Carnitine is a physiological cellular constituent that favors intracellular fatty acid transport, whose role on platelet function and O(2) free radicals has not been fully investigated. The aim of this study was to seek whether carnitine interferes with arachidonic acid metabolism and platelet function. Carnitine (10-50 microM) was able to dose dependently inhibit arachidonic acid incorporation...

After preliminary screening, Mortierella alpina and Mortierella elongata were compared with respect to arachidonic acid content. M. alpina ATCC 16266 produced 2.1 g of arachidonic acid per liter in media containing 10% glucose while the highest percentage of arachidonic acid in lipid (43.3%) was observed at a glucose concentration of 2%. Arachidonic acid content in lipids increased to 66% durin...

[H] Arachidonic acid is released after stimulation of suspended and attached neutrophils. The arachidonic acid release in attached cells is more than in suspended cells. This release is rapid with the increase of incubation time and dose depended. The Fmet-Leu-Phe (FMLP) potentiates [H] arachidonic acid release in attached cells pretreated with LPS and serum. [H] arachidonic acid release was le...

Low (nonaggregating) concentrations of collagen that potentiate platelet aggregation did not induce the formation of measurable amount of malondialdehyde (MDA) but released small but significant amounts of radioactivity from 14C-arachidonic acid-labeled platelets. A major portion of the radioactive compounds released by nonaggregating concentrations of collagen existed as arachidonic acid and a...

Whereas insulin does not stimulate hexose transport in polymorphonuclear leukocytes, we recently reported that C5a causes the leukocytes to take up 2-[(3)H]deoxyglucose. We now find that fMet-Leu-Phe, in a concentration-related manner with an EC(50) (concentration producing 50% of stimulatory activity) of 1.2 nM, causes a 5.5-fold stimulation of deoxyglucose uptake. Moreover, arachidonic acid (...

Although arachidonic acid causes rabbit platelet aggregation and the release of granule contents in suspensions of washed platelets when used in concentrations of approximately 50-300 microM, higher concentrations (500 microM) cause neither aggregation nor release. Suspensions of platelets from rabbits wee exposed to arachidonic acid (250 microM) for 15 min, allowed to recover in the presence o...

Electrochemical oxidation of some selected catechol derivatives, using cyclic voltammetry, in the presence of different 2-aryl-1,3-indandiones as nucleophiles, resulted in electrochemical synthesis of new 1,3- indandione derivatives in an undivided cell in good yield and purity. A Michael addition mechanism was proposed for the formation of the analogs based on the reaction conditions which wer...

Increased arachidonic acid release occurred during activation of catecholamine secretion from cultured bovine adrenal medullary chromaffin cells. The nicotinic agonist 1,1-dimethyl-4- phenylpiperazinium (DMPP) caused an increased release of preincubated [3H]arachidonic acid over a time course which corresponded to the stimulation of catecholamine secretion. Like catecholamine secretion, the DMP...

We examined the mechanism of arachidonic acid-induced vasodilation in rat small mesenteric arteries and determined the primary arachidonic acid metabolites produced by these arteries. Responses to arachidonic acid in small mesenteric arteries from Sprague-Dawley rats were investigated in vitro in the presence or absence of endothelium or after pretreatment with inhibitors of nitric oxide (NO), ...

When cultured human umbilical vein endothelial cells are supplemented with linoleic acid, the arachidonic acid content of the cellular phospholipids is reduced approximately 35%. Most of the fatty acid compositional change occurs during the first 24 h. One factor responsible for this effect is the inability of the endothelial cells to convert appreciable amounts of linoleic to arachidonic acid,...