Abstract

The cytochrome P-450 3A family is involved in the metabolism of several drugs, including nifedipine, cyclosporine, quinidine and erythromycin. The purpose of this study was to develop a reliable method to obtain a relative quantification of cytochrome P-450 3A apoproteins in rat liver specimens by immunocytochemistry and to correlate such quantification to erythromycin N-demethylase activity, a biochemical pathway sustained by that enzymatic system. Thirty-six male Wistar rats were treated with an injection of either saline or dexamethasone phosphate (10, 30 or 50 mg/kg), a potent inducer of cytochrome P-450 3A. Specimens taken from the same lobe were processed for immunocytochemistry and determination of erythromycin N-demethylase activity. Paraffin sections were treated with a polyclonal antiserum directed against cytochrome P-450 3A. The density of cytochrome P-450 3A immunostaining measured by an automatic image analyzer increased with the dose of dexamethasone pretreatment, and with the erythromycin N-demethylase activity, both parameters being closely correlated. Our data indicate that in rats, when cytochrome P-450 3A is concerned, there is a close correlation between the results of immunoquantitation and biochemical activity. This suggests that such a method of investigation might be used on small paraffin-embedded liver specimens obtained by needle biopsy.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.