Monoclonal antibodies directed characterization of epidermal and hepatic cytochrome P-450 isozymes induced by skin application of therapeutic crude coal tar.
A single application of crude coal tar (CCT) solution (USP) to the skin of neonatal rats was shown to induce epidermal and hepatic cytochrome P-450(P-450)-dependent monooxygenase activities. To further characterize the induction response, in this study we have utilized highly specific monoclonal antibodies (MoAb) 1-7-1, 2-66-3, and 1-98-1 directed against highly purified rat liver P-450s induced by 3-methyl-cholanthrene, phenobarbital and ethanol, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of hepatic microsomes prepared from CCT-treated animals showed a significant increase in the coomassie blue stainable proteins in the P-450 region; however, this was not evident in epidermal microsomes. Immunoblot analysis of epidermal and hepatic microsomes with MoAb 1-7-1 revealed strong immunoprecipitin bands in both tissues. MoAb 2-66-3 showed significant immunoreactivity only with hepatic microsomes. Interestingly, CCT treatment resulted in suppression of immunoreactivity with MoAb 1-98-1 in hepatic microsomes. MoAb 1-7-1 and 2-66-3 exhibited concentration-dependent inhibitory effects in aryl hydrocarbon hydroxylase and 7-ethoxycoumarin-O-deethylase activities induced by CCT application. MoAb 1-7-1 was substantially more effective in this respect. Epidermal and hepatic microsomes prepared from CCT-treated rats showed significantly greater metabolism of benzo(a)pyrene (BP). MoAb 1-7-1 and MoAb 2-66-3 inhibited BP metabolism in both the tissues. However, MoAb 1-7-1 was more inhibitory in this regard as compared to MoAb 2-66-3. These studies indicate that topical application of therapeutic CCT to the skin of neonatal rats results in induction of P-450 isozyme c in epidermis and isozymes b and c in liver, and that this induction is associated with the suppression of P-450 isozyme j in liver.
Khan
W A
WA
Department of Dermatology, University Hospitals of Cleveland, Case Western Reserve University, Ohio.
Park
S S
SS
Gelboin
H V
HV
Bickers
D R
DR
Mukhtar
H
H
D000287:Administration, Topical; D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D001564:Benzo(a)pyrene / Q000378:metabolism; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D003033:Coal Tar / Q000494:pharmacology*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004817:Epidermis / Q000201:enzymology* / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism*; D008099:Liver / Q000201:enzymology* / Q000378:metabolism; D008861:Microsomes / Q000201:enzymology; D010105:Oxygenases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012867:Skin
D000911:Antibodies, Monoclonal; D007527:Isoenzymes; D001564:Benzo(a)pyrene; D003033:Coal Tar; D003577:Cytochrome P-450 Enzyme System; D010105:Oxygenases