Influence of induction and flavones on lung microsomal oxygen metabolism

Conference · Thu May 01 00:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5176951

Gregory, E M; Barlow, R; Ebel, R E

NADPH oxidase activity, H/sub 2/O/sub 2/ production and O/sub 2/ production were studied using microsomes isolated from lungs of control rats and rats treated with phenobarbital (PB), 3-methylcholanthrene (3-MC), 5,6-benzoflavone (..beta..-NF), or chlordecone (CD). 3-MC, ..beta..-NF or Cd treatment resulted in induction of lung P-450 and P-450 reductase. NADPH oxidase activity was slightly higher in 3-MC or ..beta..-NF lung microsomes than in control, PB or CD microsomes. 5 mM metyrapone inhibited oxidase activity of these microsomes by 20-50% depending upon their source. The rates of H/sub 2/O/sub 2/ and O/sub 2/ production did not appear to vary significantly as a function of induction and metyrapone had only a marginal effect on these rates. The rates of H/sub 2/O/sub 2/ and O/sub 2/ production at 37/sup 0/ were 1.8 +/- 0.2 and 1.8 +/- 0.3 nmol/min/mg, respectively. 50 ..mu..M ..beta..-NF stimulated H/sub 2/O/sub 2/ production by about 2-fold regardless of microsomal source while the stimulation of O/sub 2/ production was marginal. In each case, the effect of ..beta..-NF was greater than a comparable amount of 7,8-benzoflavone (..cap alpha..-NF). NADPH oxidase activity was dramatically stimulated by ..beta..-NF. For example, at 37/sup 0/ 100 ..mu..M ..beta..-NF increased the oxidase activity of control lung microsomes by about 9-fold from 3.4 to 31.6 nmol/min/mg. Lung microsomes from induced rats were comparably stimulated by ..beta..-NF. This stimulation was concentration dependent although not hyperbolic. Metyrapone did not inhibit the ..beta..-NF stimulated NADPH oxidase activity.

• Research Organization: Virginia Tech, Blacksburg
• OSTI ID: 5176951
• Report Number(s): CONF-8606151-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
59 BASIC BIOLOGICAL SCIENCES
3-METHYLCHOLANTHRENE
BIOLOGICAL EFFECTS
FLAVONES
OXIDOREDUCTASES
ENZYME ACTIVITY
OXYGEN
METABOLISM
PHENOBARBITAL
HYDROGEN PEROXIDE
LUNGS
MICROSOMES
NADP
ANESTHETICS
ANTICONVULSANTS
AROMATICS
AZINES
BARBITURATES
BODY
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
COENZYMES
DRUGS
ELEMENTS
ENZYMES
FLAVENOIDS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROGEN COMPOUNDS
HYPNOTICS AND SEDATIVES
NONMETALS
NUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANOIDS
ORGANS
OXYGEN COMPOUNDS
PEROXIDES
POLYCYCLIC AROMATIC HYDROCARBONS
PYRIMIDINES
RESPIRATORY SYSTEM
560301* - Chemicals Metabolism & Toxicology- Cells- (-1987)
550500 - Metabolism