SEARCH · PubMed Health

Results for “Mitochondrial function”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources

PubMed1994

Modulation of rat heart mitochondrial function and the production of reactive oxygen by vitamin E deficiency.

Vitamin E, an antioxidant present in all cellular membranes, is associated with protein complexes in the inner mitochondrial membranes and may affect oxidative changes which occur in these organelles when heart tissue is subjected to hypoxia. The effect of 60 min hypoxia, after a 30 min normoxic equilibration period, on the function and the production of reactive oxygen species (ROS) by cardiac mitochondria from rats fed vitamin E sufficient or deficient diets for 9 weeks was examined. Mitochondria from the hearts of rats fed vitamin E deficient diets had 40-fold less vitamin E and were more susceptible to lipid peroxidation, as compared to heart mitochondria from rats fed vitamin E sufficient diet. Perfusion with normoxic, but not hypoxic, media significantly decreased cardiac vitamin E in deficient, but not sufficient rats. Hypoxia decreased the production of ROS by mitochondria from vitamin E sufficient hearts, compared to normoxia. A similar level of ROS production was seen after hypoxia in mitochondria from vitamin E deficient hearts. However, vitamin E deficiency alone decreased the production of ROS by mitochondria from normoxic hearts, relative to vitamin E sufficient animals. Under all conditions where the production of ROS was decreased, 1 microM calcium increased production to the maximum levels seen in vitamin E sufficient, normoxic heart mitochondria. Mitochondrial function was depressed in mitochondria from hypoxic hearts as compared to mitochondria from normoxic hearts of vitamin E sufficient rats. A similar depression of mitochondrial function was not seen in mitochondria from hypoxic hearts of vitamin E deficient rats. Compensatory changes in response to long-term vitamin E deficiency may be responsible for the differences in response to hypoxia of mitochondria from vitamin E sufficient and deficient rats.

Animals↗

PubMed1975

Effect of coumarins on mitochondrial function.

Several derivatives of coumarin inhibited mitochondrial respiration and ATPase activity. The extent of inhibition depended on the concentration of the coumarins as well as on the substituents of the coumarin ring. Some of the coumarins stimulated ATPase activity, but all of them inhibited uncoupler-stimulated ATPase activity. Coumarins with free or substituted phenolic groups were found to exert profound effects on respiration and ATPase activity.

Adenosine Triphosphatases↗

PubMed1997

The effect on mitochondrial function of the tRNA Ser(UCN)/COI A7445G mtDNA point mutation associated with maternally-inherited sensorineural deafness.

An A to G point mutation at nucleotide position 7445 in the mitochondrial DNA genome is associated with maternally-inherited sensorineural deafness in two separate human pedigrees. To determine whether this point mutation [tRNA(SER)UCN)/COI A7445G] led to sensorineural deafness by affecting cellular energy metabolism we investigated the bioenergetic function of mitochondria in lymphoblastoid cultures established from these patients. Even though essentially all of the mitochondrial DNA in these cells contained the mutation at nucleotide position 7445, there was no effect on a number of mitochondrial bioenergetic functions (mitochondrial content, membrane potential in both intact and digitonin-permeabilised cells, cellular ATP/ADP ratios and respiratory enzyme activity) when compared with control cells. The implications of these findings for both the aetiology of the sensorineural deafness associated with the A7445G mtDNA mutation, and the role of bioenergetic defects in mitochondrial DNA diseases in general are discussed.

Adenosine Triphosphate↗

PubMed2001

Effects of myocardial ischemia and reperfusion on mitochondrial function and susceptibility to oxidative stress.

We investigated the effects of ischemia duration on the functional response of mitochondria to reperfusion and its relationship with changes in mitochondrial susceptibility to oxidative stress. Mitochondria were isolated from hearts perfused by the Langendorff technique immediately after different periods of global ischemia or reperfusion following such ischemia periods. Rates of O2 consumption and H2O2 release with complex I- and complex II-linked substrates, lipid peroxidation, overall antioxidant capacity, capacity to remove H2O2, and susceptibility to oxidative stress were determined. The effects of ischemia on some parameters were time dependent so that the changes were greater after 45 than after 20 min of ischemia, or were significantly different to the nonischemic control only after 45 min of ischemia. Thus, succinate-supported state 3 respiration exhibited a significant decrease after 20 min of ischemia and a greater decrease after 45 min, while pyruvate malate-supported respiration showed a significant decrease only after 45 min of ischemia, indicating an ischemia-induced early inhibition of complex II and a late inhibition of complex I. Furthermore, both succinate and pyruvate malate-supported H2O2 release showed significant increases only after 45 min of ischemia. Similarly, whole antioxidant capacity significantly increased and susceptibility to oxidants significantly decreased after 45 min of ischemia. Such changes were likely due to the accumulation of reducing equivalents, which are able to remove peroxides and maintain thiols in a reduced state. This condition, which protects mitochondria against oxidants, increases mitochondrial production of oxyradicals and oxidative damage during reperfusion. This could explain the smaller functional recovery of the tissue and the further decline of the mitochondrial function after reperfusion following the longer period of oxygen deprivation.

Animals↗

PubMed1992

Regulation of Mitochondrial Function and Biogenesis in Cucumber (Cucumis sativus L.) Cotyledons during Early Seedling Growth.

The aim of this work was to characterize the respiratory metabolism of the greening cotyledons of cucumber (Cucumis sativus L.) during early seedling growth and to investigate how this is integrated with changes in mitochondrial biogenesis and function. In light-grown cotyledons, lipid mobilization extended from germination to 6 days postimbibition, reaching a maximum at 3 to 4 days postimbibition. The rate of dark oxygen uptake reached a maximum at 2 days postimbibition in dark-grown and 3 days postimbibition in light-grown cotyledons. Development of photosynthetic capacity occurred from 4 to 7 days postimbibition. In dark-grown cotyledons, lipid mobilization extended beyond 7 days postimbibition, and there was no greening or acquisition of photosynthetic competence. Measurements of mitochondrial function indicated that the respiratory capacity of the tissue changed such that during lipid mobilization there was a much greater capacity for the operation of the nondecarboxylating portion of the citric acid cycle (succinate to oxaloacetate), whereas during the development of photosynthetic function the activity of the remainder of the cycle (oxaloacetate to succinate) was induced. Comparison of the maximum capacities for mitochondrial substrate oxidations in vitro with the rates of in vivo substrate oxidations, predicted from the rate of lipid breakdown, indicated that mitochondria in this tissue operate at or below state 4 rates, suggesting limitation by both availability of ADP and substrate.

Journal Article↗

PubMed2004

Linoleic acid epoxide promotes the maintenance of mitochondrial function and active Na+ transport following hypoxia.

Low concentrations of arachidonic acid monoepoxides protect against ischemia/reperfusion injury. This study examined whether low concentrations of the linoleic acid monoepoxide, cis-12,13-epoxy-9-octadecenoic acid (12,13-EOA), protect renal cells against decreases in mitochondrial and transport functions induced by hypoxia/reoxygenation. Primary cultures of rabbit renal proximal tubular cells (RPTC) were pretreated with diluent or 1, 5, or 10 microM 12,13-EOA for 1 h and exposed to 2 h hypoxia/0.5 h reoxygenation in the absence of 12,13-EOA. Basal respiration, oligomycin-sensitive oxygen consumption (QO2), and ATP content decreased 31, 35 and 65%, respectively, following hypoxia/reoxygenation. Hypoxia/reoxygenation also increased mitochondrial membrane potential (DeltaPsi(m)). Pretreatment with 12,13-EOA prevented decreases in basal and oligomycin-sensitive QO2s and increases in DeltaPsi(m). Despite the protection against decreases in mitochondrial function, 12,13-EOA pretreatment did not prevent the initial decrease in intracellular ATP content following hypoxia. However, pretreatment did accelerate the recovery of intracellular ATP levels during reoxygenation. Pretreatment with 12,13-EOA also prevented hypoxia-induced decreases in active Na+ transport. Ouabain-sensitive QO2 (a marker of active Na+ transport) decreased 38% following hypoxia/reoxygenation but was maintained in RPTC pretreated with 1, 5 or 10 microM 12,13-EOA prior to hypoxia. Pretreatment of RPTC with the hydrolyzed product of 12,13-EOA, 12,13-dihydroxyoctadecenoic acid, did not have any protective effects against mitochondrial dysfunction and decreases in active Na+ transport. Thus, this is the first report demonstrating that preconditioning of RPTC with low concentrations of 12,13-EOA, but not its hydrolyzed product, maintains mitochondrial respiration, accelerates restoration of ATP levels, and prevents decreases in active Na+ transport following hypoxia/reoxygenation.

Adenosine Triphosphate↗

PubMed2005

Cytochrome c release from rat brain mitochondria is proportional to the mitochondrial functional deficit: implications for apoptosis and neurodegenerative disease.

Apoptosis may be initiated in neurons via mitochondrial release of the respiratory protein, cytochrome c. The mechanism of cytochrome c release has been studied extensively, but little is known about its dynamics. It has been claimed that release is all-or-none, however, this is not consistent with accumulating evidence of cytosolic mechanisms for 'buffering' cytochrome c. This study has attempted to model an underlying disease pathology, rather than inducing apoptosis directly. The model adopted was diminished activity of the mitochondrial respiratory chain complex I, a recognized feature of Parkinson's disease. Titration of rat brain mitochondrial respiratory function, with the specific complex I inhibitor rotenone, caused proportional release of cytochrome c from isolated synaptic and non-synaptic mitochondria. The mechanism of release was mediated, at least in part, by the mitochondrial outer membrane component Bak and voltage-dependent anion channel rather than non-specific membrane rupture. Furthermore, preliminary data were obtained demonstrating that in primary cortical neurons, titration with rotenone induced cytochrome c release that was subthreshold for the induction of apoptosis. Implications for the therapy of neurodegenerative diseases are discussed.

Animals↗

PubMed1992

31P magnetic resonance spectroscopy suggests impaired mitochondrial function in AZT-treated HIV-infected patients.

Prompted by the report of a mitochondrial myopathy associated with chronic administration of zidovudine (AZT), an inhibitor of mitochondrial DNA synthesis, we obtained 31P magnetic resonance spectra from the calf muscles of AZT-treated patients and age-matched control subjects at rest and during an exercise protocol with a 12-second time resolution. The recovery of phosphocreatine following exercise reflects mitochondrial oxidative function and was significantly delayed in the AZT-treated patients (time constants, 43.3 +/- 12.5 seconds versus control subjects, 24.4 +/- 3.9 seconds). These findings support the hypothesis that the myopathy associated with chronic AZT results from the inhibitory effects of AZT on mitochondrial DNA synthesis and, secondarily, on the inhibition of mitochondrial oxidative metabolism.

Adult↗

PubMed2006

Functional genomics in Dictyostelium: MidA, a new conserved protein, is required for mitochondrial function and development.

Genomic sequencing has revealed a large number of evolutionary conserved genes of unknown function. In the absence of characterized functional domains, the discovery of the role of these genes must rely on experimental approaches. We have selected 30 Dictyostelium discoideum genes of unknown function that showed high similarity to uncharacterized human genes and were absent in the complete proteomes from Saccharomyces cerevisiae and S. pombe. No putative functional motifs were found in their predicted encoded proteins. Eighteen genes were successfully knocked-out and three of them showed obvious phenotypes. A detailed analysis of one of them, midA, is presented in this report. Disruption of midA in Dictyostelium leads to pleiotropic defects. Cell size, growth rate, phagocytosis and macropinocytosis were affected in the mutant. During development, midA- cells showed an enhanced tendency to remain at the slug stage, and spore viability was compromised. The expression of MidA fused to GFP in midA- strain rescued the phenotype and the fused protein was located in the mitochondria. Although cellular oxygen consumption, mitochondrial content and mitochondrial membrane potential were similar to wild type, the amount of ATP was significantly reduced in the mutant suggesting a mitochondrial dysfunction. Metabolomic analysis by natural-abundance 13C-nuclear magnetic resonance has shown the lack of glycogen accumulation during growth. During starvation, mutant cells accumulated higher levels of ammonia, which inhibited normal development. We hypothesize that the lack of MidA reduces mitochondrial ATP synthetic capacity and this has an impact in some but not all energy-dependent cellular processes. This work exemplifies the potential of Dictyostelium as a model system for functional genomic studies.

Amino Acid Sequence↗

PubMed1984

Improved mitochondrial function following ischemia and reflow by ATP-MgCl2.

To determine whether infused ATP-MgCl2 affects mitochondrial adenine nucleotide translocase (ANT) activity, free fatty acids (FFAs), and Ca2+ levels, total hepatic ischemia in rats was produced for 90 min after which blood flow was allowed to return to the liver. Immediately on reflow, the animals received intravenously 0.5 ml of either saline, ATP-MgCl2 (12.5 mumol), or dopamine (6 mg/kg). Three hours after ischemia and reflow, hepatic mitochondrial FFAs and Ca2+ levels increased; however, ATP-MgCl2 infusion significantly lowered FFAs and restored Ca2+ levels. The depressed mitochondrial ANT activity was somewhat improved but not restored by circulatory support with dopamine; however, ATP-MgCl2 infusion following ischemia restored that activity. Thus the present results suggest that the improved organ function that occurs with ATP-MgCl2 infusion following ischemia may be mediated through an improvement in ischemia-induced mitochondrial function.

Adenosine Triphosphate↗

PubMed1977

Embryonic development and mitochondrial function. 2. Thiamphenicol induced embryotoxicity.

Inhibition of mitochondrial protein synthesis in rat embryos during late organogenesis leads to impaired embryonic development. 1. Thiamphenicol (TAP), similar to chloramphenicol, inhibits in vivo the synthesis of cytochrome oxidase (cytox), which is partially synthesized by the mitochondrion. Subsequently, DNA synthesis and embryonic growth are affected. 2. Embryos on day 10 and 11, in contrast to embryos on day 9 of gestation, show a high sensitivity of mitochondrial protein synthesis, measured as cytox activity. From day 10 onwards, such an inhibition leads to pronounced impairment of DNA synthesis. The rat hemochorial placenta starts functioning on day 12 of gestation. Larger doses of TAP are required to inhibit cytox and DNA synthesis for treatment after placentation rather than before placentation. 3. Dose-response relationships differ depending on the date and duration of treatment. Application of TAP for 1 day requires 10-30 mg/kg TAP to inhibit cytox synthesis and 60-100 mg/kg to impair embryonic growth. Prolongation of treatment to 4 days (day 10-13) lowers the dose required for inhibition of DNA synthesis to 10 mg TAP/kg/day. This is lower than the human therapeutic dose. Larger doses lead to embryolethality. 4. The extent of inhibition of DNA synthesis provoked by inhibition of mitochondrial protein synthesis depends on a number of factors which include: different growth rates during organogenesis, the number of mitochondria present prior to treatment, availability of extramitochondrial ATP sources and placental permeability barrier.

Animals↗

PubMed1994

Mitochondrial function and neurotoxicity.

There have been important advances in our understanding of the nuclear factors that regulate mitochondrial DNA function. Nuclear involvement in respiratory chain dysfunction is also being investigated, and evidence is accumulating that this may be more important than previously thought. In particular, the cytochrome oxidase deficiency found in senescent tissue may be caused by a nuclear rather than a mitochondrial defect. Studies continue to demonstrate a mitochondrial defect in certain neurodegenerative diseases, although controversy still surrounds the tissue distribution of such deficiencies. The relationship of such deficiencies to pathogenesis remains uncertain.

Aged↗

PubMed2002

Skeletal muscle mitochondrial function is preserved in young patients with chronic renal failure.

Patients with chronic renal failure (CRF) show limited exercise tolerance, classically attributed to anemia. However, persistence of abnormally low peak oxygen consumption, even after restoration of hemoglobin concentration with recombinant erythropoietin therapy and studies of muscle bioenergetics, suggests that the problem is located beyond hemoglobin oxygen transport. The present study is designed to assess mitochondrial respiratory chain (MRC) function from skeletal muscle of patients with CRF to determine whether there is impairment in mitochondrial oxidative capacity. We studied six young patients with CRF on regular hemodialysis and erythropoietin therapy and six healthy controls matched by age, sex, anthropometric characteristics, and physical activity. Muscle biopsy of the quadriceps was performed, and mitochondria were isolated. Mitochondrial content was estimated by means of mitochondrial yield and citrate synthase activity. Maximal capacity for oxygen consumption was measured polarographically using complex I, II, III, and IV substrates of the MRC. Individual enzyme activities of MRC complexes I to V were determined spectrophotometrically. Membrane lipid peroxidation was estimated by cis-parinaric fluorescence. Compared with controls, patients with CRF showed preserved mitochondrial content, conserved respiratory activity, intact enzyme activity of MRC complexes, and no increase in lipid peroxidation. We therefore conclude that mitochondrial function is preserved in young patients with CRF.

Adult↗

PubMed1997

Impaired mitochondrial function in microvesicular steatosis. Effects of drugs, ethanol, hormones and cytokines.

Microvesicular steatosis occurs in conditions characterized by severe impairment of the mitochondrial beta-oxidation process, due to genetic and/or acquired causes. Drugs and some endogenous compounds can sequester coenzyme A (aspirin, valproic acid), inhibit mitochondrial beta-oxidation enzymes (tetracyclines, several 2-arylpropionate anti-inflammatory drugs, amineptine and tianeptine), or inhibit both mitochondrial beta-oxidation and oxidative phosphorylation (endogenous bile acids, amiodarone, perhexiline and diethylaminoethoxyhexestrol), while female sex hormones have complex, but moderate, effects on mitochondrial structure and function. Other substances impair mitochondrial DNA transcription (interferon-alpha) or mitochondrial DNA replication (dideoxynucleosides), while alcohol abuse might accelerate the normal oxidative aging of mitochondrial DNA. When beta-oxidation is severely impaired, fatty acids, which are poorly oxidized by mitochondria, are mainly esterified into triglycerides, but there is a residual increase in non-esterified fatty acids. Triglycerides (possibly emulsified by a rim of non-esterified fatty acids) accumulate as small vesicles. Impairment of energy production, and the mitochondrial and general toxicity of both non-esterified fatty acids and dicarboxylic acids, may contribute to liver failure, coma and death in severe forms. Although milder forms of microvesicular steatosis have a good short-term prognosis, they can lead to chronic lipid peroxidation and the development of steatohepatitis lesions. Investigational molecules with a carboxylic group or a protonatable amine, or those which might interfere with mitochondrial DNA, should be screened for possible mitochondrial effects.

Animals↗

PubMed2004

Herp stabilizes neuronal Ca2+ homeostasis and mitochondrial function during endoplasmic reticulum stress.

In response to endoplasmic reticulum (ER) stress, cells launch homeostatic and protective responses, but can also activate cell death cascades. A 54 kDa integral ER membrane protein called Herp was identified as a stress-responsive protein in non-neuronal cells. We report that Herp is present in neurons in the developing and adult brain, and that it is regulated in neurons by ER stress; sublethal levels of ER stress increase Herp levels, whereas higher doses decrease Herp levels and induce apoptosis. The decrease in Herp protein levels following a lethal ER stress occurs prior to mitochondrial dysfunction and cell death, and is mediated by caspases which generate a 30-kDa proteolytic Herp fragment. Mutagenesis of the caspase cleavage site in Herp enhances its neuroprotective function during ER stress. While suppression of Herp induction by RNA interference sensitizes neural cells to apoptosis induced by ER stress, overexpression of Herp promotes survival by a mechanism involving stabilization of ER Ca(2+) levels, preservation of mitochondrial function and suppression of caspase 3 activation. ER stress-induced activation of JNK/c-Jun and caspase 12 are reduced by Herp, whereas induction of major ER chaperones is unaffected. Herp prevents ER Ca(2+) overload under conditions of ER stress and agonist-induced ER Ca(2+) release is attenuated by Herp suggesting a role for Herp in regulating neuronal Ca(2+) signaling. By stabilizing ER Ca(2+) homeostasis and mitochondrial functions, Herp serves a neuroprotective function under conditions of ER stress.

Amyloid beta-Peptides↗

PubMed2005

Ca2+-activated myosin-ATPases, creatine and adenylate kinases regulate mitochondrial function according to myofibre type in rabbit.

Mitochondrial respiration rates and their regulation by ADP, AMP and creatine, were studied at different free Ca(2+) concentrations (0.1 versus 0.4 microm) on permeabilized fibre bundles of rabbit skeletal muscles differing in their myosin heavy chain profiles. Four fibre bundle types were obtained: pure types I and IIx, and mixed types IIax (approximately 50% IIa and 50% IIx fibres) and IIb+ (60% IIb fibres, plus IIx and IIa). At rest, pure type I fibres displayed a much higher apparent K(m) for ADP (212 microm) than IIx fibres (8 microm). Within the IIax and IIb+ mixed fibre bundle types, two K(ADP)(m) values were observed (70 microm and 5 microm). Comparison between pure IIx and mixed types indicates that the intermediate K(m) of 70 microm most probably corresponds to the mitochondrial affinity for ADP in IIa fibres, the lowest K(m) for ADP (5 microm) corresponding to IIx and IIb types. Activation of mitochondrial creatine and adenylate kinase reactions stimulated mitochondrial respiration only in type I and IIax fibre bundles, indicating an efficient coupling between both kinases and ADP rephosphorylation in type I and, likely, IIa fibres, since no effect was observed in pure IIx fibres. Following Ca(2+)-induced activation of myosin-ATPase, an increase in mitochondrial sensitivity to ADP of 45% and 250% was observed in type IIax and I bundles, respectively, an effect mostly prevented by addition of vanadate, an inhibitor of myosin-ATPase. Ca(2+)-induced activation of myosin-ATPase also prevented the stimulation of respiration rates by creatine and AMP in I and IIax bundles. In addition to differential regulation of mitochondrial respiration and energy transfer systems at rest in I and IIa versus IIx and IIb muscle fibres, our results indicate a regulation of phosphotransfer systems by Ca(2+) via the stimulation of myosin-ATPases in type I and IIa fibres of rabbit muscles.

Adenylate Kinase↗

PubMed1984

Energetic efficiency and mitochondrial function in rats fed trans fatty acids.

Nutritional experiments with growing rats were conducted to study the effect of dietary t18:1 and t,t18:2 in mixtures with safflower oil (77.1% linoleate) on oxidative phosphorylation of isolated liver mitochondria and on energetic efficiency as measured in energy balance experiments. Partially hydrogenated soybean oil (PHSO) with 45% t18:1 and an ethyl ester concentrate of trans fatty acids (TRANS) containing 52% t,t18:2 were used. Six groups of male rats were fed diets with 10% (wt/wt) fat supplements: 1, safflower oil (SAF); 2, 8% PHSO + 2% SAF; 3, 0.5% TRANS + 9.5% SAF; 4, 1% TRANS + 9% SAF; 5, 2% TRANS + 8% SAF; and 6, 5% TRANS + 5% SAF. These fat supplements contained 77.1, 17.1, 73.3, 69.4, 61.7 and 38% linoleate for groups 1-6, respectively. The basal metabolic rate was not affected by dietary treatments, neither were the metabolizable energy values. As compared to the SAF group, rats receiving the 8% PHSO + 2% SAF showed no different effect on energy utilization or mitochondrial respiratory function. TRANS was found to reduce the efficiency of metabolizable energy utilization at the 5% level (group 6), while mitochondrial ATP synthesis was significantly depressed in both the 2% and the 5% TRANS groups. A parallelism was observed between t,t18:2 incorporation in liver mitochondria, reduced mitochondrial oxidative function and depressed energetic efficiency. The experiments indicated that t,t18:2 exerted a significantly negative effect on energy utilization at 1.0 and 2.5% levels in the diet even when fed with relatively high concentrations of linoleate.

Adenosine Triphosphate↗

PubMed1993

Effect of total parenteral nutrition on liver mitochondrial function in mature rats.

To evaluate the effects of TPN on the hepatic function, the changes in hepatic energy charge levels, oxidative and phosphorylative activities of mitochondria and serum transaminase were studied, using male Sprague-Dawley rats 240 to 250 g in weight. The rats were randomized into three groups. The first group (TPN-V group, n = 6) was infused with TPN solution via the right jugular vein. The number of calories of TPN solution infused daily was adjusted to provide each rat with 80 kcal/kg/day on the 1st day, 160 kcal/kg/day on the 2nd day and 240 kcal/kg/day on the 3rd day. After the 4th day, 240 kcal/kg/day was given to both groups. The second group (TPN-G group, n = 5) was infused with the same solution via an intragastric route and was given the same calories as the TPN-V group. The third group (control group, n = 6) was given a chow diet with the same calories as the TPN group. At the 13th day, all groups were sacrificed, and the hepatic energy charge (EC) and phosphorylation rate (PR) of hepatic mitochondria were measured, and liver function tests were done. PR was 101.2 +/- 5.0 nmol/mg protein/min in control group, 120.8 +/- 2.7 in TNP-G group and 136.5 +/- 6.2 in TPN-V group. EC was 0.906 +/- 0.006, 0.889 +/- 0.008, 0.831 +/- 0.010, respectively. The liver function tests of all group were normal. In both TPN groups, despite evidence that liver function tests were normal, enhanced mitochondrial phosphorylative activity was observed during the early stage of TPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗