title: The effect of carbonyl cyanide m-chlorophenylhydrazone on steroid transport in membrane vesicles of Pseudomonas testosteroni.
abstract: The uncoupler carbonyl cyanide chlorophenylhydrazone (CCCP) was an effective inhibitor of steroid transport in membrane vesicles of Pseudomonas testosteroni between 10 microM and 1 microM CCCP. At these concentrations the inhibition of steroid transport was not due to an inhibition of the 3 beta and 17 beta-hydroxysteroid dehydrogenase enzyme. CCCP also affected testosterone-dependent oxygen consumption at concentrations up to 100 microM and inhibited respiration at 0.5 and 1 microM. The effect of CCCP on testosterone-dependent oxygen consumption indicated that CCCP was acting as an uncoupler. The concurrent inhibition of testosterone transport and stimulation of testosterone-dependent oxygen consumption at 10-100 microM CCCP supported the conclusion that transport and metabolism were tightly coupled processes. When membrane vesicles were pre-incubated with CCCP for 15 min, CCCP did inhibit transport and the 3 beta and 17 beta-hydroxysteroid dehydrogenase activity. However, both transport and enzyme inhibition could be prevented by the addition of NAD+ to the incubation mixture. This indicated that CCCP exhibits the properties of a sulfhydryl reagent under pre-incubated conditions.
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors; D015096:3-Hydroxysteroid Dehydrogenases / Q000037:antagonists & inhibitors; D001693:Biological Transport, Active / Q000187:drug effects; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology*; D002462:Cell Membrane / Q000378:metabolism; D009243:NAD / Q000494:pharmacology; D009570:Nitriles / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects; D011549:Pseudomonas / Q000378:metabolism*; D013739:Testosterone / Q000378:metabolism* / Q000494:pharmacology
chemical_list: D009570:Nitriles; D009243:NAD; D013739:Testosterone; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D015067:17-Hydroxysteroid Dehydrogenases; D015096:3-Hydroxysteroid Dehydrogenases; C032690:3-alpha-(17-beta)-hydroxysteroid dehydrogenase (NAD(+))