Abstract
Human kidney cortex microsomes were found to contain both cytochromes P-450 and b5; the concentration of cytochrome b5 was 4 to 5 times greater than the concentration of cytochrome P-450, assuming the same extinction coefficients obtained with rat liver, in contrast to that present in rat kidney cortex or human liver microsomes. Addition of laurate to a microsomal suspension from human kidney produced a type I spectral change, the magnitude of which was similar to that found with rat kidney microsomes; however, ω- and (ω-1)-hydroxylation of laurate was about one-half the rate observed in rat kidney cortex microsomes based on the content of cytochrome P-450. Furthermore, aminopyrine, which caused a modified type II (reverse type I) spectral change, was metabolized to the same extent as laurate, which suggests a lower substrate specificity by human kidney cortex cytochrome P-450 than by rat kidney P-450.
Footnotes
- Received October 30, 1972.
- Accepted January 3, 1973.
- © 1973 by The Williams & Wilkins Co.