Development of some Mitochondrial Oxidase Systems of Rat Liver

Vos, M.A. de; Wilmink, C.W.; Hommes, F.A.

doi:10.1159/000240135

Cited by 25 publications

(26 citation statements)

References 8 publications

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“…Other investigators have demonstrated that mitochondrial enzymes and coenzymes increase in the neonatal period [6,9,11]. The present study demonstrated that in the case of the two enzymes studied in the rabbit, the increase was a response to the process of birth.…”

Section: Discussionsupporting

confidence: 71%

Perinatal Regulation of Mitochondrial and Cytoplasmic Enzymes in Rabbit Liver

Smith

1970

Pediatr Res

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The control of postnatal development of the activities of cytoplasmic and mitochondrial malate dehydrogenases and of the purely mitochondrial enzyme, cytochrome oxidase, has been studied in rabbit liver. Each of the three enzymes increased 1.6-1.8-fold in activity during the first 2 days of life. Delivery of animals at varying stages of maturation demonstrated (table II) that the increase in all cases occurred when delivery was effected and was a result of some aspect of the process of birth itself.Maturation affects cytoplasmic malate dehydrogenase (MDH) differently than the two mitochondrial enzymes. Cytoplasmic MDH is relatively constant in activity in utero and increases approximately 80% whenever delivery is effected (table II, figure 1). In contrast, both the mitochondrial enzymes decrease 40 % in activity if animals remain in utero beyond normal term. Their increase (20-40%) following premature delivery is considerably smaller than the large (1.5-fold) increase following postmature delivery.Using the artificial feeding procedure developed for this study, newborn animals were maintained for 48 h in an hypoxic environment. Preliminary results suggested that development of enzyme activity was affected by hypoxia. Speculation

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Section: Discussionsupporting

confidence: 71%

Perinatal Regulation of Mitochondrial and Cytoplasmic Enzymes in Rabbit Liver

Smith

1970

Pediatr Res

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“…They suggested that this enzymatic process could be coupled to the functioning of the flavins. As shown by D e V os [8] the flavo-proteins are absent in the foetal liver of rats till 5 days before birth, and increase very rapidly afterwards. The process of direct oxidation of the reduced flavins by 0 2, provides H 20 2; we could assume that an increased production of PI20 2 could play the role of an inducer of the activity of GPX.…”

Section: Discussionmentioning

confidence: 87%

Glutathione Peroxidase in Rat Liver during Development. II. Changes in Glutathione Peroxidase during Post-Natal Development of Normal and Hypotrophic Rats

Demus-Oole¹,

Swierczewski²

1969

Neonatology

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“…Cytochrome oxidase activity has been used as an index of mitochondrial number in developing tissues (5,25). The increase in cytochrome oxidase activity that we observed after birth is probably an indication of the greater dependence of the newborn on oxidative metabolism as compared with fetal tissues which develop in a relatively anerobic milieu.…”

Section: Discussionmentioning

confidence: 99%

Metabolic Adaptation in Developing Lung

1980

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incorporation into lipids was concentrations were chosen because they gave optimal rates of greatest at 18 to 19 days of fetal development, at which time the oxidation. lung content of nonesterified fatty acids was highest.The flasks were fitted with rubber caps and polypropylene center wells and incubated in a shaking water bath at 37OC for Speculation one hr. Under these conditions, production of I4COz from labeled substrates was linear for at least 2 hr. At the end of the incubation, Tbe changes substrate oxidation and Utili~atioll observed in 0.3 ml of hymine hydroxide was injected through the serum cap developing lung probably reflect ch~nges in the avdabmty of into the center well to trap evolved "COz, the reaction was substrates and requirements for precursors to support functional terminated, and COz was released by the injection of 1 ml of 2m and mor~hologic differentiation of lung-Changes in cpochrome trichloroacetic acid through the cap down the side of the flask into oxidase activity in the postnatal period may reflect differential the incubation medium. After 45 min of further incubation, the lung growth.contents of the center well were transferred to counting vials containing 10 ml of Emnofluor (33), and radioactivity was measured in a liquid scintillation counter (35). Blanks were incubated The developing lung requires energy for growth and maturation along with the samples and treated in the same way. Standards as well as for the synthesis of surface active phospholipids which were prepared containing 100 pl of the incubation mix and counted maintain postnatal alveolar stability. Although there is consider-in 10 ml of Aquasol (33). The flasks or medium were not oxygenable information concerning glucose and fatty acid metabolism in ated because this did not affect the rate of substrate oxidation to adult lung, little is known about fatty acid and glucose oxidation COz. in the developing lung. Early work by Geyer et al. (8) showed that For measurement of fatty acid incorporation into lipid, slices adult rat lung slices oxidized radiolabeled triolein and octanoic (50 to 200 mg wet wt) were incubated at the same substrate acid to 14c02. Subsequent studies by Felts (7) using adult rat lung concentrations in 2 ml of medium. The reaction was terminated slices demonstrated oxidation of [1-"clpalmitate to I4Coz. This by transfer of the flask to ice. The medium then was aspirated, work was confirmed by Salisbury-Murphy et al. (18) in rabbit and and the tissue was washed with ice-cold 0.Wo saline until the wash later by Wang and Meng (24) in the rat. Shaw and Rhoades (19) was free of radioactivity (about five washes). The slices were then in the perfused rat lung reported that high concentrations of removed with forceps to a Dounce homogenizer and homogenized palmitate (1.8 mM) inhibited glucose oxidation to COz, suggesting in 1.6 ml of cold 0.9% saline. The homogenate was transferred to that under some conditions palmitate may be a preferred substrate. a stoppered centrifuge tube, 6 ml of chloroform:methan...

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Development of some Mitochondrial Oxidase Systems of Rat Liver

Cited by 25 publications

References 8 publications

Perinatal Regulation of Mitochondrial and Cytoplasmic Enzymes in Rabbit Liver

Perinatal Regulation of Mitochondrial and Cytoplasmic Enzymes in Rabbit Liver

Glutathione Peroxidase in Rat Liver during Development. II. Changes in Glutathione Peroxidase during Post-Natal Development of Normal and Hypotrophic Rats

Metabolic Adaptation in Developing Lung

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