TY - JOUR
T1 - Immunological evidence for phenobarbital-stimulated synthesis of cytochrome P-450 in primary cultures of chick embryo hepatocytes
AU - Oron, Lea
AU - Bar-Nun, Shoshana
N1 - Funding Information:
We wish to thank Ms. Zehava Zimmer for her excellent technical assistance. This work was supported by the Israeli Academy of Science, Basic Research Fund.
PY - 1984/11/13
Y1 - 1984/11/13
N2 - The induction of cytochrome P-450 by phenobarbital was studied in primary cultures of chick embryo hepatocytes. The rate of the de novo synthesis of the induced form of cytochrome P-450 was measured directly and specificially, using form-specific anti-cytochrome antibodies that quantitatively immunoprecipitated this form from the radiolabeled hepatocytes. Additionally, the steady-state levels of the cytochrome were estimated spectrophotometrically and electrophoretically. In the presence of phenobarbital the synthesis of cytochrome P-450PB by cultured hepatocytes was markedly accelerated. Furthermore, the same cytochrome P-450PB form was induced by phenobarbital in vivo in chicken liver and in the cultured chick embryo hepatocytes. Their identity was judged from immunological and electrophoretic properties of these induced cytochromes. Immunological cross-reactivity was also detected between the cytochrome P-450PB forms from chick embryo hepatocytes and from adult rat liver. The immunological cross-reactivity observed between the phenobarbital-induced cytochrome P-450 forms from different species was not observed between the different cytochrome forms with the same liver (Thomas, P.E., Reik, L.M., Ryan, D.E. and Levin, W. (1981) J. Biol. Chem. 256, 1044-1052). Implications as to the evolutionary origin of the different cytochrome forms are discussed.
AB - The induction of cytochrome P-450 by phenobarbital was studied in primary cultures of chick embryo hepatocytes. The rate of the de novo synthesis of the induced form of cytochrome P-450 was measured directly and specificially, using form-specific anti-cytochrome antibodies that quantitatively immunoprecipitated this form from the radiolabeled hepatocytes. Additionally, the steady-state levels of the cytochrome were estimated spectrophotometrically and electrophoretically. In the presence of phenobarbital the synthesis of cytochrome P-450PB by cultured hepatocytes was markedly accelerated. Furthermore, the same cytochrome P-450PB form was induced by phenobarbital in vivo in chicken liver and in the cultured chick embryo hepatocytes. Their identity was judged from immunological and electrophoretic properties of these induced cytochromes. Immunological cross-reactivity was also detected between the cytochrome P-450PB forms from chick embryo hepatocytes and from adult rat liver. The immunological cross-reactivity observed between the phenobarbital-induced cytochrome P-450 forms from different species was not observed between the different cytochrome forms with the same liver (Thomas, P.E., Reik, L.M., Ryan, D.E. and Levin, W. (1981) J. Biol. Chem. 256, 1044-1052). Implications as to the evolutionary origin of the different cytochrome forms are discussed.
KW - (Chick embryo hepatocyte)
KW - Cytochrome P-450 synthesis
KW - Phenobarbital stimulation
UR - http://www.scopus.com/inward/record.url?scp=0021687653&partnerID=8YFLogxK
U2 - 10.1016/0167-4889(84)90085-5
DO - 10.1016/0167-4889(84)90085-5
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AN - SCOPUS:0021687653
SN - 0167-4889
VL - 805
SP - 291
EP - 299
JO - BBA - Molecular Cell Research
JF - BBA - Molecular Cell Research
IS - 3
ER -