Some ultrastructural observations on the denervated skeletal muscle of frog.

The frog skeletal muscle resists atrophy for a long time after denervation. If, however, the entry of the nerve is prevented for more than 3.5 months, small muscle portions, sometimes containing nucleus, are sequestered from the parent muscle fibre. The basal lamina does not dissociate from these detached muscle portions.     

Alkaline phosphatase activity in normal and denervated skeletal muscle

Summary Changes in the specific activity of alkaline phosphatase in the normal and denervated skeletal muscle have been studied both histochemically as well as biochemically for a maximum period of 8 weeks of its postnatal development. In the normal muscle, a heterogenous population of fibres with respect to the enzyme distribution is observed. Relatively higher levels of enzyme in the denervated muscle and also the proliferation of extrafibrillar connective tissue in the diseased muscle show its specific association with the lytic processes.     

Alanine and aspartate aminotransferases in normal and denervated skeletal muscle

Activities of alanine and aspartate aminotransferases are maintained during the first 5 weeks of growth, but decrease subsequently in normal chick gastrocnemii. In sciatectomized muscles, a 5-fold elevation in these enzymes reveals increased utilization of amino acids as a compensatory metabolic support during denervation atrophy.     

Alanine and aspartate aminotransferases in normal and denervated skeletal muscle

Summary Activities of alanine and aspartate aminotransferases are maintained during the first 5 weeks of growth, but decrease subsequently in normal chick gastrocnemii. In sciatectomized muscles, a 5-fold elevation in these enzymes reveals increased utilization of amino acid as a compensatory metabolic support during denervation atrophy.     

Some ultrastructural observations on the denervated skeletal muscle of frog

Summary The frog skeletal muscle resists atrophy for a long time after denervation. If, however, the entry of the nerve is prevented for more than 3.5 months, small muscle portions, sometimes containing nucleus, are sequestered from the parent muscle fibre. The basal lamina does not dissociate from these detached muscle portions.     

Calcium sensitivity of succinate and pyruvate dehydrogenases in the denervated amphibian skeletal muscle

Zusammenfassung Es wird nachgewiesen, dass die Aktivität von Succinat Dehydrogenase und von Pyruvat Dehydrogenase in Extrakten normaler und denervierter Muskulatur durch Ca⁺⁺ im pH-Bereich von 5,8 bis 7,8 in verschiedenem Ausmass erhöht bzw. erniedrigt wird.     

Porcine skeletal muscle for physiological studies.

The common digital extensor (lateral head) is one of the few porcine muscles of convenient dimensions for in vitro studies of intact cells. Its removal and use in physiological studies are described.     

Purine nucleotide cycle as a possible anaplerotic process in rat skeletal muscle

Summary The intermediates of the purine nucleotide cycle (PNC) stimulated pyruvate oxidation by isolated skeletal muscle mitochondria in a system containing mitochondria and cytosol from rat skeletal muscle. Thus, in skeletal muscle the PNC might be involved in the anaplerotic supply of tricarboxylic acid cycle intermediates.Acknowledgment. This work was supported by a grant from the Polish Academy of Science within the project MR II.1.2.4.     

Fatty acid unsaturation and cholesterol content in normal and denervated muscle

Riassunto In numero di iodio dei grassi estratti da muscoli denervati è diminuito e il contenuto di colesterolo risulta aumentato. L'aumento è assai spiccato se si confrontano gli estratti lipidici delle frazioni microsomali.     

The response of human skeletal muscle tissue to hypoxia

Hypoxia refers to environmental or clinical settings that potentially threaten tissue oxygen homeostasis. One unique aspect of skeletal muscle is that, in addition to hypoxia, oxygen balance in this tissue may be further compromised when exercise is superimposed on hypoxia. This review focuses on the cellular and molecular responses of human skeletal muscle to acute and chronic hypoxia, with emphasis on physical exercise and training. Based on published work, it is suggested that hypoxia does not appear to promote angiogenesis or to greatly alter oxidative enzymes in skeletal muscle at rest. Although the HIF-1 pathway in skeletal muscle is still poorly documented, emerging evidence suggests that muscle HIF-1 signaling is only activated to a minor degree by hypoxia. On the other hand, combining hypoxia with exercise appears to improve some aspects of muscle O₂ transport and/or metabolism.     

The acetylcholine content and choline-acetyltransferase activity in human skeletal muscle

Riassunto Sono descritte le tecniche per la determinazione della ACH e attività CHA nel muscolo umano normale. I risultati indicano che il rapporto fra capacità sintetizzante e neurormone è più alto in muscoli con maggior impegno funzionale.     

Potentials in mammalian skeletal muscle from collagenase-treated tissue.

Transmembrane potentials were recorded from skeletal muscle fibres dissected with the aid of collagenase perfusion. Collagenase treatment had little or no effect on the action or resting potentials.