Rabbit nasal cytochrome P-450 NMa has high activity as a nicotine oxidase

Biochem Biophys Res Commun. 1990 Jan 30;166(2):945-52. doi: 10.1016/0006-291x(90)90902-y.


Rabbit nasal olfactory and respiratory microsomes demonstrate high activity toward [3H]-(S)-nicotine, with specific activities of 22.2 and 6.5 nmol/min/mg protein, respectively. The major metabolite produced is (S)-nicotine delta 1'; 5'-iminium ion, with lesser amounts of nornicotine and the N'-oxide. Reconstitution of the rabbit nasal microsomal system with cytochromes P-450 NMa and NMb indicated that only P-450 NMa has significant activity toward nicotine, and the metabolite profile and turnover are similar to that observed with nasal microsomes. The low Km (35 microMs) and high Vmax (28 min-1) suggest that a significant portion of inhaled nicotine is metabolized by nasal tissues in the rabbit.

Publication types

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

MeSH terms

  • Animals
  • Cytochrome P-450 Enzyme System / metabolism*
  • Kinetics
  • Lung / enzymology
  • Microsomes / enzymology
  • Nasal Mucosa / enzymology*
  • Nicotine / metabolism*
  • Oxidoreductases / metabolism*
  • Rabbits
  • Substrate Specificity


  • Nicotine
  • Cytochrome P-450 Enzyme System
  • Oxidoreductases
  • nicotine oxidase