Premium
In Vitro TNF‐α‐ and Noradrenaline‐Stimulated Lipolysis is Impaired in Adipocytes from Growing Rats Fed a Low‐Protein, High‐Carbohydrate Diet
Author(s) -
Feres Daniel D. S.,
Santos Maísa P.,
Buzelle Samyra L.,
Pereira Mayara P.,
França Suélem A.,
Garófalo Maria A. R.,
Andrade Cláudia M. B.,
Froelich Mendalli,
Almeida Fhelipe J. S.,
Frasson Danúbia,
Chaves Valéria E.,
Kawashita Nair H.
Publication year - 2013
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-013-3809-z
Subject(s) - medicine , endocrinology , lipolysis , adipose triglyceride lipase , hormone sensitive lipase , adipose tissue , biology , lipase , adipocyte , chemistry , corticosterone , hormone , enzyme , biochemistry
Abstract The aim of this study was to investigate tumor necrosis factor alpha (TNF‐α)‐ and noradrenaline (NE)‐stimulated lipolysis in retroperitoneal (RWAT) and epididymal (EAT) white adipose tissue as a means of understanding how low‐protein, high‐carbohydrate (LPHC) diet‐fed rats maintain their lipid storage in a catabolic environment (marked by increases in serum TNF‐α and corticosterone and sympathetic flux to RWAT and EAT), as previously observed. Adipocytes or tissues from the RWAT and EAT of rats fed an LPHC diet and rats fed a control (C) diet for 15 days were used in the experiments. The adipocytes from both tissues of the LPHC rats exhibited lower TNF‐α‐ stimulated lipolysis compared to adipocytes from the C rats. The intracellular lipolytic agents IBMX, DBcAMPc and FSK increased lipolysis in both tissues from rats fed the C and LPHC diets compared to basal lipolysis; however, the effect was approximately 2.5‐fold lower in adipocytes from LPHC rats. The LPHC diet induced a marked reduction in the β 3 and α 2 ‐AR, adipose triglyceride lipase (ATGL) and hormone‐sensitive lipase (HSL) content in RWAT and EAT. The LPHC diet did not affect TNF‐α receptor 1 content but did induce a reduction in ERK p44/42 in both tissues. The present work indicates that RWAT and EAT from LPHC rats have an impairment in the lipolysis signaling pathway activated by NE and TNF‐α, and this impairment explains the reduced response to these lipolytic stimuli, which may be fundamental to the maintenance of lipid storage in LPHC rats.