Effect of 13-hydroperoxyoctadecadienoic acid on the glucosamine synthetase activity in rabbit gastric mucosa.
The effect of 13-hydroperoxyoctadecadienoic acid (13-HPODE) on the activity of glucosamine synthetase, the rate-limiting enzyme of mucus synthesis, in rabbit gastric corporal mucosa was examined. 13-HPODE inhibited the glucosamine synthetase activity at concentrations ranging from 10 to 100 microM. The effect was concentration-dependent, and the concentration required for 50% inhibition was approximately 20 microM. Experiments utilizing Fe2+ and 13-hydroxyoctadecadienoic acid revealed that the inhibitory effect of 13-HPODE on the glucosamine synthetase activity is not due to the alcohol adduct and hydroxyl radical which are expected to be formed from 13-HPODE, and that the hydroperoxyl functional group is a prerequisite. The fact that tert-butyl hydroperoxide exhibited about 50 times weaker inhibition than 13-HPODE indicates the relative specificity of fatty acyl hydroperoxides in the modulation of the glucosamine synthetase activity. These results suggest that 13-HPODE has the potential to modulate the synthesis of gastric mucus by affecting the glucosamine synthetase activity.
Fujita
T
T
Department of Hygienic Chemistry, Osaka University of Pharmaceutical Sciences, Japan.
Sakuma
S
S
Fudemoto
M
M
Watanabe
K
K
Nishida
H
H
Fujimoto
Y
Y
D000818:Animals; D000991:Antithrombins / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005753:Gastric Mucosa / Q000201:enzymology*; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) / Q000187:drug effects* / Q000378:metabolism; D008041:Linoleic Acids / Q000494:pharmacology*; D015227:Lipid Peroxidation; D008054:Lipid Peroxides; D008297:Male; D011817:Rabbits
D000991:Antithrombins; D008041:Linoleic Acids; D008054:Lipid Peroxides; C038649:13-hydroperoxy-9,11-octadecadienoic acid; C024348:13-hydroxy-9,11-octadecadienoic acid; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)