Indications to an NADPH oxidase as a possible pO2 sensor in the rat carotid body.
The rat carotid body superfused with low pO2 exhibited an optical absorbance spectrum which resembles the reduced spectrum of the NADPH oxidase in neutrophils. Diphenylene iodonium (DPI) as a specific inhibitor of the oxidase attenuated the reduced absorbance spectrum in the carotid body. Also absorbance bleaching by low doses of cyanide (50 and 100 microM) was inhibited by DPI, whereas higher doses of cyanide (300 microM) caused an absorbance spectrum typical for reduced cytochromes. It is concluded that an NADPH oxidase acts as a pO2 sensor in the carotid body with low affinity for oxygen and high affinity for cyanide.
Acker
H
H
Max-Planck-Institut für Systemphysiologie, Dortmund 1, FRG.
Dufau
E
E
Huber
J
J
Sylvester
D
D
D000818:Animals; D002344:Carotid Body / Q000201:enzymology* / Q000378:metabolism; D003573:Cytochrome b Group / Q000378:metabolism; D000860:Hypoxia / Q000378:metabolism; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D019255:NADPH Oxidases; D009861:Onium Compounds / Q000494:pharmacology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000494:pharmacology*; D010477:Perfusion; D045332:Photosystem II Protein Complex; D011190:Potassium Cyanide / Q000494:pharmacology; D051381:Rats; D013053:Spectrophotometry / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods
D003573:Cytochrome b Group; D009861:Onium Compounds; D045332:Photosystem II Protein Complex; C007517:diphenyleneiodonium; C019313:cytochrome b559; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; D011190:Potassium Cyanide; D010100:Oxygen