Effect of 13-hydroperoxyoctadecadienoic acid on the supply of arachidonic acid for prostaglandin synthesis from arachidonoyl-CoA mediated by the cytosolic or microsomal acyl-CoA hydrolase in rabbit kidney medulla.
The effects of 13-hydroperoxyoctadecadienoic acid (13-HPODE) on the cytosolic or microsomal acyl-CoA hydrolase (ACH) activity in rabbit kidney medulla and on the ACH-mediated prostaglandin (PG) formation from arachidonoyl-CoA (AA-CoA) were examined. 13-HPODE (10, 20, and 50 microM) had no effect on the cytosolic ACH activity but significantly inhibited the activity of the microsomal enzyme (43-57% inhibition). PG formation was measured as follows: AA-CoA (20 nmol) was preincubated with the cytosolic or microsomal fraction (as the source of ACH) in the presence or absence of 13-HPODE for 5 min at 37 degrees C, followed by incubation with the microsomal fraction (as the source of PG-synthesizing enzymes), hydroquinone and reduced glutathione for 5 min at 37 degrees C, and the PGs formed were measured by HPLC, with use of 9-anthryldiazomethane for derivatization. 13-HPODE reduced the PG formation when the microsomal fraction, but not the cytosolic fraction, was used as the source of ACH (10, 20, and 50 microM; 28-55% inhibition). These results suggest that 13-HPODE may modulate PG levels in rabbit kidney medulla by inhibiting the microsomal ACH activity.
Sakuma
S
S
Department of Hygienic Chemistry, Osaka University of Pharmaceutical Sciences, Japan. sakuma@oysun01.oups.ac.jp
Fujimoto
Y
Y
Yoshimura
M
M
Saeki
K
K
Mukai
A
A
Akimoto
M
M
Fujita
T
T
D000214:Acyl Coenzyme A / Q000378:metabolism*; D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007679:Kidney Medulla / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D008041:Linoleic Acids / Q000494:pharmacology*; D008054:Lipid Peroxides / Q000494:pharmacology*; D008297:Male; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology*; D010170:Palmitoyl-CoA Hydrolase / Q000378:metabolism*; D011448:Prostaglandin Antagonists / Q000494:pharmacology; D011453:Prostaglandins / Q000096:biosynthesis*; D011817:Rabbits
D000214:Acyl Coenzyme A; D008041:Linoleic Acids; D008054:Lipid Peroxides; D011448:Prostaglandin Antagonists; D011453:Prostaglandins; C038649:13-hydroperoxy-9,11-octadecadienoic acid; D016718:Arachidonic Acid; D010170:Palmitoyl-CoA Hydrolase