Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 15-year-old girl with a large accumulation of lipid in the muscle fibers, was suffering from systemic carnitine deficiency. She died in acidosis. The blood carnitine level was normal. At necropsy, carnitine levels were low in skeletal muscles and heart, whilst a normal level was found in the liver. Carnitine palmitoyltransferase II and palmitoyl-CoA synthetase activities were increased, whereas carnitine acetyltransferase, glycerol-3-phosphate dehydrogenase (FAD) and succinate dehydrogenase were decreased. Investigation of blood and skeletal muscle of the family members revealed marked abnormalities in a 7-year old sister who had only minor neurological symptoms. Histochemical investigation revealed abnormal accumulations of lipid between the myofibrils. Carnitine was decreased in her skeletal muscle and blood. Muscular carnitine palmitoyltransferase II and palmitoyl-CoA synthetase were again increased in activity while glycerol-3-phosphate dehydrogenase (FAD) was decreased. The activities of succinate dehydrogenase, carnitine palmitoyltransferase I and glycerol-3-phosphate dehydrogenase (NAD+) were normal. The unexpected normal carnitine level in blood and liver of the deceased patient was attributed to muscle wasting, which was confirmed by the very high blood level of creatine phosphokinase. This fatal case indicates that the fasting condition must be avoided in persons with carnitine deficiency. In crises, glucose supply is necessary since gluconeogenesis may be blocked.
 ...
PMID:Familial carnitine deficiency. A fatal case and subclinical state in a sister. 15 48

Muscle contraction causes an increase in activity of 5'-AMP-activated protein kinase (AMPK). This study was designed to determine whether chronic chemical activation of AMPK will increase mitochondrial enzymes, GLUT-4, and hexokinase in different types of skeletal muscle of resting rats. In acute studies, rats were subcutaneously injected with either 5-aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside (AICAR; 1 mg/g body wt) in 0.9% NaCl or with 0.9% NaCl alone and were then anesthetized for collection and freezing of tissues. AMPK activity increased in the superficial, white region of the quadriceps and in soleus muscles but not in the deep, red region of the quadriceps muscle. Acetyl-CoA carboxylase (ACC) activity, a target for AMPK, decreased in all three muscle types in response to AICAR injection but was lowest in the white quadriceps. In rats given daily, 1 mg/g body wt, subcutaneous injections of AICAR for 4 wk, activities of citrate synthase, succinate dehydrogenase, and malate dehydrogenase were increased in white quadriceps and soleus but not in red quadriceps. Cytochrome c and delta-aminolevulinic acid synthase levels were increased in white, but not red, quadriceps. Carnitine palmitoyl-transferase and hydroxy-acyl-CoA dehydrogenase were not significantly increased. Hexokinase was markedly increased in all three muscles, and GLUT-4 was increased in red and white quadriceps. These results suggest that chronic AMPK activation may mediate the effects of muscle contraction on some, but not all, biochemical adaptations of muscle to endurance exercise training.
 ...
PMID:Activation of AMP-activated protein kinase increases mitochondrial enzymes in skeletal muscle. 1084 39

Cellular parameters of the seminogram have been previously shown to correlate with L-carnitine concentration in the seminal fluid. Carnitine is involved in a variety of metabolic processes playing an important role in maintaining an active oxidative phosphorylation (OXPHOS). Recently, we have found a significant association between the specific activities of the respiratory chain complexes and the seminogram parameters and here we have studied the relationship between the spermatozoa OXPHOS activities and L-carnitine concentration in the seminal plasma. Carnitine, but not prostatic secretions, positive and significantly correlate with mitochondrial respiratory complex activities and the citric acid cycle enzymes citrate synthase and succinate dehydrogenase. It is remarkable that the ratios of the respiratory chain complexes to citrate synthase or succinate dehydrogenase, significant but negatively correlated with L-carnitine concentration. As carnitine in seminal plasma is secreted from the epididymis our results strongly suggest that relationships between carnitine secretion, seminal quality and OXPHOS activities could be because of a parallel response to the same regulatory event.
 ...
PMID:Association between seminal plasma carnitine and sperm mitochondrial enzymatic activities. 1173 14

The skeletal muscle growth rate is a major feature differentiating meat- and laying-type chickens. A large amount of ATP is required during skeletal muscle synthesis, in which mitochondrial energy production capacities play a significant role. Additionally, mitochondria may participate in muscle protein degradation via reactive oxygen species generation. To investigate the differences in mitochondrial energetic characteristics between chickens exhibiting different growth rates, this study evaluated respiratory capacities in response to different types of respiratory substrate, protein abundances, assembly of individual respiratory complexes (I-V) and supercomplexes, and reactive oxygen species generation rates. These characteristics were compared between mitochondria from the breast muscle (M. pectoralis superficialis) of seven-week-old meat- and laying-type male chickens. Blue native polyacrylamide gel electrophoresis analysis revealed that meat-type chickens exhibited a significantly lower protein abundance of complex III (cytochrome bc 1 complex), complex V (F0F1 ATP synthase), and total amount of supercomplexes than did laying-type chickens. There were no differences between chicken types in the respiration rate of mitochondria incubated with either pyruvate/malate or succinate, each of which drives complex I- and complex II-linked respiration. Carnitine palmitoyltransferase-1-dependent and -independent respiration during ATP synthesis and carnitine palmitoyltransferase-2 enzymatic activity were significantly lower in meat-type chickens than in layingtype chickens. For mitochondria receiving pyruvate/malate plus succinate, the reactive oxygen species generation rate and its ratio to the oxygen consumed (the percentage of free radical leak) were also significantly lower in meat-type chickens than in laying-type chickens. These results suggested that the mitochondrial energetic capacities of the breast muscle of meat-type chickens could be lower than those of laying-type chickens at seven weeks of age. Furthermore, the lower reactive oxygen species generation rate in meat-type chickens might have implications for rapid muscle development, which is possibly related to their lower muscle protein degradation rates.
 ...
PMID:Differences in Breast Muscle Mitochondrial Respiratory Capacity, Reactive Oxygen Species Generation, and Complex Characteristics between 7-week-old Meat- and Laying-type Chickens. 3313 33