Tetrahydronorharmane modulates the depolarisation-induced efflux of 5-hydroxytryptamine and dopamine and is released by high potassium concentration from rat brain slices.
Tetrahydronorharmane (THN), a compound which occurs in man and in rats is supposed to act as a modulator of 5-hydroxytryptaminergic neurones. It is reported here that THN stimulated the potassium-induced release of the neurotransmitter from brain slices. This suggests enhancement of the efflux as a mechanism for the 5-hydroxytryptamine-like action of THN in pharmacological experiments. Furthermore, THN decreased the potassium-evoked efflux of (3H)-dopamine. This is consistent with the inhibition of dopaminergic neurones by THN as seen previously in various in vivo experiments. Finally it is demonstrated that a high concentration of potassium evokes the efflux of (14C)-THN from brain slices. This finding suggests that THN is taken up into neurones and exerts its modulating action on serotonergic neurones either inside or outside the cell.
D000818:Animals; D001923:Brain Chemistry / Q000187:drug effects*; D002118:Calcium; D002243:Carbolines / Q000494:pharmacology*; D003342:Corpus Striatum / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D011188:Potassium / Q000378:metabolism; D051381:Rats; D012701:Serotonin / Q000378:metabolism / Q000494:pharmacology*
D002243:Carbolines; D007211:Indoles; D012701:Serotonin; D011188:Potassium; D002118:Calcium; D004298:Dopamine