The adipose tissue metabolism: role of testosterone and dehydroepiandrosterone.
Testosterone (T) and dehydroepiandrosterone (DHEA) are fat-reducing hormones, even though they exert this effect by different mechanisms. In particular, T inhibits lipid uptake and lipoprotein-lipase (LDL) activity in adipocytes, and stimulates lipolysis by increasing the number of lipolytic beta-adrenergic receptors. An indirect sign of these effects is the decrease of adipocyte leptin production. Lastly, T inhibits differentiation of adipocyte precursor cells. Concerning DHEA, this hormone does not seen to have any of T effects; however, DHEA stimulates resting metabolic rate (RMR) and lipid oxidation, and enhances glucose disposal, by increasing the expression of GLUT-1 and GLUT-4 on fat cell plasma membrane. The insulin-like effect of DHEA would be associated to a decrease of plasma insulin concentrations and, thus, to an increase of the molar ratio between lipolytic hormones and insulin. Noteworthy, the fat-reducing effect of both T and DHEA seems to be more evident at the level of visceral adipose tissue.
De Pergola
G
G
Istituto di Clinica Medica, Endocrinologia e Malattie Metaboliche dell'Universita di Bari, Policlinico di Bari, Italy. depergio@iqsnet.it
D017667:Adipocytes / Q000187:drug effects; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D003687:Dehydroepiandrosterone / Q000494:pharmacology / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008066:Lipolysis / Q000187:drug effects; D008071:Lipoprotein Lipase / Q000037:antagonists & inhibitors; D013739:Testosterone / Q000494:pharmacology / Q000502:physiology*
D013739:Testosterone; D003687:Dehydroepiandrosterone; D008071:Lipoprotein Lipase; D005947:Glucose