Effects of divalent cations on acetylcholine release from digitonin-permeabilized rat cortical synaptosomes.
A preparation of rat brain synaptosomes, partially permeabilized by the cholesterol-specific detergent digitonin, was developed to study the effects of the heavy metals Pb+2 and Cd+2 and of other divalent cations on acetylcholine release from nerve terminals. Consistent with the cation specificities of the transmitter release process in intact nerve terminals, 100 microM free Ba+2, Sr+2 and Ca+2 each induced a release of acetylcholine (ACh) while Ni+2, Co+2 and Mn+2 did not. 100 microM Pb+2 and Cd+2 also induced a release of ACh from the permeabilized synaptosomes. This suggests that, similar to Ba+2 and Sr+2, both Pb+2 and Cd+2 may induce transmitter release through a direct action on the transmitter release apparatus.
Toth
G P
GP
Department of Physiology and Biophysics, University of Cincinnati, College of Medicine, Ohio 45267-0576.
Cooper
G P
GP
Suszkiw
J B
JB
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002413:Cations, Divalent / Q000494:pharmacology*; D002540:Cerebral Cortex / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D004072:Digitonin / Q000494:pharmacology*; D008297:Male; D008670:Metals / Q000494:pharmacology; D010539:Permeability; D051381:Rats; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism
D002413:Cations, Divalent; D008670:Metals; D002795:Choline O-Acetyltransferase; D004072:Digitonin; D000109:Acetylcholine