GH effects on muscle

Re: GH effects on muscle

Posted by: jboldman

Skeletal muscle as a metabolic target for growth hormone.Jorgensen JO, Vestergaard ET, Krag M, Nielsen C, Moller L, Gormsen L, Jessen N.
Medical Department M, Aarhus University Hospital, Aarhus, Denmark.

Skeletal muscle is the major constituent of lean body mass and a major determinant of energy expenditure, both at rest and during physical activity. Growth hormone (GH), in turn, influences muscle mass as well as energy expenditure. GH substitution in adults increases muscle mass by 5-10%, but part of this is attributed to rehydration. In addition, GH increases resting energy expenditure independently of muscle mass, via mechanisms that may include increased conversion of the thyroid hormones thyroxine (T4) to tri-iodothyronine (T3) and stimulation of skeletal muscle blood flow. In addition, GH regulates substrate metabolism in muscle and, in particular, antagonizes insulin-stimulated glucose disposal. This effect is linked to increased free fatty acid flux, but the molecular mechanisms remain unclear. During fasting, GH-induced insulin resistance may be favourable by reducing the demand for gluconeogenesis from protein. In the postprandial phase, however, GH exposure may compromise glucose tolerance via the same mechanisms. Understanding the mechanisms by which GH antagonizes insulin-stimulated glucose disposal in muscle is an important future research field, with implications for a variety of clinical conditions ranging from malnutrition to obesity and type 2 diabetes mellitus.

Am I understanding this right?
HGH shouldn't be taken p/w because

quote:

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antagonizes insulin-stimulated glucose disposal

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Re: Re: GH effects on muscle

Posted by: motomatt

Am I understanding this right?
HGH shouldn't be taken p/w because

BACKGROUND: Two molecular forms of human GH (hGH) have been shown to be biologically active. The 20 kDa form has been reported to have weaker diabetogenic and lipolytic actions than the 22 kDa form. OBJECTIVE: To analyze the carbohydrate metabolism of 20 kDa and 22 kDa hGH, using the adult male spontaneous dwarf rat (SDR), which is GH deficient. DESIGN: SDRs were given 20 kDa or 22 kDa hGH in doses of 125 microg/rat or 500 microg/rat, or saline, for 10 days, and their weight, serum IGF-I, glucose, insulin, leptin and body composition were measured. RESULTS: Weight and serum IGF-I increased both in the 20 kDa and 22 kDa groups, but IGF-I concentrations were significantly lower in the 20 kDa group than in the 22 kDa group. Serum glucose was not increased by either 20 kDa or 22 kDa hGH, whereas insulin was significantly increased after the higher dose of the 22 kDa hGH. Although blood concentrations of leptin were decreased by both 20 kDa and 22 kDa hGH, values were lower in the high-dose 20 kDa group than in the group given the same dose of 22 kDa hGH. Both forms of GH increased the percentage body water and body protein content, and decreased the percentage of body fat by the same degree. The observation that the higher dose of the 22 kDa hGH increased insulin concentrations without changing blood glucose demonstrates that this concentration of the hormone induces insulin resistance, whereas the same dose of 20 kDa hGH does not. CONCLUSIONS: The results can be interpreted to indicate that the higher dose of the 22 kDa hGH has diabetogenic activity, as reported previously, whereas the 20 kDa hGH has lower diabetogenic activity. The 20 kDa form of hGH may therefore be more useful in treating adult GH deficiency, especially those with severe obesity.

Thanks for post dr frankenstein
How do you tell if HGH is 20 kDa or 22 kDa, ?