Journal of Dental Research, Vol 65, 39-43, Copyright © 1986 by International & American Associations for Dental Research Online Journals
Aryl hydrocarbon hydroxylase activity in rat submandibular glands
K. Murakami, T. Ishikawa, T. Shimosato, M. Noshiro, S. Hayashi and K. Okuda
The activities of aryl hydrocarbon hydroxylase and 7-ethoxycoumarin
O-de-ethylase in the rat submandibular gland, both of which are normally
very low, were increased about 10- and 25-fold, respectively, by
administration of 3-methylcholanthrene. The increased activity of aryl
hydrocarbon hydroxylase was inhibited by 7,8-benzoflavone but little if any
by metyrapone and SKF-525A. The submandibular gland aryl hydrocarbon
hydroxylase was also inhibited by antibodies elicited against rat liver
cytochrome P-448 and NADPH-cytochrome P-450 reductase, respectively, and
slightly by anti-cytochrome b 5 antibody, suggesting that submandibular
gland aryl hydrocarbon hydroxylase resembles that of the liver, not only in
the immunochemical properties of cytochrome P-450 involved, but also in the
entire enzyme complex, including the electron transferring system.
Cofactor(s) required by aryl hydrocarbon hydroxylase in submandibular gland
was NADPH, whereas NADH sustained the reaction at a much slower rate (about
20%). NADH showed some additive action when added with NADPH.
