Participation of NADPH-cytochrome C reductase in thyroid hormone biosynthesis.
Purified rat liver NADPH-cytochrome c reductase supports iodination of tyrosine in a system including NADPH, cytochrome c and thyroid perioxidase. Catalase inhibits the iodination of tyrosine, while superoxide dismutase has no effect. Antibody developed in the rabbit against purified rat liver NADPH-cytochrome c reductase inhibits both reduction of cytochrome c and tyrosine iodination supported by the enzyme. The antibody forms a single precipitation line with thyroid extract, and inhibits NADPH cytochrome c reductase activity of the thyroid. The antibody partially inhibits iodination in a thyroid mitochondrial-microsomal fraction, but does not inhibit NADH-dependent iodination. The immunochemical studies indicate the participation of NADPH-cytochrome c reductase in thyroidal H2O generation, and the independent existence of NADPH-dependent and NADH-dependent H2O2 generation mechanisms in the thyroid.
D000818:Animals; D000906:Antibodies; D002374:Catalase / Q000494:pharmacology; D002417:Cattle; D003579:Cytochrome Reductases / Q000276:immunology / Q000378:metabolism*; D003574:Cytochrome c Group; D005779:Immunodiffusion; D066298:In Vitro Techniques; D007454:Iodides / Q000378:metabolism; D008861:Microsomes / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D009249:NADP; D010544:Peroxidases / Q000378:metabolism; D011817:Rabbits / Q000276:immunology; D051381:Rats; D013482:Superoxide Dismutase / Q000494:pharmacology; D013961:Thyroid Gland / Q000648:ultrastructure; D013963:Thyroid Hormones / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
D000906:Antibodies; D003574:Cytochrome c Group; D007454:Iodides; D013963:Thyroid Hormones; D014443:Tyrosine; D009249:NADP; D010544:Peroxidases; D002374:Catalase; D013482:Superoxide Dismutase; D003579:Cytochrome Reductases