Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024591 (malignant hyperthermia)
 2,353 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mitochondria were isolated from biopsies of the biceps femoris muscle of Danish landrace pigs. Three groups of animals were compared: (1) normal pigs; (2) pigs that were homozygous with respect to the gene Hal(n)/Hal(n) coding for the porcine malignant hyperthermia syndrome; and (3) heterozygote animals. A newly developed micro-method for preparation and assaying of small quantities of intact mitochondria was employed. With this technique mitochondria from biopsies weighing less than 100 mg were examined with respect to cytochrome content as well as phosphorylating and respiratory activities, including the nonphosphorylating exo-NADH oxidase activity. The mitochondria, prepared in a yield of 48%, showed high respiratory activities with tricarboxylic acid-cycle intermediates and pyruvate, and somewhat lower activity with palmitoyl-carnitine as substrate. The ATP synthase activity was about 1000 micromol ATP/min per g of protein and the maximal respiratory activity approx. 700 micromol of O2/min per g of protein. No differences among the three groups of animals were detected, except for the exo-NADH oxidase activities, which were 43, 78 and 107 micromol of O2/min per g of protein in the groups of normal, heterozygous and homozygous animals respectively. It is concluded that the exo-NADH oxidase activity may be a genetic manifestation of malignant hyperthermia and may play a significant role in the heat production characteristic of the syndrome.
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PMID:Characterization of mitochondria from pig muscle: higher activity of exo-NADH oxidase in animals suffering from malignant hyperthermia. 861 44

2-[(14)C]oxoglutarate uptake in resting cells of Staphylococcus aureus 17810S occurs via two kinetically different systems: (1) a secondary, electrogenic 2-oxoglutarate:H(+) symporter (K(m)=0.105 mM), energized by an electrochemical proton potential (Delta mu H(+)) that is generated by the oxidation of endogenous amino acids and sensitive to ionophores, and (2) a Delta mu H(+)-independent facilitated diffusion system (K(m)=1.31 mM). The 2-oxoglutarate transport system of S. aureus 17810S can be classified as a new member of the MHS (metabolite:H(+) symporter) family. This transporter takes up various dicarboxylic acids in the order of affinity: succinate = malate > fumarate > 2-oxoglutarate > glutamate. Energy conservation with 2-oxoglutarate was studied in starved cells of strain 17810S. Initial transport of 2-oxoglutarate in these cells is energized by Delta mu H(+) generated via hydrolysis of residual ATP. Subsequent oxidation of the accumulated 2-oxoglutarate generates Delta mu H(+) for further, autoenergized transport of this 2-oxoacid and also for Delta mu H(+)-linked resynthesis of ATP. In the cadmium-sensitive S. aureus 17810S, Cd(2+) accumulation strongly inhibits energy conservation with 2-oxoglutarate at the level of Delta mu H(+) generation, without direct blocking of the 2-oxoglutarate transport system or ATP synthase complex. In the cadmium-resistant S. aureus 17810R, Cd(2+) does not affect energy conservation due to its extrusion by the Cd(2+) efflux system (Cd(2+)-ATPase of P-type), which prevents Cd(2+) accumulation.
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PMID:2-Oxoglutarate transport system in Staphylococcus aureus. 1147 14

Skeletal muscles are metabolically active and have market value in meat-producing farm animals. A better understanding of biological pathways affecting energy metabolism in skeletal muscle could advance the science of skeletal muscle. In this study, comparative pathway-focused gene expression profiling in conjunction with muscle fiber typing were analyzed in skeletal muscles from Duroc, Pietrain, and Duroc-Pietrain crossbred pigs. Each breed type displayed a distinct muscle fiber-type composition. Mitochondrial respiratory activity and glycolytic and oxidative enzyme activities were comparable among genotypes, except for significantly lower complex I activity in Pietrain pigs homozygous-positive for malignant hyperthermia syndrome. At the transcriptional level, lactate dehydrogenase B showed breed specificity, with significantly lower expression in Pietrain pigs homozygous-positive for malignant hyperthermia syndrome. A similar mRNA expression pattern was shown for several subunits of oxidative phosphorylation complexes, including complex I, complex II, complex IV, and ATP synthase. Significant correlations were observed between mRNA expression of genes in focused pathways and enzyme activities in a breed-dependent manner. Moreover, expression patterns of pathway-focused genes were well correlated with muscle fiber-type composition. These results stress the importance of regulation of transcriptional rate of genes related to oxidative and glycolytic pathways in the metabolic capacity of muscle fibers. Overall, the results further the breed-specific understanding of the molecular basis of metabolic enzyme activities, which directly impact meat quality.
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PMID:Molecular changes in mitochondrial respiratory activity and metabolic enzyme activity in muscle of four pig breeds with distinct metabolic types. 2675 28