Elevated FFA concentrations have been shown to reproduce some of the metabolic abnormalities of obesity. It has been hypothesized that visceral adipose tissue lipolysis releases excess FFAs into the portal vein, exposing the liver to higher FFA concentrations. We used isotope dilution/hepatic vein catheterization techniques to examine whether intra-abdominal fat contributes a greater portion of...

OBJECTIVE Free fatty acids (FFA) are commonly elevated in diabetes and obesity and have been shown to impair nitric oxide (NO) production by endothelial cells. However, the signaling pathways responsible for FFA impairment of NO production in endothelial cells have not been characterized. Insulin receptor substrate-1 (IRS-1) regulation is critical for activation of endothelial nitric oxide synt...

In order to know the mode of action of norepinephrine in enhanced utilization of plasma free fatty acids (FFA) in cold acclimation, albumin-bound 14C-palmitate was infused intravenously at a constant rate into cold- and warm-acclimated rats under pentobarbital anesthesia with and without norepinephrine infusion. Rectal temperature, CO2 output and plasma FFA, from which the rates of FFA uptake a...

BACKGROUND Elevated free fatty acid (FFA) levels are known to impair aortic elastic function. In obesity, FFA levels are elevated and aortic distensibility (AD) reduced in a pattern that predominantly affects the distal aorta. Despite this, the role of FFAs in obesity-related aortic stiffness remains unclear. METHODS AND RESULTS Using vascular MRI, we aimed to determine if (1) FFA level corre...

We investigated heredity-independent effects of increased physical activity and aerobic fitness on skeletal muscle free fatty acid (FFA) uptake, perfusion, and their heterogeneity at rest and during exercise. Also, the relationship between local skeletal muscle FFA uptake and perfusion was studied. Nine young adult male monozygotic twin pairs with significant difference in physical activity [22...

A sensitive micromethod for the colorimetric determination of free fatty acids (FFA) in plasma has been developed. FFA are extracted with chloroform-heptane-methanol with silicic acid being added to eliminate interfering phospholipids. Diphenylcarbazide containing diphenylcarbazone has been chosen as color-developing reagent, since the chromophore formed in the presence of FFA-Cu complex is sta...

Body fat deposition and excess free fatty acid (FFA) metabolism contribute to dyslipidemia and the adverse health consequences of obesity. Individuals with upper body obesity have impaired functioning of adipocytes, the primary fatty acid storage site. Excess visceral fat is strongly associated with impaired suppression of FFA release in response to insulin, as well as with hypertriglyceridemia...

OBJECTIVE Overfeeding is associated with insulin resistance. Studies on animals suggest this is likely due to disruption of fatty acid metabolism and increased plasma free fatty acid (FFA) availability during the night. We tested the hypothesis that overfeeding induces insulin resistance and increases nocturnal but not daytime plasma FFA availability in human subjects. DESIGN AND METHODS We m...

OBJECTIVE Obesity, insulin resistance, and diabetes disproportionately affect African-American (AA) women. Abnormal adipose tissue free fatty acid (FFA) release is associated with these conditions. Resting energy expenditure (REE) and sex predict FFA release in Caucasians, but whether this is true in AA is unknown. The sex-specific relationships between FFA release, REE, and race was compared. ...

We have shown that both free fatty acids (FFA) and triglycerides (TG) increase expression of plasminogen activator inhibitor type 1 (PAI-1) in vivo and in vitro. To determine signaling mechanisms responsible, HepG2 cells were exposed to FFA, emulsified TG, or the combination. The combination of FFA and TG increased PAI-1 to a greater extent than either agent alone (fold induction: 0.45mM FFA 1....