scholarly journals The mechanism of stimulation of respiration by fatty acids in isolated hepatocytes.

1990 ◽  
Vol 265 (22) ◽  
pp. 12910-12915
Author(s):  
C D Nobes ◽  
W W Hay ◽  
M D Brand
Keyword(s):  
Fatty Acids ◽  
Isolated Hepatocytes ◽  
Stimulation Of

scholarly journals Evidence from studies employing radioactively labelled fatty acids that the stimulation of flux through the diacylglycerol pool is an early action of vasopressin on hepatocytes

1987 ◽  
Vol 245 (1) ◽  
pp. 211-216 ◽  
Author(s):  
L B Pickford ◽  
A J Polverino ◽  
G J Barritt
Keyword(s):  
Fatty Acids ◽  
Arachidonic Acid ◽  
Phosphatidic Acid ◽  
Isolated Hepatocytes ◽  
Maximal Increase ◽  
Maximal Stimulation ◽  
Early Action ◽  
Palmitic Acids ◽  
Stimulation Of ◽  
In Cells

1. In isolated hepatocytes prelabelled with [14C]-arachidonic, -stearic, -linoleic, -oleic or -palmitic acids, vasopressin increased the amount of radioactivity present in diacylglycerols. The largest increase was observed in cells labelled with arachidonic or stearic acids. 2. In cells prelabelled with [14C]- or [3H]-arachidonic acid, the onset of the increase in radioactivity in diacylglycerols induced by vasopressin was slow, the increase was partly dependent on the presence of extracellular Ca2+, and was associated with an increase in radioactivity present in phosphatidic acid which was more rapid in onset. Vasopressin decreased the amount of [3H]arachidonyl-phosphatidylinositol 4,5-bisphosphate, but the magnitude of this decrease was less than 10% of the observed increase in radioactivity in [3H]arachidonyl-diacylglycerol. 3. The concentration of vasopressin which gave half-maximal increase in [14C]arachidonyl-diacylglycerol at low extracellular Ca2+ was 10-fold higher than that which gave half-maximal stimulation of 45Ca2+ efflux. Phenylephrine, but not glucagon, also increased the amount of [14C]arachidonyl-diacylglycerol. 4. It is concluded that an early action of vasopressin on the liver cell is to increase the flux of carbon from phospholipids, including the phosphoinositides, to diacylglycerols.

scholarly journals Lipoxygenase Inhibition by Plant Extracts

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 152
Author(s):  
Melita Lončarić ◽  
Ivica Strelec ◽  
Tihomir Moslavac ◽  
Drago Šubarić ◽  
Valentina Pavić ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Inflammatory Reactions ◽  
Long Term Storage ◽  
Food Properties ◽  
Lipoxygenase Inhibition ◽  
Plant Families ◽  
Term Storage ◽  
Stimulation Of

Lipoxygenases are widespread enzymes that catalyze oxidation of polyunsaturated fatty acids (linoleic, linolenic, and arachidonic acid) to produce hydroperoxides. Lipoxygenase reactions can be desirable, but also lipoxygenases can react in undesirable ways. Most of the products of lipoxygenase reactions are aromatic compounds that can affect food properties, especially during long-term storage. Lipoxygenase action on unsaturated fatty acids could result in off-flavor/off-odor development, causing food spoilage. In addition, lipoxygenases are present in the human body and play an important role in stimulation of inflammatory reactions. Inflammation is linked to many diseases, such as cancer, stroke, and cardiovascular and neurodegenerative diseases. This review summarized recent research on plant families and species that can inhibit lipoxygenase activity.

scholarly journals Stimulation of the Neutral Activity of Rabbit Liver Fructose 1,6-Diphosphatase by Fatty Acids

1972 ◽  
Vol 247 (9) ◽  
pp. 2969-2971 ◽  
Author(s):  
Robert C. Baxter ◽  
Charles W. Carlson ◽  
Burton M. Pogell
Keyword(s):  
Fatty Acids ◽  
Rabbit Liver ◽  
Neutral Activity ◽  
Stimulation Of

scholarly journals The regulation of glyceride synthesis in isolated white-fat cells. The effects of palmitate and lipolytic agents

1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Free Fatty Acids ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Fat Cells ◽  
Glyceride Synthesis ◽  
Glucose Incorporation ◽  
High Concentrations ◽  
Stimulation Of

1. 0.5mm-Palmitate stimulated incorporation of [U-14C]glucose into glyceride glycerol and fatty acids in normal fat cells in a manner dependent upon the glucose concentration. 2. In the presence of insulin the incorporation of 5mm-glucose into glyceride fatty acids was increased by concentrations of palmitate, adrenaline and 6-N-2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate up to 0.5mm, 0.5μm and 0.5mm respectively. Higher concentrations of these agents produced progressive decreases in the rate of glucose incorporation into fatty acids. 3. The effects of palmitate and lipolytic agents upon the measured parameters of glucose utilization were similar, suggesting that the effects of lipolytic agents are mediated through increased concentrations of free fatty acids. 4. In fat cells from 24h-starved rats, maximal stimulation of glucose incorporation into fatty acids was achieved with 0.25mm-palmitate. Higher concentrations of palmitate were inhibitory. In fat cells from 72h-starved rats, palmitate only stimulated glucose incorporation into fatty acids at high concentrations of palmitate (1mm and above). 5. The ability of fat cells to incorporate glucose into glyceride glycerol in the presence of palmitate decreased with increasing periods of starvation. 6. It is suggested that low concentrations of free fatty acids stimulate fatty acid synthesis from glucose by increasing the utilization of ATP and cytoplasmic NADH for esterification of these free fatty acids. When esterification of free fatty acids does not keep pace with their provision, inhibition of fatty acid synthesis occurs. Provision of free fatty acids far in excess of the esterification capacity of the cells leads to uncoupling of oxidative phosphorylation and a secondary stimulation of fatty acid synthesis from glucose.

Stimulation of steroidogenesis in cultured rat adrenocortical cells by unsaturated fatty acids

1995 ◽  
Vol 268 (6) ◽  
pp. R1484-R1490 ◽  
Author(s):  
I. Sarel ◽  
E. P. Widmaier
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Lipid Homeostasis ◽  
Control Mechanisms ◽  
Adrenocortical Cells ◽  
Stimulatory Action ◽  
Apparent Lack ◽  
Naturally Occurring ◽  
Oleic And Linoleic Acids ◽  
Stimulation Of

The hypothesis that the stimulatory action of free fatty acids (FFA) in the hypothalamic-pituitary-adrenocortical (HPA) axis occurs in part at the adrenal cortex was evaluated. Pathophysiological concentrations of oleic and linoleic acids, but not stearic or caprylic acid, stimulated steroidogenesis from cultured rat adrenocortical cells (concentrations eliciting 50% of maximal responses, approximately 60 and 120 microM, respectively), with a latency of 90 min. Maximal stimulation of steroidogenesis by both acids was < 50% of that produced by adrenocorticotropic hormone (ACTH) and was blocked by cycloheximide. The maximal steroidogenic response to ACTH was inhibited approximately 50% by oleic acid. The actions of oleic and linoleic acids were not associated with an increase in adenosine 3',5'-cyclic monophosphate (cAMP) secretion but appeared to require intracellular oxidation. None of the lipids influenced cell viability or corticosterone radioimmunoassay. The latency of the steroidogenic response, the putative requirement for intracellular oxidation, and the apparent lack of involvement of cAMP suggest a mechanism of action of FFA distinct from that of ACTH, yet still requiring protein synthesis. It is concluded that the modulation of steroidogenesis by these abundant naturally occurring lipids may be an important component of the control mechanisms within the HPA pathway in disorders of lipid homeostasis (e.g., obesity, starvation, or diabetes).

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