Growth hormone increases beta adrenergic receptors

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Tuesday, April 13, 2004 3:37 am Email this article
Growth hormone injections reduce body fat according to several studies. This effect seems to be, at least partly, due to an increase in beta-1 and beta-3 adrenergic receptors, and an increase in adenylate cyclase activity according to a study done on rat tissue (Yang et al, 2004).

Adenylate cyclase is an enzyme that speeds up the chemical reaction of converting ATP to cAMP. An increase in cAMP increases thermogenesis.

Growth hormone also increase hormone-sensitive lipase, which is not necessarily a good thing.

Hormone-sensitive lipase works with other lipases to control the release of fat from fat cells, but this process is also coordinated with fat synthesis according to Haemmerle et al (2003).

Researchers have also found that animals that are deficient of hormone-sensitive lipase become lean, and have favorable changes to blood lipid levels—the have low levls of triglycerides, low levels of very-low-density lipoprotein levels (VLDL), and increased levels of HDL cholesterol.

All of these changes are protective against heart disease according to Haemmerle et al (2003).

But the study is interesting in helping to explain how growth hormone reduces body fat.

REFERENCES

Haemmerle G, Zimmermann R, Zechner R. Letting lipids go: hormone-sensitive lipase. Curr Opin Lipidol. 2003 Jun, 14(3):289-97.

Yang S, Mulder H, Holm C, Eden S. Effects of growth hormone on the function of beta-adrenoceptor subtypes in rat adipocytes. Obes Res. 2004 Feb, 12(2):330-39.

Articles on the same subject can be found here:

• Growth Hormone