Changes in Cerebral Acyl‐CoA Concentrations Following Ischemia‐Reperfusion in Awake Gerbils

Abstract

Transient global cerebral ischemia affects phospholipid metabolism and features a considerable increase in unesterified fatty acids. Reincorporation of free fatty acids into membrane phospholipids during reperfusion following transient ischemia depends on conversion of fatty acids to acyl-CoAs via acyl-C0A synthetases and incorporation of the acyl group into lysophospholipids.To study the effect of ischemia-reperfusion on brain fatty acid and acyl-CoA pools, the common carotid arteries were tied for 5 mm in awake gerbils, after which the ligatures were released for 5 mm and the animals were killed by microwave irradiation. Twenty percent of these animals (two of 10) were excluded from the ischemia-reperfusion group when it was demonstrated statistically that brain unesterified arachidonic acid concentration was not elevated beyond the range of the control group. Brain unesterified fatty acid concentration was increased 4.4fold in the ischemic-reperfused animals, with stearic acid and arachidonic acid increasing the most among the saturated and polyunsaturated fatty acids, respectively. The total acyl-C0A concentration remained unaffected, indicating that reacylation of membrane lysophospholipids is maintained during recovery. However, there was a substantial increase in the stearoyl-and arachidonoyl-CoA and a marked decrease in palmitoyl-and docosahexaenoyl-C0A. These results suggest that unesterified fatty acid reacylation into phospholipids is reprioritized according to the redistribution in concentration of acyl-CoA molecular species, with incorporation of stearic acid and especially arachidonic acid being favored. Key Words: lschemia-Fatty acid metabolism -Phospholipid metabolism-Acyl-C0A-Brain-Gerbil.

Arachidonic acid incorporation and turnover is decreased in sympathetically denervated rat heart

“…The sample was loaded onto the washed cartridge and the polar components were eluted with 5 ml of 25 mM KH2PO4 buffer (pH 4.9). The acyl-CoA fraction was eluted using a 75:25 (vol/vol) solution of 0.15 ml of 2-propanol and 1 mM acetic acid (39). A portion of this eluent was directly used for separation of the acyl-CoA species on a Phenomenex Luna C-18 (2) column (4.6 ϫ 250 mm), and the individual acyl-CoA values were quantified by UV absorbance measurements.…”

An improved method for tissue long-chain acyl-CoA extraction and analysis

“…Numerous methods have been developed to measure individual long-chain acyl-CoA mass in mammalian tissues (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20). However, most of the reported methods demonstrate low recovery of the acyl-CoA extraction, with recovery ranging from 10% to 45% (7,12,16,21).…”

“…In this paper, we describe modifications of an existing method (17,19) using solid-phase extraction and subsequent HPLC separation of long-chain acyl-CoAs for use with small amounts of tissue ( Ͼ 25 mg). Our modifications increase the recovery of the extraction procedure in excess of 80%, with high reproducibility and significantly improved separation of the most common polyunsaturated and saturated acyl-CoAs.…”

Use of CoA Biosynthesis Modulators and Selenoprotein Model Substance in Correction of Brain Ischemic and Reperfusion Injuries

“…Protective action of pantothenate derivatives have been reported in situations accompanied by oxidative stress, for example, in experimental ischemia-reperfusion of myocardium. It has been shown that antioxidative and membrane-protective effects of the pantothenate derivatives are accompanied by an activation of biosynthesis CoA system and increasing of intracellular level of a free CoA [108,109]. Presumably, the mechanism of cell protection is CoAdependent or realized through CoA-(acyl-CoA)-dependent biochemical reactions, including rise of intracellular glutathione level and maintenance of its redox status.…”

“…This function maintains constant flow of oxidative substrates and their effective using for ATP formation in the citric acid cycle [109,110,111].…”