Pertussis toxin (PT), a protein produced by Bordetella pertussis, was studied for its effect on lipolysis in isolated rat epididymal adipocytes. Exposure of adipocytes to pertussis toxin resulted in a significant increase in cyclic AMP levels and lipolysis after a lag of 1-2 hr. Both the maximal rate of lipolysis and the time lag (beyond 1 hr) were PT concentration-dependent. Heat treatment (95...

Siberian hamsters (Phodopus sungorus) exhibit a naturally occurring, reversible seasonal obesity with body fat peaking in long "summerlike" days (LDs) and reaching a nadir in short "winterlike" days (SDs). These SD-induced decreases in adiposity are mediated largely via sympathetic nervous system (SNS) innervation of white adipose tissue (WAT), as indicated by increased WAT norepinephrine (NE) ...

Lipolysis involves the sequential breakdown of fatty acids from triacylglycerol and is increased during energy stress such as exercise. Adipose triglyceride lipase (ATGL) is a key regulator of skeletal muscle lipolysis and perilipin (PLIN) 5 is postulated to be an important regulator of ATGL action of muscle lipolysis. Hence, we hypothesized that non-genomic regulation such as cellular localiza...

Curcumin is natural polyphenol with beneficial effects on lipid and glucose metabolism and this study aimed to investigate the effects of curcumin on lipolysis and hepatic insulin resistance. Endoplasmic reticulum (ER) stress and lipolysis signaling in adipose and FFA influx, lipid deposits, and glucose production in liver were examined. Palmitate challenge and high-fat diet feeding evoked ER s...

OBJECTIVE Adiponectin is an adipocyte-derived hormone that sensitizes insulin and improves energy metabolism in tissues. This study was designed to investigate the direct regulatory effects of adiponectin on lipid metabolism in adipocytes. RESEARCH DESIGN AND METHODS Basal and hormone-stimulated lipolysis were comparatively analyzed using white adipose tissues or primary adipocytes from adipo...

Fatty acid translocase (FAT)/CD36 has been extensively studied for its role in facilitating fatty acid uptake. Recent findings have also demonstrated that this protein regulates adipocyte lipolysis and may modulate fatty acid reesterification. As FAT/CD36 has been shown to control the expression of genes involved in fatty acid oxidation in adipocytes, we reasoned that this protein might also co...

To ascertain whether chylomicron constituents would be transferred to low density lipoprotein (LDL, d 1.019-1.063 g/ml) and high density lipoprotein (HDL, d 1.063-1.21 g/ml) density fractions during lipolysis in the absence of other lipoproteins, the in vitro effect of bovine milk lipoprotein lipase on human thoracic duct lymph chylomicrons in the presence of albumin was examined. In incubation...

Prior to hibernation, the brown bear (Ursus arctos) exhibits unparalleled weight gain. Unlike humans, weight gain in bears is associated with lower levels of circulating free fatty acids (FFA) and increased insulin sensitivity. Understanding how free-ranging brown bears suppress lipolysis when gaining weight may therefore provide novel insight toward the development of human therapies. Blood an...

The effects of insulin on the suppression of lipolysis are neither fully understood nor quantified. We examined a variety of mathematical models analogous to the minimal model of glucose disposal (MMG) to quantify the combined influence of insulin on lipolysis and glucose disposal during an insulin-modified frequently sampled intravenous glucose tolerance test. The tested models, which include ...

Hagström-Toft, Eva, Staffan Enoksson, Erik Moberg, Jan Bolinder, and Peter Arner. b-Adrenergic regulation of lipolysis and blood flow in human skeletal muscle in vivo. Am. J. Physiol. 275 (Endocrinol. Metab. 38): E909–E916, 1998.— Little is known about the regulation of catecholaminestimulated lipolysis in human skeletal muscle. Therefore, b-adrenergic regulation of lipolysis and blood flow was...