Plants - Drugs Mind - Spirit Freedom - Law Arts - Culture Library  
Erowid References Database
Langer SZ, Moret C. 
“Citalopram Antagonizes the Stimulation by Lysergic Acid Diethylamide of Presynaptic Inhibitory Serotonin Autoreceptors in the Rat Hypothalamus”. 
J. Pharm. Exper. Ther.. 1982;222(1).
Slices of rat hypothalamus prelabeled with [3H]5-hydroxytryptamine ([3H]5-HT) were superfused and the release of the labeled transmitter was elicited either by electrical stimulation or by fenfluramine. Whereas the electrically stimulated release of [3H]5-HT was completely abolished by removing calcium from the superfusion medium, the fenfluramine-induced release of [3H]5-HT was calcium-independent. Methiothepin increased, in a concentration-dependent manner, the [3H]5-HT release induced by electrical stimulation but had no effect on that elicited by fentiuramine. The 3H-transmitter release elicited by electrical stimulation was inhibited by lysergic acid diethylamide (LSD) in a concentration-dependent manner, but the release induced by fenfluramine was not modified by LSD. The reduction by LSD of [3H]5-HT overflow elicited by electrical stimulation was antagonized by methiothepin, but unaffected by phentolamine or by suipiride. Low concentrations (10- 1000 nM) of citalopram, a 5-HT uptake inhibitor, antagonized the inhibition by LSD of electrically evoked release of [3H]-5-HT. These concentrations of citalopram did not modify by themselves th overflow of [3H]-5-HT elicited by electrical simulation. It is concluded that the modulation of [3H]-5-HT release by presynaptic serotonin autorectpors is not operational when the neurotransmitter is released through a calcium-independent mechanism. The potent presynaptic inhibtion by LSD of serotonergic meurotransmission may contributed to the central actions of this drug. The interaction between citalopram and LSD at the level of [3H]-5-HT release does not seem to involve a competitive interaction at the same receptor site. The possibility that neuronal uptake of 5-HT and the presynaptic 5-HT autoreceptor may be linked in a functional manner cannot be excluded.
Comments and Responses to this Article
Submit Comment
[ Cite HTML ]