Effect of isoflurane on release and uptake of gamma-aminobutyric acid from rat cortical synaptosomes.
We have studied the effect of isoflurane on potassium-evoked release and high-affinity uptake of gamma-aminobutyric acid (GABA) in rat cortical synaptosomes. Isoflurane 1.5% and 3% increased calcium-dependent release by 38% and 36% of control values, respectively (P < 0.05). Calcium-independent release was reduced correspondingly by 24% and 26% (P < 0.05). High-affinity uptake of GABA was not affected by isoflurane. The findings of increased synaptic GABA release combined with unaltered uptake suggest that isoflurane increases GABA in the synaptic cleft and thus may enhance inhibition.
Institute for Surgical Research, Rikshospitalet, Oslo, Norway.
M
M
Larsen
T S
TS
Haugstad
J
J
Berg-Johnsen
I A
IA
Langmoen
D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007530:Isoflurane / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013574:Synaptosomes / Q000187:drug effects* / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018685:Anesthetics, Inhalation; D005680:gamma-Aminobutyric Acid; D007530:Isoflurane; D011188:Potassium; D002118:Calcium