Effects of p-chloroamphetamine on release of [3H]gamma-aminobutyric acid from slices of rat caudate-putamen.
The effect of endogenous serotonin on the release of [3H]gamma-aminobutyric acid ([3H]GABA) from slices of rat caudate-putamen was studied. p-Chloroamphetamine was used to release endogenous serotonin. p-Chloroamphetamine (100 nM) enhanced the release of [3H]GABA induced by 20 mM K+, while 1000 nM p-chloroamphetamine decreased it. The 5-HT3 receptor antagonists ICS 205-930 (50 nM) and MDL 72222 (100 nM) prevented this facilitation caused by 100 nM p-chloroamphetamine. ICS 205-903 (50 nM), when used alone, reduced the release of [3H]GABA caused by 23 mM K+. This finding confirmed the hypothesis that endogenous serotonin can enhance the release of [3H]GABA via 5-HT3 receptors. In contrast, an effect of 5-HT1 and 5-HT2 receptors could not be clearly established. It is likely that the release of endogenous GABA from striatonigral GABA neurons may also be affected by serotonin via 5-HT3 receptors.
Meyer
D K
DK
Department of Pharmacology, University of Freiburg, F.R.G.
Holland
A
A
Lais
A
A
Szabo
B
B
D000818:Animals; D002421:Caudate Nucleus / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D007211:Indoles / Q000494:pharmacology; D008297:Male; D011699:Putamen / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology; D012702:Serotonin Antagonists / Q000494:pharmacology; D014326:Tropanes / Q000494:pharmacology; D000077526:Tropisetron; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*; D010133:p-Chloroamphetamine / Q000494:pharmacology*
D007211:Indoles; D011942:Receptors, Adrenergic, alpha; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014326:Tropanes; D005680:gamma-Aminobutyric Acid; D010133:p-Chloroamphetamine; D000077526:Tropisetron; C042253:bemesetron