title: Presence of an NAD(P)H dehydrogenase and A b-type cytochrome different from the respiratory chain in submitochondrial particles from human placenta.
abstract: Placental submitochondrial particles can synthesize progesterone. Both, progesterone synthesis and oxygen consumption were stimulated in the presence of succinate, NADH, or NADPH. NADPH reduced the cytochromes of the respiratory chain in a similar way as NADH. NADPH oxidation was not achieved by NADH-DH from the respiratory chain, and the presence of an NAD(P)H-DH is suggested. Submitochondrial particles contain at least two b-type cytochromes, one inhibited by antimycin when the electron donor is succinate, whereas the other is less sensitive to antimycin in the presence of pyridine nucleotides. The results suggest a connection between the respiratory chain and cytochrome P450, through an NAD(P)H-DH and a b-type cytochrome, both different from the respiratory chain.
authors.affiliation: Departmento de Bioquimica, Facultad de Medicina, Universidad Nacional Autonoma de Mexico.
authors.forename: M T
authors.initials: MT
authors.lastname: Espinosa-Garcia
authors.forename: F
authors.initials: F
authors.lastname: Martinez
mesh_terms: D000968:Antimycin A / Q000031:analogs & derivatives / Q000494:pharmacology; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D003573:Cytochrome b Group / Q000737:chemistry / Q000378:metabolism*; D003574:Cytochrome c Group / Q000378:metabolism; D004579:Electron Transport; D005260:Female; D006801:Humans; D009243:NAD / Q000378:metabolism; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry / Q000378:metabolism; D009245:NADH Dehydrogenase / Q000737:chemistry / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D009252:NADPH Dehydrogenase / Q000737:chemistry / Q000378:metabolism*; D010101:Oxygen Consumption / Q000187:drug effects; D010920:Placenta / Q000201:enzymology / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis; D012402:Rotenone / Q000494:pharmacology; D013367:Submitochondrial Particles / Q000201:enzymology / Q000378:metabolism*; D013386:Succinates / Q000378:metabolism; D019802:Succinic Acid
chemical_list: D003573:Cytochrome b Group; D003574:Cytochrome c Group; D013386:Succinates; D012402:Rotenone; D009243:NAD; C032456:antimycin; D011374:Progesterone; D009249:NADP; D000968:Antimycin A; D003577:Cytochrome P-450 Enzyme System; D019802:Succinic Acid; D016660:NAD(P)H Dehydrogenase (Quinone); D009252:NADPH Dehydrogenase; D009245:NADH Dehydrogenase