Submitted on December 16, 2006
Accepted on March 26, 2007
The atrial natriuretic peptide- and catecholamine-induced lipolysis and expression of related genes in adipose tissue in hypothyroid and hyperthyroid patients
Jan Polak1*, Cedric Moro2, Eva Klimcakova3, Michaela Kovacikova4, Magda Bajzova4, Michaela Vitkova4, Zuzana Kovacova4, Richard Sotornik5, Michel Berlan6, Nathalie Viguerie6, Dominique Langin7, and Vladimir Stich8
1 Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; Center of Biomedical Sciencies, Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
2 Institut Louis Bugnard IFR31, Université Paul Sabatier, Toulouse, France; Unité de Recherches sur les Obésités, U586, INSERM, Toulouse, France; Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
3 Center of Biomedical Sciencies, Division of Cell and Molecular Biology, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
4 Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
5 2nd Internal Medicine Department, Kralovske Vinohrady Teaching Hospital, Prague, Czech Republic
6 Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; Unité de Recherches sur les Obésités, U586, INSERM, Toulouse, France; Institut Louis Bugnard IFR31, Université Paul Sabatier, Toulouse, France
7 Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; Unité de Recherches sur les Obésités, U586, INSERM, Toulouse, France; Institut Louis Bugnard IFR31, Université Paul Sabatier, Toulouse, France; Centre Hospitalier Universitaire de Toulouse, Toulouse, France
8 Franco-Czech Laboratory for Clinical Research on Obesity, Third Faculty of Medicine, Charles University in Prague, Prague, Czech Republic; 2nd Internal Medicine Department, Kralovske Vinohrady Teaching Hospital, Prague, Czech Republic
* To whom correspondence should be addressed. E-mail: jan.polak{at}lf3.cuni.cz.
Thyroid dysfunction is associated with several abnormalities in intermediary metabolism including impairment of lipolytic response to catecholamines in subcutaneous abdominal adipose tissue (SCAAT). Atrial natriuretic peptide (ANP) is a powerful lipolytic peptide, however, the role of ANP-mediated lipolysis in thyroid disease has not been elucidated.
The aim of this study was to investigate the role of thyroid hormones in the regulation of ANP-induced lipolysis as well as in the gene expression of HSL (hormone sensitive lipase), PDE3B (phosphodiesterase 3B), UCP2 (uncoupling protein 2), NPR-A (natriuretic peptide receptor type A) and 
2AR (2-adrenergic receptor) in SCAAT of hyperthyroid and hypothyroid patients. Gene expression in SCAAT was studied in 13 hypothyroid and 11 hyperthyroid age matched women before and 2-4 months after the normalisation of their thyroid status. A microdialysis study was performed on a subset of 9 hyperthyroid and 10 hypothyroid subjects. ANP- and isoprenaline-induced lipolyses were higher in hyperthyroid subjects, with no differences between the groups following treatment. HSL gene expression was higher in hyperthyroid compared to hypothyroid subjects before treatment, while no difference was observed following treatment. No differences in gene expression of other genes were observed between the two groups. Following treatment, the gene expression of UCP2 decreased in hyperthyroid while the expression of PDE3B decreased in hypothyroid subjects. Conclusion: Thyroid hormones regulate ANP- and isoprenaline-mediated lipolysis in human SCAAT in vivo at a post-receptor level.
