Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.3.1.21 (CPT)
 4,580 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Unequivocal demarcation between immature, nonmigratory yellow eels and migratory silver eels of greater sexual maturity is possible by measuring eye diameter and retinal capillary length, which undergo a 1.5- and 2.3-fold increase during metamorphosis, respectively. Anatomical arrangement of trunk musculature is similar in the two groups except for an increased depth of slow muscle in silver eel. Histochemical analysis reveals a progressive increase in numbers of "displaced" fast fibres within slow muscle of the lateral line triangle in maturing eels, although these are unlikely to affect recruitment pattern of muscle fibre types. Previous studies have suggested greater involvement of fast muscle in locomotion of migratory eels. In contrast, estimates of enzyme activity in fast muscle suggest an inadequate aerobic capacity to fuel sustained activity. Myoglobin content is extremely low, around 0.4 nM g wet wt-1. Prolonged anaerobic metabolism is also discounted as a migratory strategy. Increased energy provision for migration is apparently derived from increased capacity for both aerobic carbohydrate metabolism and mitochondrial fatty acid oxidation within slow muscle of silver eels. Activity of hexokinase (HK) shows a 1.6-fold increase (to 0.51 microM g wet wt-1) and carnitine palmitoyltransferase (CPT) a 3.1-fold increase (to 0.22 microM g wet wt-1 min-1), suggesting a maximal flux through these pathways of 18 and 14 ATP equivalents, respectively. However, the fatty acyl transferase system of skeletal muscle mitochondria displays up to threefold greater activity with palmitoleoyl CoA (C16:1) as substrate than with the usual palmitoyl CoA (C16:0). Slow muscle of silver eel is therefore capable of deriving aerobic energy from free fatty acids and carbohydrate in the ratio 2.3:1. Differences in aerobic enzyme activities are not paralleled by myoglobin content of slow muscle, being 15 and 16 nM g wet wt-1 for yellow and silver eel, respectively. Structural reorganization of muscle fibres during metamorphosis, however, results in a twofold elevation of cytoplasmic myoglobin concentration in silver eel. It would appear that dramatic differences in metabolic capacity between life history stages of eel is required to overcome locomotory inefficiency of yellow eels and to "preadapt" silver eels for migratory activity. This increased locomotory capacity may be amplified by a subsequent training response.
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PMID:Metamorphosis of the American eel, Anguilla rostrata LeSeur: I. Changes in metabolism of skeletal muscle. 395 May 63

Adult patients deficient in carnitine palmitoyltransferase II (CPT II) cannot generate sufficient amounts of energy, which results in rhabdomyolysis and acute renal failure (ARF). Its genetic basis has been recognized; but histopathologic changes, especially electron microscopic changes, have scarcely been described. The study subject is a patient with ARF caused by repetitive nontraumatic rhabdomyolysis. The acylcarnitine profile of serum and enzyme assay on skin fibroblasts confirmed the diagnosis of CPT II deficiency. Renal biopsy specimens were examined microscopically and immunohistochemically. The histological diagnosis was interstitial nephritis with acute tubular necrosis caused by rhabdomyolysis. Myoglobin in tubules was detected by means of immunohistochemistry and electron microscopy. The genetic structure of CPT II was analyzed in the patient and his family. Eight pairs of polymerase chain reaction (PCR) primers were designed to cover the coding region. Each PCR-amplified gene product was subjected to DNA sequencing, which unveiled heterozygosity at the CPT II locus consisting of a deletion of cytosine and thymine at codon 408, resulting in a stop signal at 420, as well as a mutation of arginine to cysteine at codon 631. The frame shift at 408 has never been described before. DNA sequencing of the family showed the deletion mutation from the mother and the point mutation from the father. We describe renopathological findings in a patient with CPT II deficiency associated with rhabdomyolysis, which suggested the pathological role of myoglobin casts in the development of tubular necrosis. Genetic analysis of the patient identified a novel variant of the CPT II gene.
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PMID:Carnitine palmitoyltransferase II deficiency due to a novel gene variant in a patient with rhabdomyolysis and ARF. 1575 83