High-fat diet promotes adrenaline production by visceral adipocytes.
PURPOSE
Catecholamines (CA) play a major role in metabolism and immune response. Recent reports showing adipose tissue can synthetize CA enlighten new roles for these amines in obesity. This study aimed to evaluate the expression of both tyrosine hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) and CA content along preadipocytes differentiation, under normal and obesigenic conditions.


METHODS
8-9 week-old male C57BL/6 mice were divided in two groups: one fed with a high-fat diet (HFD) and other with a standard diet (SD) for 20 weeks. Afterwards, both TH and PNMT expression, localization, and CA content in adipocytes, were evaluated.


RESULTS
qPCR results showed no changes for TH and PNMT expression during the differentiation process for visceral and subcutaneous preadipocytes from mice fed with SD. Comparing to SD, HFD increased TH gene expression of subcutaneous preadipocytes and PNMT gene expression of both visceral preadipocytes and adipocytes. HPLC-ED analyses revealed HFD increased visceral adipocytes noradrenaline intracellular content comparing with preadipocytes (p = 0.037). When compared with SD, HFD raised and decreased noradrenaline content, respectively, in visceral adipocytes (p = 0.004) and subcutaneous preadipocytes (p = 0.001). Along the differentiation process, HFD increased visceral adrenaline intracellular content comparing with SD (p < 0.001). HFD increased visceral comparing to subcutaneous adrenaline content for both preadipocytes (p = 0.004) and adipocytes (p = 0.001).


CONCLUSIONS
TH and PNMT expression in adipose tissue is differently modulated in visceral and subcutaneous adipose depots, and seems to depend on diet. Differences observed in visceral adipose CA handling in HFD-fed mice might uncover novel pharmacological/nutritional strategies against obesity and cardiovascular risk.
['Gomes|Andreia|A|', 'Soares|Raquel|R|', 'Costa|Raquel|R|', 'Marino|Franca|F|', 'Cosentino|Marco|M|', 'Malagon|Maria M|MM|', 'Ribeiro|Laura|L|http://orcid.org/0000-0003-1181-9217']
D017667:Adipocytes D000273:Adipose Tissue D000818:Animals D059305:Diet, High-Fat D004195:Disease Models, Animal D004837:Epinephrine D008297:Male D051379:Mice D008810:Mice, Inbred C57BL D009765:Obesity
High-fat diet Catecholamines Adipose tissue Obesity Primary preadipocytes culture