Evidence for two distinct chloride uniport pathways in brown adipose tissue mitochondria.
Chloride permeability of the inner membrane of brown adipose tissue mitochondria was analyzed by monitoring mitochondrial swelling in KCl salts in the presence of K+ ionophores. The results indicate that the high anion conductance observed in these mitochondria is due to the presence of two separate pathways: 1) a Cl-conducting pathway that is inhibited by guanosine 5'-diphosphate (GDP) but neither by N,N'-dicyclohexylcarbodiimide (DCCD) nor by amphiphilic amines and that is found uniquely in brown adipose tissue mitochondria and 2) an inner membrane anion uniport channel that is inhibited both by DCCD and by amphiphilic amines but not by GDP and that is opened either by depletion of matrix Mg2+ or by alkalinization of the matrix.
Jezek
P
P
Department of Pharmacology, Medical College of Ohio, Toledo 43699.
Beavis
A D
AD
Diresta
D J
DJ
Cousino
R N
RN
Garlid
K D
KD
D002001:Adipose Tissue, Brown / Q000378:metabolism*; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D000001:Calcimycin / Q000494:pharmacology; D018118:Chloride Channels; D002712:Chlorides / Q000378:metabolism*; D002716:Chlormequat / Q000494:pharmacology; D006224:Cricetinae; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D004492:Edetic Acid / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000494:pharmacology; D007425:Intracellular Membranes / Q000187:drug effects / Q000378:metabolism; D007473:Ion Channels / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins / Q000378:metabolism*; D008647:Mesocricetus; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism*; D008954:Models, Biological; D011433:Propranolol / Q000494:pharmacology; D014220:Trialkyltin Compounds / Q000494:pharmacology
D018118:Chloride Channels; D002712:Chlorides; D007473:Ion Channels; D008565:Membrane Proteins; D014220:Trialkyltin Compounds; D006153:Guanosine Diphosphate; D000001:Calcimycin; C011559:tributyltin; D004024:Dicyclohexylcarbodiimide; D002716:Chlormequat; D004492:Edetic Acid; D011433:Propranolol