Interacting effects of dibutylchloromethyltin chloride, 2,3-dimercaptopropanol, and other reagents on mitochondrial respiration and K+ flux.
The oxidative phosphorylation inhibitor DBCT (dibutylchloromethyltin chloride) inhibits state 3 respiration at a concentration less than that which stimulates K+ flux into respiring rat liver mitochondria. Inhibition of ADP-stimulated respiration by DBCT can be reversed or blocked by the dithiol 2,3-dimercaptopropanol. The data are consistent with previous suggestions that DBCT may interact with the ATP synthase via reaction with a dithiol group. The stimulation of K+ influx by DBCT is partially reversed by concentrations of 2-mercaptoethanol which fail to affect the inhibition of state 3 respiration by DBCT. The combination of DBCT plus 2,3-dimercaptopropanol inhibits mitochondrial K+ influx. The inhibitory effect of dicyclohexylcarbodiimide on K+ influx is not expressed in the presence of DBCT. Atractyloside has little effect on K+ influx in the presence or absence of DBCT. The combination of DBCT plus uncoupler induces a net loss of endogenous K+. Consideration is given to the alternative hypotheses that the acceleration of K+ influx by DBCT may involve either a direct link to the energy transduction apparatus, or may occur via separate activation of a passive transport mechanism.
Diwan
J J
JJ
Biology Department, Rensselaer Polytechnic Institute, Troy, New York 12181, USA.
DeLucia
A
A
Rose
P E
PE
D000818:Animals; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004112:Dimercaprol / Q000494:pharmacology*; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D017136:Ion Transport / Q000187:drug effects; D008623:Mercaptoethanol / Q000494:pharmacology; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D011188:Potassium / Q000378:metabolism*; D051381:Rats; D014220:Trialkyltin Compounds / Q000494:pharmacology*
D007202:Indicators and Reagents; D014220:Trialkyltin Compounds; D004112:Dimercaprol; D004024:Dicyclohexylcarbodiimide; D008623:Mercaptoethanol; C015129:dibutylchloro(chloromethyl)tin; D011188:Potassium