Muscle stimulant, skeletal

One possible mechanism responsible for the abiHty of trenbolone acetate to stimulate skeletal muscle hypertrophy may be through enhanced proliferation and differentiation of satelHte ceUs as the result of increased sensitivity to insuHn-Hke growth factor-I (IGE-1) and fibroblast growth factor (43). 

Mechanism of Action. P-Agonists stimulate skeletal muscle growth by accelerating rates of fiber hypertrophy and protein synthesis, but generally do not alter muscle DNA content in parallel with the increases in protein accretion (133—135). This is in contrast to the effects of anaboHc steroids and ST on skeletal muscle growth. Both of the latter stimulate fiber hypertrophy and muscle protein synthesis, but also increase muscle DNA content coincident with increased protein accretion. Whether the P-agonists decrease muscle protein degradation is equivocal. 

Nakielny, S., Cohen, P., Wu, J., and Sturgill, T. (1992a). MAP kinase activator from insulin-stimulated skeletal muscle is a protein serine/threonine kinase. EMBO S. 11 2123-2129. 

Macrocytic anaemia. An anaemia in which abnormally large red blood cells are present. Myasthenia gravis. A disease in which the nerves fail to stimulate skeletal muscle, characterized by profound muscular weakness. 

A metal-dye detection system has been developed that permits picomolar-range HPLC analysis of inositol phosphates from nonradioactively labeled tissues (Mayr, 1990), and was applied for the determination of masses of inositol phosphates in resting and stimulated skeletal muscles (Mayr and Thieleczek, 1991). 

Dimethylphenylpipazinium stimulates the autonomic ganglia tetraethylammonium and hexamethonium block the autonomic ganglia phenyltrimethylammonium stimulates skeletal muscle end plates decamethonium produces neuromuscular blockage and d-tubocurarine blocks the autonomic ganglia and the motor fiber end plates. 

Barnard, W., Bower, J., Brown, M.A., Murphy, M. and Austin, L. (1994) Leukemia inhibitory factor (LIF) infusion stimulates skeletal muscle regeneration after injury injured muscle expresses LIF mRNA. J. Neurol. Sci. 123 108-113. 

In the area of functional electrical stimulation, skeletal muscle transfers (myoplasty) combined with electrical stimulation have been advocated to provide contractile function that augments or replaces impaired organ function (Grandjean et al., 1996). Clinical investigation of dynamic car-diomyoplasty for the treatment of heart failure and dynamic myoplasty for treatment of fecal or urinary incontinence is already under investigation. 

Carbamylcholine (carbachol) (first stimulates skeletal muscle, then blocks neuromuscular transmission)... 

Fujita S, Glynn BL, Timmerman KL et al. (2009) Supraphysiological hyperinsuhnaemia is necessary to stimulate skeletal muscle protein anabolism in older adults evidence of a true age-related insulin resistance of musde protein metabolism. Diabetologia 52, 1889-1898. 

The absorption of sulfonylureas from the upper gastrointestinal tract is faidy rapid and complete. The agents are transported in the blood as protein-bound complexes. As they are released from protein-binding sites, the free (unbound) form becomes available for diffusion into tissues and to sites of action. Specific receptors are present on pancreatic islet P-ceU surfaces which bind sulfonylureas with high affinity. Binding of sulfonylureas to these receptors appears to be coupled to an ATP-sensitive channel to stimulate insulin secretion. These agents may also potentiate insulin-stimulated glucose transport in adipose tissue and skeletal muscle. 

The myocytes of smooth muscle are approximately 100 to 500 p,m in length and only 2 to 6 p,m in diameter. Smooth muscle contains very few t-tubules and much less SR than skeletal muscle. The Ca that stimulates contraction in smooth muscle cells is predominantly extracellular in origin. This Ca enters the cell through Ca channels in the sarcolemmal membrane that can be opened by electrical stimulation, or by the binding of hormones or drugs. The contraction response time of smooth muscle cells is very slow compared with that of skeletal and cardiac muscle. 

Bradykinin stimulates natriuresis and, through stimulation of prostaglandin synthesis, inhibits the actions of antidiuretic hormone (ADH), thereby inhibiting water retention. Bradykinin further improves insulin sensitivity and cellular glucose utilization of skeletal muscle cells in experimental models. This, however, appears not to be relevant in the clinical context. 

Metformin restrains hepatic glucose production principally by suppression of gluconeogenesis. The mechanisms involve potentiation of insulin action and decreased hepatic extraction of certain gluconeogenic substrates such as lactate. In addition, metformin reduces the rate of hepatic glycogenolysis and decreases the activity of hepatic glucose-6-phosphatase. Insulin-stimulated glucose uptake and glycogenesis by skeletal muscle is increased by metformin mainly by increased... 

S100A1 is the most abundant in the myocardium but is also expressed in brain and other tissues. S100A1 was found to stimulate Ca2+-induced Ca2+-release (CICR) in skeletal muscle terminal cisternae. In the presence of nanomolar Ca2+-concentrations, S100A1 binds to the ryanodine receptor increasing its channel open probability, and was shown to enhance SR Ca2+-release and contractile performance. Several animal models (over expressing S100A1 or S100A1-deficient mice) have... 

Caffeine is a mild to potent CNS stimulant, with the degree of its stimulating effect dependent on the dose administered. Caffeine stimulates the CNS at all levels, including the cerebral cortex, die medulla, and the spinal cord. Caffeine has mild analeptic (respiratory stimulating) activity. Other actions include cardiac stimulation (which may produce tachycardia), dilatation of coronary and peripheral blood vessels, constriction of cerebral blood vessels, and skeletal muscle stimulation. Caffeine also has mild diuretic activity. 

Ketamine (Ketalar) is a rapid-acting general anesthetic. It produces an anesthetic state characterized by profound analgesia, cardiovascular and respiratory stimulation, normal or enhanced skeletal muscle tone, and occasionally mild respiratory depression. Ketamine is used for diagnostic and surgical procedures that do not require relaxation of skeletal muscles, for induction of anesthesia before the administration of other anesthetic drugp, and as a supplement to other anesthetic drags. 

Enflurane (Ethrane) is a volatile liquid anesthetic that is delivered by inhalation. Induction and recovery from anesthesia are rapid. Muscle relaxation for abdominal surgery is adequate, but greater relaxation may be necessary and may require the use of a skeletal muscle relaxant. Enflurane may produce mild stimulation of respiratory and bronchial secretions when used alone Hypotension may occur when anesthesia deepens. 

Hultman, E. Sjoholm, H. (1983b). Electromyogram, force and relaxation time during and after continuous electrical stimulation of human skeletal muscle in situ. J. Physiol. 339, 33-40. 

Hultman, E. Spriet, L.L. (1986). Skeletal muscle metabolism, contraction force and glycogen utilization during prolonged electrical stimulation in humans. J. Physiol. 374,493-501. 

Spriet, L.L., Soderlund, K., Bergstrom, M., Hultman, E. (1987a). Anaerobic energy release in skeletal muscle during electrical stimulation in men. J. Appl. Physiol. 62, 611-615. 

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