scholarly journals Calcium Mobilisation and CCK Secretion Induced by Modified Fatty Acids and Latex Microspheres Reveal Dual Receptor Mechanisms for Lipid Stimulation of STC‐1 Cells

2003 ◽  
Vol 553 (3) ◽  
pp. 759-773 ◽  
Author(s):  
S. Kazmi ◽  
S. S. Sidhu ◽  
T. J. Donohoe ◽  
M. Wickham ◽  
M. N. Jones ◽  
...  

1990 ◽  
Vol 265 (22) ◽  
pp. 12910-12915
Author(s):  
C D Nobes ◽  
W W Hay ◽  
M D Brand


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 152
Author(s):  
Melita Lončarić ◽  
Ivica Strelec ◽  
Tihomir Moslavac ◽  
Drago Šubarić ◽  
Valentina Pavić ◽  
...  

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.



1972 ◽  
Vol 247 (9) ◽  
pp. 2969-2971 ◽  
Author(s):  
Robert C. Baxter ◽  
Charles W. Carlson ◽  
Burton M. Pogell


1972 ◽  
Vol 128 (5) ◽  
pp. 1057-1067 ◽  
Author(s):  
E. D Saggerson

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.





1995 ◽  
Vol 268 (6) ◽  
pp. R1484-R1490 ◽  
Author(s):  
I. Sarel ◽  
E. P. Widmaier

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).



1982 ◽  
Vol 28 (2) ◽  
pp. 223-230 ◽  
Author(s):  
Adrian J. Cutler ◽  
Robley J. Light

The yeast Candida bogoriensis produced large quantities of an extracellular glycolipid, the diacetyl sophoroside of 13-hydroxydocosanoic acid, when grown on a standard glucose rich medium (3% glucose, 0.15% yeast extract), but not when grown on a low glucose medium (0.5% glucose, 0.4% yeast extract) (A. J. Cutler and R. J. Light. 1979. J. Biol. Chem. 254: 1944–1950). Glucose levels also affected the quantity and distribution of the free fatty acid and triglyceride fractions synthesized by this organism. Cells grown on the low glucose medium contained palmitate and stearate as the major fatty acids in these two fractions, and a 3-h incubation with [1-14C]acetate led primarily to the labeling of these two acids. Cells grown on the standard enriched glucose medium contained relatively less stearate and more behenate than the low glucose grown cells, and the incorporation of [1-14C]acetate into stearate was decreased, while that into behenate was increased.Supplementation of low glucose grown cells with glucose led to a rapid stimulation of fatty acid synthesis, primarily palmitate and stearate in the free fatty acid fraction and stearate in the triglyceride fraction. Total triglyceride began to increase a few hours after supplementation, but synthesis of the extracellular glycolipid, and hence 13-hydroxydocosanoic acid, did not occur until 12–24 h after supplementation. The stimulation by glucose of long chain fatty acid synthesis in C. bogoriensis was therefore a process distinct from the glucose stimulation of palmitate and stearate synthesis, though the two events may be causally related.



1987 ◽  
Vol 40 (4) ◽  
pp. 405
Author(s):  
David Mann ◽  
Audrey M Bersten

The incorporation of long-chain fatty acids into phospholipids has been detected in adipocyte ghosts that were incubated with [1_14 C] stearic, [1_14 C] linoleic or [l_14C] arachidonic acid. Adrenaline and adenosine activated this incorporation within 15 s of exposure of the ghosts to the hormones and the response was dose dependent. Maximum incorporation of labelled linoleic acid occurred at 10-5 M adrenaline and 10-7 M adenosine. The a-agonist phenylephrine and the ~-agonist isoproterenol were also shown to stimulate the incorporation of fatty acid in a dose dependent manner. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine and phosphatidylinositol were each labelled preferentially with linoleic or arachidonic acid. p-Bromophenacylbromide, quinacrine and centrophenoxine inhibited the adrenaline-stimulated incorporation of fatty acids into ghost membrane phospholipids, and p-bromophenacylbromide also reduced the activation of adenylate cyclase by adrenaline. NaF, an activator of adenylate cyclase, like adrenaline, stimulated the incorporation of linoleic acid into ghost membrane phospholipids.



Microbiology ◽  
1985 ◽  
Vol 131 (1) ◽  
pp. 67-72 ◽  
Author(s):  
N. A. JACQUES ◽  
V. L. JACQUES ◽  
A. C. WOLF ◽  
C. L. WITTENBERGER


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