Effects of 250 mg% ethanol on monoamine and amino acid release from rat striatal slices.
A single IP injection of 2.5 g ethanol/kg body weight into the rat increased the striatal levels of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) one hour later to 133 and 141% of control values, respectively. Blood alcohol concentrations at this time were approximately 250 mg%. The increased striatal tissue levels of DOPAC and HVA found after IP administration did not appear to be due to a direct effect of ethanol on the efflux of these two metabolites or on the release of dopamine (DA) since in vitro studies with striatal slices demonstrated that 250 mg% ethanol had no effect on the endogenous release of DOPAC, HVA, or DA. However, ethanol did enhance the K+-stimulated, Ca2+-dependent release of glutamate and aspartate from striatal slices to 168 and 214% of control values, respectively. The release of glutamate and aspartate from slices of midbrain (minus colliculi) was also increased by 250 mg% ethanol. On the other hand, the release of GABA, NE and 5-HT did not appear to be significantly altered by 250 mg% ethanol. The in vitro findings have led to the hypothesis that the elevated DOPAC and HVA levels observed in the striatum following an acute IP injection of 2.5 g/kg of ethanol are due to increased release of DA produced by the excitatory actions of glutamate (and/or aspartate) on dopaminergic neurons.
Murphy
J M
JM
Cunningham
S D
SD
McBride
W J
WJ
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D002118:Calcium / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects*; D000431:Ethanol / Q000494:pharmacology*; D006719:Homovanillic Acid / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000596:Amino Acids; D001679:Biogenic Amines; D018377:Neurotransmitter Agents; D015102:3,4-Dihydroxyphenylacetic Acid; D000431:Ethanol; D011188:Potassium; D002118:Calcium; D006719:Homovanillic Acid