Chloride permeability of rat brain membrane vesicles correlates with thiamine triphosphate content.
Incubation of rat brain homogenates with thiamine or thiamine diphosphate (TDP) leads to a synthesis of thiamine triphosphate (TTP). In membrane vesicles subsequently prepared from the homogenates, increased TTP content correlates with increased 36Cl- uptake. A hyperbolic relationship was obtained with a K0.5 of 0.27 nmol TTP/mg protein. In crude mitochondrial fractions from the brains of animals previously treated with thiamine or sulbutiamine, a positive correlation between 36Cl- uptake and TTP content was found. These results, together with other results previously obtained with the patch-clamp technique, suggest that TTP is an activator of chloride channels having a large unit conductance.
Laboratory of Neurochemistry, University of Liège, Belgium.
L
L
Bettendorff
B
B
Hennuy
A
A
De Clerck
P
P
Wins
D000818:Animals; D001923:Brain Chemistry / Q000502:physiology*; D002463:Cell Membrane Permeability / Q000502:physiology; D018118:Chloride Channels / Q000378:metabolism*; D002713:Chlorine; D002851:Chromatography, High Pressure Liquid; D066298:In Vitro Techniques; D010766:Phosphorylation; D011619:Psychotropic Drugs / Q000494:pharmacology; D011868:Radioisotopes; D051381:Rats; D013831:Thiamine / Q000031:analogs & derivatives / Q000494:pharmacology; D013838:Thiamine Triphosphate / Q000378:metabolism*
D018118:Chloride Channels; D011619:Psychotropic Drugs; D011868:Radioisotopes; D013838:Thiamine Triphosphate; C031331:sulbutiamine; D002713:Chlorine; D013831:Thiamine