title: The effects of fatty acyl CoA esters on the formation of prostaglandin and arachidonoyl-CoA formed from arachidonic acid in rabbit kidney medulla microsomes.
abstract: Under physiological conditions, small amounts of free arachidonic acid (AA) are released from membrane phospholipids, and cyclooxygenase (COX) and acyl CoA synthetase (ACS) competitively act on this fatty acid to form prostaglandins (PGs) and arachidonoyl-CoA (AA-CoA). We have previously shown that palmitoyl-CoA (PA-CoA) shifts AA away from the COX pathway into the ACS pathway in rabbit kidney medulla at a low concentration of AA (5 microM, close to the physiological concentration of substrate). In the present study, we investigated the effects of stearoyl (SA)-, oleoyl (OA)- and linoleoyl (LA)- CoAs on the formation of PG and AA-CoA from 5microM AA in rabbit kidney medulla microsomes. The kidney medulla microsomes were incubated with 5microM [(14)C]-AA in 0.1 M-Tris/HCl buffer (pH 8.0) containing cofactors of COX (reduced glutathione and hydroquinone) and cofactors of ACS (ATP, MgCl(2)and CoA). After incubation, PG (as total PGs), AA-CoA and residual AA were separated by selective extraction using petroleum ether and ethyl acetate. SA- and OA-CoAs increased AA-CoA formation with a reduction of PG formation, as well as PA-CoA. On the other hand, LA-CoA decreased formation of both PG and AA-CoA. These results suggest that fatty acyl CoA esters can be regulators of PG and AA-CoA formation in kidney medulla under physiological conditions.
authors.affiliation: Department of Hygienic Chemistry, Osaka University of Pharmaceutical Sciences, 4-20-1 Nasahara, Takatsuki, Osaka 569-1094, Japan. sakuma@oysun01.oups.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Sakuma
authors.forename: Y
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Y
authors.initials: Y
authors.lastname: Katoh
authors.forename: A
authors.initials: A
authors.lastname: Kitao
authors.forename: T
authors.initials: T
authors.lastname: Fujita
mesh_terms: D000214:Acyl Coenzyme A / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001095:Arachidonic Acids / Q000378:metabolism*; D002250:Carbon Radioisotopes; D007679:Kidney Medulla / Q000648:ultrastructure; D019787:Linoleic Acid / Q000378:metabolism; D008297:Male; D008861:Microsomes / Q000378:metabolism*; D019301:Oleic Acid / Q000378:metabolism; D011453:Prostaglandins / Q000096:biosynthesis*; D011817:Rabbits; D013229:Stearic Acids / Q000378:metabolism
chemical_list: D000214:Acyl Coenzyme A; D001095:Arachidonic Acids; D002250:Carbon Radioisotopes; D011453:Prostaglandins; D013229:Stearic Acids; D019301:Oleic Acid; C031183:stearic acid; D019787:Linoleic Acid