Protein Information

Name cytochrome P 450 reductase
Synonyms CPR; CYPOR; Cytochrome P 450 reductase; Cytochrome P450 reductase; NADPH cytochrome P450 reductase; NADPH cytochrome P450 reductase; P450 (cytochrome) oxidoreductase; P450R…

Compound Information

Name diquat
CAS

Reference List

PubMed Abstract RScore(About this table)
10838165 Bayol-Denizot C, Daval JL, Netter P, Minn A: Xenobiotic-mediated production of superoxide by primary cultures of rat cerebral endothelial cells, astrocytes, and neurones. Biochim Biophys Acta. 2000 Jun 2;1497(1):115-26.

In order to characterise the risk of oxidative stress to both the central nervous system and the blood-brain barrier, we measured in the present work the release of superoxide in the culture medium of rat cerebrovascular endothelial cells during the metabolism of menadione, anthraquinone, diquat or nitrofurazone.
Superoxide formation by microsomes prepared from the cultured cells was decreased by immunoinhibition of NADPH-cytochrome P450 reductase or by its irreversible inhibition by diphenyliodonium chloride, suggesting the involvement of this flavoprotein in radical production.
1(0,0,0,1) Details
7575675 Blakeman DP, Ryan TP, Jolly RA, Petry TW: Diquat-dependent protein carbonyl formation. Biochem Pharmacol. 1995 Sep 28;50(7):929-35.

0(0,0,0,0) Details
9488113 Chat M, Bayol-Denizot C, Suleman G, Roux F, Minn A: Drug metabolizing enzyme activities and superoxide formation in primary and immortalized rat brain endothelial cells. Life Sci. 1998;62(2):151-63.

The superoxide production observed during NADPH-cytochrome P450 reductase-dependent monoelectronic reduction of four xenobiotics, menadione, anthraquinone, nitrofurazone and diquat, was also investigated in these cultured cells at confluence.
82(1,1,1,2) Details
2384057 Adam A, Smith LL, Cohen GM: An assessment of the role of redox cycling in mediating the toxicity of paraquat and nitrofurantoin. Environ Health Perspect. 1990 Apr;85:113-7.

This was reflected in kinetic studies using lung and liver microsomes, which showed that NADPH-cytochrome P-450 reductase had a lower affinity (Km) for paraquat and nitrofurantoin than for menadione and diquat, although values of Vmax were comparable for all the substrates except nitrofurantoin, which was lower.
81(1,1,1,1) Details
1654843 DeGray JA, Rao DN, Mason RP: Reduction of paraquat and related bipyridylium compounds to free radical metabolites by rat hepatocytes. Arch Biochem Biophys. 1991 Aug 15;289(1):145-52.

The reduction of paraquat is generally attributed to NADPH-cytochrome P-450 reductase, and presumably diquat is also reduced by this flavoprotein.
31(0,1,1,1) Details
3421716 Tsokos-Kuhn JO: Lethal injury by diquat redox cycling in an isolated hepatocyte model. Arch Biochem Biophys. 1988 Sep;265(2):415-24.

Specific activities of NADPH-cytochrome P-450 reductase in isolated Fischer and Sprague-Dawley rat liver microsomes utilizing 1 mM diquat as acceptor were 0.085 +/- 0.017 and 0.076 +/- 0.028 mumol/mg.min (mean +/- SEM, N = 5), respectively, indicating the capacity for very active redox cycling of diquat by this route in both strains.
6(0,0,1,1) Details