Growth Hormone Lipid metabolism

Diacylglycerol, on the other hand, is lipid soluble and remains in the lipid bilayer of the membrane. There it can activate protein kinase C (PKC), a very important and widely distributed enzyme which serves many systems through phosphorylation, including neurotransmitters (acetylcholine, a,- and P-adrenoceptors, serotonin), peptide hormones (insulin, epidermal growth hormone, somatomedin), and various cellular functions (glycogen metabolism, muscle activity, structural proteins, etc.), and also interacts with guanylate cyclase. In addition to diacylglycerol, another normal membrane lipid, phos-phatidylserine, is needed for activation of PKC. The DG-IP3 limbs of the pathway usually proceed simultaneously. 

GH has been shown to have many different metabolic effects. Which of these contribute directly to its growth-promoting activity is not clear. The hormone stimulates synthesis of proteins and nucleic acids in a wide range of tissues. It has actions on carbohydrate metabolism, including both diabetogenic and insulin-like actions, and also has effects on lipid metabolism, particularly in man. Overall, GH tends to switch metabolism from utilization of carbohydrate to utilization of fat [14], although there are marked differences between species in the relative importance of actions on different aspects of metabolism. 

Actions of growth hormone on lipid and carbohydrate metabolism... 

GH clearly has effects on carbohydrate and lipid metabolism, the protein-synthetic machinery, expression of specific proteins, and cell differentiation and proliferation. For a hormone concerned with the overall control of somatic growth such a wide spread of activities is potentially physiologically meaningful. It is at least possible that GH mediates these various actions via several different intracellular mechanisms and that it will not be possible to identify any one action as of key importance. 

Human recombinant growth hormone connective tissue, mineral, protein, carbohydrate, and lipid metabolism... 

M.B. Davidson, Effect of growth hormone on carbohydrate and lipid metabolism, Endocrinol. Rev., 1987, 8, 115-131. 

Effect on Lipid Metabolism. The major effect of growth hormone on lipid metabolism is on lipid mobi-... 

In conclusion, the major effect of growth hormone (lipolytic) on lipid metabolism is opposite to that of insulin (stimulates fatty acid deposition). Small doses of growth hormone may elicit an insulinlike effect that is transient, often prolonged by incubation, and replaced by a lipolytic effect. 

Moller N, Jorgensen JOL. Effects of growth hormone on glucose, lipid and protein metabolism in human subjects. Endocr Rev 2009 30 152-77. 

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