity of this enzyme in adrenalectomized rats maintained on sodium chloride. Contrary to expectations, ACTH did not alter liver catalase, even in doses of 6 mg./day. Testosterone promoted an increase of catalase activity in mature female rats but not in immature females. Castration of male rats did not alter the catalase activity to a degree that was statistically significant.