The role of heme metabolism during the induction of hepatic and renal cytochrome P -450 levels and drug-metabolizing enzymes in rats by a Prudhoe Bay crude oil

• Published in: Canadian Journal of Physiology and Pharmacology
• Main Authors: Khan, S., Rahimtula, A. D.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1987
• Subjects: Physiology (medical); Pharmacology; General Medicine; Physiology; Prudhoe Bay
• Online Access: http://dx.doi.org/10.1139/y87-014; http://www.nrcresearchpress.com/doi/pdf/10.1139/y87-014

Administration of Prudhoe Bay crude oil (PBCO) to rats resulted in a dose-related (i) increase in liver weight; (ii) rapid and marked increase in the activity of hepatic δ-aminolevulinate synthetase, the initial and rate-limiting enzyme in the heme biosynthetic pathway; (iii) rapid decline in the activity of hepatic heme oxygenase, the rate-limiting enzyme of heme catabolism; and (iv) more gradual increase in the levels of hepatic cytochrome P-450 and some mixed-function oxidase activities such as benzo[a]pyrene hydroxylase and 7-ethoxyresorufin-O-deethylase. PBCO treatment also increased renal cytochrome P-450 levels and mixed-function oxidase activities; however, δ-aminolevulinate synthetase and heme oxygenase activities were unchanged. This suggests that different regulatory mechanism(s) may be involved in renal heme metabolism and induction of monoxygenase system.