The influence of folic acid on the picrotoxin-sensitive site of the GABAa-receptor complex.
The site of action responsible for the convulsive effect of folic acid was investigated in vitro. Folic acid (ECmax 5 x 10(-4) M) enhances the binding of the cage convulsant [3H]t-butylbicycloorthobenzoate ([3H]TBOB) to rat brain membranes, namely to 130% of control in the absence of GABA and to over 300% of control in the presence of physiological concentrations of GABA. Analysis of the binding parameters reveals that folic acid increases the apparent number of [3H]TBOB binding sites.
Van Rijn
C M
CM
Dept. of Experimental Neurology, University of Nijmegen, The Netherlands.
Van der Velden
T J
TJ
Rodrigues de Miranda
J F
JF
Feenstra
M G
MG
Hommes
O R
OR
D000818:Animals; D001667:Binding, Competitive; D001643:Bridged Bicyclo Compounds / Q000378:metabolism; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003292:Convulsants / Q000378:metabolism*; D005492:Folic Acid / Q000378:metabolism*; D008297:Male; D010852:Picrotoxin / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects / Q000378:metabolism*
D001643:Bridged Bicyclo Compounds; D019086:Bridged Bicyclo Compounds, Heterocyclic; D003292:Convulsants; D005492:Folic Acid; D010852:Picrotoxin; D011963:Receptors, GABA-A; C046308:tert-butylbicyclo-2-benzoate