title: Effect of some cardiac and respiratory drugs on succinate-cytochrome c reductase.
abstract: Succinate-cytochrome c reductase was inhibited in vitro and in vivo by phenobarbitone, aminophylline and neostigmine using both 2,6-dichlorophenolindophenol (DCIP) and cytochrome c (cyt c) as substrates. The enzyme was also activated by gallamine towards both substrates. In vitro, phenobarbitone and aminophylline inhibited the enzyme with respect to the reduction of DCIP and cyt c in a non-competitive manner with Ki values of 1.5 x 10(-5) and 5.7 x 10(-5)M, respectively. Moreover, neostigmine competitively inhibited the enzyme towards both substrates with Ki values of 1.36 x 10(-5) and 1.50 x 10(-5)M, respectively.
authors.affiliation: Department of Chemistry, College of Science, Qatar University, P.O. Box 2713, Doha, Qatar. m_balbaa@hotmail.com
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Balbaa
authors.forename: Jehan
authors.initials: J
authors.lastname: Al-Meer
authors.forename: Amina
authors.initials: A
authors.lastname: Al-Khal
mesh_terms: D000818:Animals; D002317:Cardiovascular Agents / Q000494:pharmacology*; D005703:Gallamine Triethiodide / Q000494:pharmacology; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D051379:Mice; D015394:Molecular Structure; D009388:Neostigmine / Q000494:pharmacology; D010634:Phenobarbital / Q000494:pharmacology; D019141:Respiratory System Agents / Q000494:pharmacology*; D013384:Succinate Cytochrome c Oxidoreductase / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D013806:Theophylline / Q000494:pharmacology
chemical_list: D002317:Cardiovascular Agents; D019141:Respiratory System Agents; D009388:Neostigmine; D013806:Theophylline; D013384:Succinate Cytochrome c Oxidoreductase; D005703:Gallamine Triethiodide; D010634:Phenobarbital