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Extracellular ATP-induced production of hydrogen peroxide in porcine thyroid cells

1990; Bioscientifica; Volume: 126; Issue: 2 Linguagem: Inglês

10.1677/joe.0.1260283

1479-6805

Yoichi Nakamura, Sachiya Ohtaki,

Mitochondrial Function and Pathology

ABSTRACT Hydrogen peroxide (H 2 O 2 ) is an essential substrate for the peroxidase reaction in thyroid hormone biosynthesis. We demonstrated the production of H 2 O 2 from porcine thyroid cells stimulated with extracellular ATP, using a scopoletin–horseradish peroxidase (HRP) system. Incubation of isolated cells for 1 day in the presence of 10% (v/v) newborn calf serum was necessary for the detection of induction by ATP of H 2 O 2 production. The rate of H 2 O 2 production induced by the addition of ATP increased in a dose-dependent manner, and the concentration of ATP required for half-maximum stimulation was about 10 μmol/l. ADP and GTP were also effective, but only at higher concentrations than ATP. In the absence of extracellular Ca 2+ , the production rate was very low. Production of H 2 O 2 from thyroid cells was also measured by a method which discriminated between H 2 O 2 and superoxide anion (O 2 − ); in this, diacetyl-deuteroheme-substituted HRP was employed as the trapping agent for both O 2 metabolites. The thyroid cells produced H 2 O 2 , but not O 2 − , when the cells were stimulated by extracellular ATP. Journal of Endocrinology (1990) 126, 283–287