Spectroscopic quantitation of cytochrome P-450 in human lung microsomes

J Biochem Toxicol. 1990 Winter;5(4):269-72. doi: 10.1002/jbt.2570050410.


The cytochrome P-450 content of human lung microsomes was measured by difference spectroscopy of the carbon monoxide-complexed hemoprotein. These measurements were only possible after the microsome preparation had been subjected to centrifugation over a discontinuous sucrose gradient, to remove an opaque black contaminant. The specific concentration of total cytochrome P-450 in human lung microsomes is essentially identical to that of microsomes prepared under identical conditions from untreated baboon lungs, but is only 0.7% of the specific content found in lung microsomes from untreated rabbits. These measurements correspond well to the observed metabolic capacities of the various microsome samples.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 7-Alkoxycoumarin O-Dealkylase / metabolism
  • Animals
  • Aryl Hydrocarbon Hydroxylases / metabolism
  • Carbon Monoxide / metabolism
  • Cytochrome P-450 Enzyme System / analysis*
  • Humans
  • Lung / enzymology*
  • Microsomes / enzymology*
  • Papio
  • Rabbits
  • Species Specificity
  • Spectrophotometry


  • Carbon Monoxide
  • Cytochrome P-450 Enzyme System
  • 7-Alkoxycoumarin O-Dealkylase
  • Aryl Hydrocarbon Hydroxylases