BODY ORGAN CYTOCHROME OXIDASE ACTIVITY IN COLD- AND WARM-ACCLIMATED RATS

The cytochrome oxidase activity was estimated in homogenates of the whole body and in nine body organs of cold- and warm-acclimated rats. The total body cytochrome oxidase activity expressed in terms of oxygen consumption was similar in cold- and warm-acclimated rats. In cold-acclimated animals the total cytochrome oxidase activity did not differ from maximal steady state metabolism measured in vivo, while in warm-acclimated rats the total cytochrome oxidase activity was almost twice as great as the maximal steady state metabolism. The results indicate that warm-acclimated rats do not utilize the full capacity of the cytochrome system and that cold-acclimation makes full exploitation of the oxidase capacity possible. In cold-acclimated rats the cytochrome oxidase activity of the muscles comprised 57% of the total, the liver 22.5%, and the skin 6%, with smaller roles for other organs. The role of the liver was greater in cold-acclimated than in warm-acclimated rats.

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Dimethyl sulfoxide elicited increase in cytochrome oxidase activity in rat liver mitochondria in vivo and in vitro

Chemico-Biological Interactions ◽

10.1016/0009-2797(88)90047-6 ◽

1988 ◽

Vol 66 (1-2) ◽

pp. 147-155 ◽

Cited By ~ 5

Author(s):

Shyamal D. Desai ◽

K.G. Chetty ◽

D.S. Pradhan

Keyword(s):

Dimethyl Sulfoxide ◽

Cytochrome Oxidase ◽

Rat Liver ◽

Oxidase Activity ◽

Liver Mitochondria ◽

Rat Liver Mitochondria ◽

Cytochrome Oxidase Activity

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Decreased cytochrome oxidase activity in hepatic mitochondria after chronic ethanol consumption and the possible role of decreased cytochrome aa3 content and changes in phospholipids

Biochimica et Biophysica Acta (BBA) - General Subjects ◽

10.1016/0304-4165(84)90252-6 ◽

1984 ◽

Vol 797 (3) ◽

pp. 320-327 ◽

Cited By ~ 90

Author(s):

M ARAI ◽

E GORDON ◽

C LIEBER

Keyword(s):

Cytochrome Oxidase ◽

Oxidase Activity ◽

Ethanol Consumption ◽

Chronic Ethanol ◽

Cytochrome Aa3 ◽

Cytochrome Oxidase Activity ◽

Chronic Ethanol Consumption

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Role of copper in mitochondrial iron metabolism

Blood ◽

10.1182/blood.v48.1.77.77 ◽

1976 ◽

Vol 48 (1) ◽

pp. 77-85 ◽

Cited By ~ 66

Author(s):

DM Williams ◽

D Loukopoulos ◽

GR Lee ◽

GE Cartwright

Keyword(s):

Cytochrome Oxidase ◽

Iron Metabolism ◽

Oxidase Activity ◽

Ferrous Iron ◽

Iron Uptake ◽

Ferric Iron ◽

Intracellular Iron ◽

Cytochrome Oxidase Activity ◽

Heme Synthesis

Abstract Heme synthesis by copper-deficient cells was investigated to elucidate the nature of the defect in intracellular iron metabolism. Iron uptake from transferrin by copper-deficient reticulocytes was 52% of normal, and the rate of heme synthesis was 33% of normal. Hepatic mitochondria isolated from copper-deficient animals were deficient in cytochrome oxidase activity and failed to synthesize heme from ferric iron (Fe III) and protoporphyrin at the normal rate. The rate of heme synthesis correlated with the cytochrome oxidase activity. Heme synthesis from Fe(III) and protoporphyrin by normal mitochondria was enhanced by succinate and inhibited by malonate, antimycin A, azide, and cyanide. It is proposed that an intact electron transport system is required for the reduction of Fe(III), thereby providing a pool of ferrous iron (Fe II) for protoheme and heme a synthesis.

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Effect of light stimulation on the cytochemical localization of cytochrome C oxidase in photoreceptor cells of cichlid fish.

Journal of Histochemistry & Cytochemistry ◽

10.1177/43.9.7642964 ◽

1995 ◽

Vol 43 (9) ◽

pp. 917-925 ◽

Cited By ~ 1

Author(s):

K H Körtje ◽

D Körtje ◽

H Rahmann

Keyword(s):

Enzyme Activity ◽

Cytochrome Oxidase ◽

Oxidase Activity ◽

Cichlid Fish ◽

Photoreceptor Cells ◽

Rod Photoreceptor ◽

Short Term ◽

Cytochemical Localization ◽

Cytochrome Oxidase Activity

Cytochrome oxidase activity was evaluated cytochemically in rod photoreceptor cells in the retina of the cichlid fish Oreochromis mossambicus after different stimulation protocols. The enzyme activity was assessed semiquantitatively by estimating the volume ratio of mitochondria classified according to the intensity of enzyme reactivity. Dark adaptation for 5 hr induced an increase of cytochrome oxidase activity both in vivo and in vitro, i.e., in isolated retinas. Short-term illumination (1 hr) of isolated retinas adapted previously in vivo to darkness caused a significant decrease of enzyme activity, whereas short-term darkening after in vivo light adaptation had no effect. Chemical stimulation for 15 min with increased K+ concentration (20 mM) reduced the enzyme activity, i.e., chemical depolarization did not have the same effect as depolarization induced by darkening. Significant changes in cytochrome oxidase activity were apparent within 1 hr of stimulation, so that this method for analysis of neuronal activity can be applied even in short-term experiments.

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Role of copper in mitochondrial iron metabolism

Blood ◽

10.1182/blood.v48.1.77.bloodjournal48177 ◽

1976 ◽

Vol 48 (1) ◽

pp. 77-85 ◽

Cited By ~ 1

Author(s):

DM Williams ◽

D Loukopoulos ◽

GR Lee ◽

GE Cartwright

Keyword(s):

Cytochrome Oxidase ◽

Iron Metabolism ◽

Oxidase Activity ◽

Ferrous Iron ◽

Iron Uptake ◽

Ferric Iron ◽

Intracellular Iron ◽

Cytochrome Oxidase Activity ◽

Heme Synthesis

Heme synthesis by copper-deficient cells was investigated to elucidate the nature of the defect in intracellular iron metabolism. Iron uptake from transferrin by copper-deficient reticulocytes was 52% of normal, and the rate of heme synthesis was 33% of normal. Hepatic mitochondria isolated from copper-deficient animals were deficient in cytochrome oxidase activity and failed to synthesize heme from ferric iron (Fe III) and protoporphyrin at the normal rate. The rate of heme synthesis correlated with the cytochrome oxidase activity. Heme synthesis from Fe(III) and protoporphyrin by normal mitochondria was enhanced by succinate and inhibited by malonate, antimycin A, azide, and cyanide. It is proposed that an intact electron transport system is required for the reduction of Fe(III), thereby providing a pool of ferrous iron (Fe II) for protoheme and heme a synthesis.

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