Involvement of prostaglandin E2 in ornithine decarboxylase induction by a tumor-promoting agent, 7-bromomethylbenz[a]anthracene, in mouse epidermis.
A single topical application of 7-bromomethyl-benz[a]anthracene (BrMBA; 200 nmol) to mouse skin induced epidermal ornithine decarboxylase (ODC) activity. A topical application of indomethacin (1.2 mumol), a cyclooxygenase inhibitor, 10 min before BrMBA application markedly inhibited BrMBA-caused ODC induction. Concurrent application of prostaglandin E2 (PGE2; 0.1-1.5 mumol) reversed the inhibitory effect of indomethacin. Without indomethacin, PGE2 suppressed BrMBA-caused ODC induction. The results indicate that PGE2 has dual actions on the BrMBA-caused ODC induction, i.e. PGE2 plays an essential role in ODC induction caused by BrMBA, whereas exogenous PGE2 rather suppressed BrMBA-caused ODC induction.
Yamamoto
S
S
Department of Pharmacology, School of Medicine, Keio University, Tokyo, Japan.
Jiang
H
H
Otsuka
C
C
Kato
R
R
D000818:Animals; D001551:Benz(a)Anthracenes / Q000494:pharmacology*; D015232:Dinoprostone / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D007213:Indomethacin / Q000494:pharmacology*; D051379:Mice; D009955:Ornithine Decarboxylase / Q000096:biosynthesis*; D012867:Skin / Q000201:enzymology*
D001551:Benz(a)Anthracenes; C001903:7-bromomethylbenzanthracene; D009955:Ornithine Decarboxylase; D015232:Dinoprostone; D007213:Indomethacin