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D J Hayes

Publications and source records attributed to D J Hayes.

At least 37 records · Page 2Linked to original sources
PubMed1988

Chronic administration of the oral hypoglycaemic agent diphenyleneiodonium to rats. An animal model of impaired oxidative phosphorylation (mitochondrial myopathy).

Daily subcutaneous administration of the oral hypoglycaemic agent, diphenyleneiodonium at a low dose (1.5 mg/kg body weight) over a 4-5 week period resulted in a normoglycaemic stable animal model of impaired oxidative phosphorylation in the rat. Diphenyleneiodonium specifically inhibits NAD-linked mitochondrial oxidation [Bloxham, Biochem. Soc. Trans. 7, 103 (1979)], and in isolated mitochondrial preparations from heart, soleus and gastrocnemius muscle and liver from treated animals NAD-linked respiration was reduced by 40% or more of mean control values. Brain and kidney mitochondria isolated from the treated group had similar rates of NAD-linked respiration to their respective control values. The activity of NADH-ferricyanide reductase was significantly reduced in all tissues tested, even in the isolated brain and kidney mitochondria where the activity in these tissues was 60-75% of control values. This suggests that at least 40% of Complex I activity must be inhibited before there is a decline in NAD-linked mitochondrial respiration. This paper discusses the use of diphenyleneiodonium as a means of establishing an animal model of the human disease state, termed mitochondrial myopathy.

Administration, Oral↗
PubMed1988

An animal model of mitochondrial myopathy: a biochemical and physiological investigation of rats treated in vivo with the NADH-CoQ reductase inhibitor, diphenyleneiodonium.

Chronic administration of the NADH-CoQ reductase inhibitor, diphenyleneiodonium to rats at two dose levels, 1.0 and 1.5 mg/kg per day, caused a 40% and 60% reduction, respectively, in the in vitro rate of NAD-linked respiration by skeletal muscle mitochondria. At the highest dose, muscle fatigue, lactic acidosis and an over-utilization of phosphocreatine was observed in the gastrocnemius muscle during mild stimulation of 1 Hz frequency. The resynthesis of phosphocreatine following muscle stimulation was about 2 fold slower in the treated animal group. At the low dose, no significant biochemical changes were observed during muscle stimulation at 4 Hz. The results are discussed in terms of skeletal muscle "oxidative reserve", twitch tension maintenance and the relevance to the human diseased state of mitochondrial myopathy.

Acidosis↗
PubMed1988

Human mitochondrial respiratory chain deficiencies.

In this paper selected data from 43 patients with histologically defined mitochondrial myopathies who have been investigated biochemically as previously described are presented. The defect was localized to NADH-ubiquinone oxidoreductase (complex I) in 22 cases and to ubiquinol-cytochrome c oxidoreductase (complex III) in a further 10. Two patients had defects of more than one respiratory enzyme complex and another had a deficiency of H+-ATPase. The lesion was not localized in two cases and in vitro mitochondrial studies were normal in five cases.

Electron Transport Complex III↗
PubMed1987

A 31P-n.m.r. study of the acute effects of beta-blockade on the bioenergetics of skeletal muscle during contraction.

1. The effects of beta-adrenoceptor antagonist administration on skeletal muscle contractile performance and bioenergetics in vivo have been investigated during unilateral sciatic nerve stimulation in the rat. 2. Two muscle stimulation protocols have been used: supramaximal stimulation at 4 Hz, or incremental supramaximal stimulation at 1, 2 and 4 Hz. Changes in high-energy phosphate concentrations were followed using 31P-n.m.r., and gastrocnemius muscle twitch characteristics were monitored continuously. 3. Under all conditions investigated, DL-propranolol administration (2.5 mg/kg body wt.) caused a significant decrease in cyclic AMP concentrations in resting and stimulated gastrocnemius muscle, prevented an increase in heart rate upon muscle stimulation, but did not affect plasma glucose, fatty acid or lactate concentrations in comparison with values obtained in control experiments. 4. Administration of DL-propranolol 5 min or 35 min before unilateral stimulation of 4 Hz had no effect on changes in muscle phosphocreatine, ATP or Pi concentrations, intracellular pH or contractile performance. 5. In contrast, animals receiving DL-propranolol 5 min before unilateral stimulation of 1, 2 and 4 Hz showed a significant deterioration in gastrocnemius muscle tension development during 2 and 4 Hz stimulation compared with control animals. Concurrent with this change in contractile performance was a higher muscle concentration of phosphocreatine, a lower concentration of Pi and no significant change in intramuscular pH compared with control experiments. 6. The changes in muscle performance and bioenergetics observed during the incremental stimulation protocol were not observed when D-propranolol was administered and could be completely circumvented by a short period of muscle stimulation of 4 Hz prior to initiation of the incremental stimulation protocol. 7. Mechanisms are discussed which may account for the failure of gastrocnemius muscle to generate the expected force during the incremental stimulation protocol in the presence of beta-blockade.

Adenine Nucleotides↗
PubMed1987

An unusual metabolic myopathy: a malate-aspartate shuttle defect.

Studies on a 27-year-old man with a 3-year history of exercise-induced muscle pain, passage of red urine and elevated serum creatine kinase are described. Histological examination of a biopsy from quadriceps revealed non-specific myopathic changes with occasional clusters of subsarcolemmal mitochondria. The phosphorylase stain was normal. Phosphorous nuclear magnetic resonance (NMR) spectroscopy studies of gastrocnemius and flexor digitorum superficialis muscles showed no abnormalities at rest. During aerobic exercise there was an abnormally rapid decrease in phosphocreatine concentration but the pH remained within the normal range. There was a build-up of phosphomonoester (probably glucose 6-phosphate), usually indicative of a block in glycolysis. However, a primary defect in the glycolytic pathway seemed unlikely because muscle acidified normally during ischaemic exercise. Recovery from exercise was unusual in that phosphocreatine resynthesis and inorganic phosphate disappearance followed similar prolonged time courses (in control subjects the rate of inorganic phosphate disappearance was about twice as fast as the rate of phosphocreatine resynthesis). The transport of inorganic phosphate into the mitochondria appeared to be delayed. These slow recovery data suggested that oxidative metabolism was impaired. However, with all substrates tested, isolated muscle mitochondria had rates of oxygen uptake that were similar to control values, thereby ruling out a primary defect in mitochondrial respiration. A system involving several mitochondrial transport systems, the malate-aspartate shuttle, was measured. The activity in the patient's isolated mitochondria was less than 20% of the activity present in samples from control subjects. This patient is the only one so far reported with a defect involving the malate-aspartate shuttle system.

Adult↗
PubMed1986

An investigation of arterial insufficiency in the rat hindlimb. Correlation of skeletal muscle bloodflow and glucose utilization in vivo.

Muscle bloodflow and the rate of glucose uptake and phosphorylation were measured in vivo in rats 7 days after unilateral femoral artery ligation and section. Bloodflow was determined by using radiolabelled microspheres. At rest, bloodflow to the gastrocnemius, plantaris and soleus muscles of the ligated limb was similar to their respective mean contralateral control values; however, bilateral sciatic nerve stimulation at 1 Hz caused a less pronounced hyperaemic response in the muscles of the ligated limb, being 59, 63 and 49% of their mean control values in the gastrocnemius, plantaris and soleus muscles respectively. The rate of glucose utilization was determined by using the 2-deoxy[3H]glucose method [Ferré, Leturque, Burnol, Penicaud & Girard (1985) Biochem. J. 228, 103-110]. At rest, the rate of glucose uptake and phosphorylation was statistically significantly increased in the gastrocnemius and soleus muscles of the ligated limb, being 126 and 140% of the mean control values respectively. Bilateral sciatic nerve stimulation at 1 Hz caused a 3-5-fold increase in the rate of glucose utilization by the ligated and contralateral control limbs; furthermore, the rate of glucose utilization was significantly increased in the muscles of the ligated limb, being 140, 129 and 207% of their mean control values respectively. For the range of bloodflow to normally perfused skeletal muscle at rest or during isometric contraction determined in the present study, a linear correlation between the rate of glucose utilization and bloodflow can be demonstrated. Applying similar methods of regression analysis to glucose utilization and bloodflow to muscles of the ligated limb reveals a similar linear correlation. However, the rate of glucose utilization at a given bloodflow is increased in muscles of the ligated limb, indicating an adaptation of skeletal muscle to hypoperfusion.

Animals↗
PubMed1986

An investigation of arterial insufficiency in rat hindlimb. A combined 31P-n.m.r. and bloodflow study.

A small animal model of arterial insufficiency is presented which involves unilateral femoral artery ligation and section. Invoked alterations in metabolism and perfusion of the affected muscle mass have been investigated 12 h, 4, 7 and 14 days post-ligation by 31P-n.m.r. and microsphere infusion, both at rest and during isometric muscle contraction at 1 Hz. At rest, the concentration of phosphocreatine was similar to the mean control value (36.0 +/- 1.0 mM) from 4 days post-ligation, but was significantly lower at 12 h (28.5 +/- 3.6 mM). Inorganic phosphate concentrations were significantly elevated for 7 days post-ligation. No significant differences were noted in intramuscular pH. Upon stimulation of the affected muscle mass, a time-dependent improvement in phosphocreatine utilization was observed such that 14 days post-ligation phosphocreatine utilization was not significantly different from mean control values. A similar amelioration was noted for the contraction-induced fall in intramuscular pH. At rest, no significant differences in bloodflow to the muscles of the ligated limb compared with the unaffected contralateral limb were observed. However, isometric contraction of the affected muscle mass resulted in a markedly reduced hyperaemic response 12 h post-ligation. Thereafter, a time-dependent improvement in tissue perfusion during stimulation was observed which paralleled the improvements in phosphocreatine utilization and intramuscular pH changes. The results presented are discussed with respect to the interrelationship between oxygen delivery, high energy phosphate utilization and force maintenance.

Animals↗
PubMed1986

An investigation of arterial insufficiency in rat hindlimb. An enzymic, mitochondrial and histological study.

A small animal model of arterial insufficiency has been used to investigate enzymic alterations in the gastrocnemius, plantaris and soleus muscles of the hypoperfused limb. At 7 days after induction of arterial insufficiency by unilateral femoral artery ligation, there were significant increases in the maximal activities of hexokinase, phosphorylase and 6-phosphofructokinase, whereas the activities of citrate synthase and 2-oxoglutarate dehydrogenase remained unchanged. Similar increases in hexokinase, phosphorylase and 6-phosphofructokinase were still apparent 8-10 weeks after unilateral artery ligation, although only hexokinase remained significantly higher than contralateral control values. No enhancement of oxidative enzyme activities was observed. The results are discussed in relation to the conflicting findings reported by other groups investigating enzymic adaptations in patients with arterial insufficiency.

Animals↗
PubMed1985

Biochemical adaptation in the skeletal muscle of rats depleted of creatine with the substrate analogue beta-guanidinopropionic acid.

Rats were fed on a diet containing 1% beta-guanidinopropionic acid (GPA), a creatine substrate analogue, for 6-10 weeks to deplete their muscle of creatine. This manipulation was previously shown to give a 90% decrease in [phosphocreatine] in skeletal and cardiac muscle and a 50% decrease in [ATP] in skeletal muscle only. Maximal activities of creatine kinase and of representative enzymes of aerobic and anaerobic energy metabolism were measured in the superficial white, medial and deep red portions of the gastrocnemius muscle, in the soleus and plantaris muscle and in the heart. Fast-twitch muscles were smaller in GPA-fed animals than in controls, but the size of the soleus muscle was unchanged. The activities of aerobic enzymes increased by 30-40% in all fast-twitch muscle regions except the superficial gastrocnemius, but were unchanged in the soleus muscle. The activities of creatine kinase and phosphofructokinase decreased by 20-50% in all skeletal-muscle regions except the deep gastrocnemius, and the activity of glycogen phosphorylase generally paralleled these changes. There were no significant changes in the activities of any of the enzymes measured in the heart. The glycogen content of the gastrocnemius-plantaris complex was increased by 185% in GPA-fed rats. The proportion of Type I fibres in the soleus muscle increased from 81% in control rats to 100% in GPA-fed rats, consistent with a previous report of altered isometric twitch characteristics and a decrease in the maximum velocity of shortening in this muscle [Petrofsky & Fitch (1980) Pflugers Arch. 384, 123-129]. We conclude that fast-twitch muscles adapt by a combination of decreasing diffusion distances, increasing aerobic capacity and decreasing glycolytic potential. Slow-twitch muscles decrease glycolytic potential and become slower, thus decreasing energy demand. These results suggest that persistent changes in the [phosphocreatine] and [ATP] are alone sufficient to alter the expression of enzyme proteins and proteins of the contractile apparatus, and that fibre-type-specific thresholds exist for the transformation response.

Animals↗
PubMed1985

A comparison of in vivo catalysis by creatine kinase in avian skeletal muscles with different fibre composition.

The maximum activity of creatine kinase in vitro is similar in the pectoralis major muscle of the chicken and the duck. However, the flux (phosphocreatine to ATP) as measured by 31P saturation transfer NMR in vivo is almost 2-fold higher in the duck. This apparent discrepancy can be accounted for by the differences in the cytosolic free ADP concentrations in resting muscle.

Adenosine Diphosphate↗
PubMed1985

Experimentally induced defects of mitochondrial metabolism in rat skeletal muscle. Biological effects of the mitochondrial uncoupling agent 2,4-dinitrophenol.

Infusion of dinitrophenol intra-arterially into rat hind limb caused an irreversible failure of isometric twitch tension and the induction of a severe progressive contracture. Metabolite analysis of muscle in which the twitch response had grossly fatigued revealed low levels of ATP and phosphocreatine together with lactate accumulation. Studies using 31P-n.m.r. confirmed the decrease in ATP and creatine phosphate concentrations and indicated a fall in intracellular pH. It is concluded that dinitrophenol-induced myopathy does not represent a good model for the human mitochondrial myopathic condition as has been previously suggested.

2,4-Dinitrophenol↗
PubMed1985

Experimentally induced defects of mitochondrial metabolism in rat skeletal muscle. Biological effects of the NADH: coenzyme Q reductase inhibitor diphenyleneiodonium.

An animal model for the human condition of mitochondrial myopathy has been established and characterized physiologically and biochemically. The NADH: coenzyme Q reductase inhibitor diphenyleneiodonium [Bloxham (1979) Biochem. Soc. Trans. 7, 103-106] was either infused acutely in vivo into rat hind limb or injected chronically into rats. Both modes of delivery resulted in a reduced muscle oxidative capacity and increased fatigue. Analysis of muscle metabolites by h.p.l.c. and 31P-n.m.r. indicated that ATP concentrations were similar to control values during periods of stimulation and these were maintained by the phosphocreatine pool. During the recovery period after muscle stimulation in the experimental animals the muscle pH remained depressed and the rate of phosphocreatine synthesis was markedly delayed as compared with controls. Factors thought to be involved in the fatigue response are discussed in relation to this model.

Animals↗
PubMed1985

A mitochondrial encephalomyopathy. A combined 31P magnetic resonance and biochemical investigation.

A 15-year-old girl presented with recurrent encephalopathic episodes, epilepsy, myopathy and chronic lactic acidosis. A muscle biopsy revealed the presence of ragged red fibres and mitochondria with paracrystalline inclusions. Biochemical studies on freshly isolated skeletal muscle mitochondria demonstrated a deficiency of NADH-CoQ reductase activity. Investigation of her gastrocnemius muscle at rest by phosphorus nuclear magnetic resonance displayed a reduced phosphocreatine concentration with elevated levels of inorganic phosphate and ADP. Abnormalities were also apparent in her brain spectrum. It is therefore possible that the mitochondrial defect present in skeletal muscle is also being expressed in the brain.

Adolescent↗
PubMed1984

Mitochondrial myopathies: disorders of the respiratory chain and oxidative phosphorylation.

Mitochondrial myopathies are a clinical condition characterized by muscle weakness and fatigue in which the primary defect is localized at the level of the mitochondria. Microscopic examination shows accumulations of mitochondria at the fibre periphery (ragged red fibres) and in some cases mitochondrial paracrystalline inclusions. The spectrum of different mitochondrial defects so far described is reviewed and data from cases investigated in this laboratory are described. The first case was a 17-year-old boy with a multisystem disorder whose muscle mitochondria showed low respiratory activity with all substrates, which doubled in the presence of uncoupler. Further investigation showed that the mitochondrial ATPase activity was only 6% of normal. The next cases were a mother and daughter who showed a typical lipid storage myopathy. The latter was treated successfully with oral carnitine but the myopathy persisted. Mitochondrial investigations indicated a low respiratory activity with NAD-linked substrates but normal activity with succinate and ascorbate + TMPD. A defect in the NADH-CoQ reductase section of the respiratory chain was pinpointed possibly at an iron-sulphur centre. The fourth and fifth cases were two sisters who exhibited no lipid storage myopathy but whose mitochondrial activity was low with NAD-linked substrates but normal with succinate. Again a defect in the NADH-CoQ reductase (complex I) of the respiratory chain was determined. They were also investigated using 31P-NMR. It was found after exercise that their muscle creatine phosphate levels took seven times longer to return to pre-exercise concentrations than control subjects. These results are discussed with respect to the synthesis of mitochondrial proteins and the influence that both the mitochondrial and nuclear DNA have on this process.

Adolescent↗
PubMed1984

A new mitochondrial myopathy. Biochemical studies revealing a deficiency in the cytochrome b-c1 complex (complex III) of the respiratory chain.

A 20-year-old Chilean girl presented with lifelong ptosis and fatiguable weakness which was initially thought to be due to a congenital myasthenic syndrome. Studies of an intercostal muscle biopsy showed normal endplate morphology, abundant acetylcholinesterase activity and a normal number of junctional acetylcholine receptors as determined by radiochemical assay, but a high proportion of the muscle fibres contained large peripheral aggregations of abnormal mitochondria. Biochemical investigation of mitochondria isolated from the vastus lateralis muscle demonstrated a hitherto unreported respiratory chain deficiency localized to complex III.

Adult↗