RT Journal Article SR Electronic T1 Intranuclear Localization of Hepatic Cytochrome P448 by an Immunochemical Method JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 324 OP 331 VO 16 IS 1 A1 EDWARD BRESNICK A1 DAVID BORAKER A1 BRUCE HASSUK A1 WAYNE LEVIN A1 PAUL E. THOMAS YR 1979 UL http://molpharm.aspetjournals.org/content/16/1/324.abstract AB By means of a combined histochemical-immunological technique, at least a part of the intracellular hepatic cytochrome P448 has been localized within nuclei isolated from 3-methylcholanthrene pretreated rats. In this technique, sections of nuclei are incubated initially with rabbit anti-cytochrome P448, then with goat anti-rabbit immunoglobulin to which β-galactosidase had been chemically coupled. The preparation is then histochemically assayed for β-galactosidase using the histochemical substrate 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside in the presence of an oxidizing agent, nitroblue tetrazolium. A blue pigment is generated at the site of localization of β-galactosidase, and accordingly, of cytochrome P448. When conjugate was employed in which the immunoglobulin was monospecific antibody to cytochrome P450 obtained from the livers of phenobarbital-treated rats, no demonstrable activity was observed within the nuclei obtained from 3-methylcholanthrene pretreated rats. This control adds considerable weight to our argument for the intranuclear localization of at least a portion of the cytochrome P448.