Potassium markedly potentiates the effect of veratridine on dopamine release from rat superfused striatal ribbons.
The effects of veratridine-induced depolarization on [3H]dopamine ([3H]DA) release in the presence of a physiological (5 mM) or a depolarizing (25 mM) concentration of K+ were studied in-vitro in rat superfused striatal ribbons. A combination of the two depolarizing agents induced a marked potentiation in the overflow of [3H]DA, giving an overall 3- to 5-fold increase in veratridine activity. This potentiation was completely antagonized by tetrodotoxin (100 nM). These studies indicated that K(+)-induced depolarization can increase the potency of veratridine in releasing dopamine from terminals.
Olivier
V
V
Rhône-Poulenc Rorer S.A., Centre de Recherche de Vitry-Alfortville, Département Biologie, Vitry-sur-Seine, France.
Miquet
J M
JM
Aubeneau
M
M
Blanchard
J C
JC
Doble
A
A
Boireau
A
A
D000818:Animals; D002118:Calcium / Q000502:physiology; D003342:Corpus Striatum / Q000187:drug effects / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004357:Drug Synergism; D066298:In Vitro Techniques; D008297:Male; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013779:Tetrodotoxin / Q000494:pharmacology; D014701:Veratridine / Q000494:pharmacology*
D013779:Tetrodotoxin; D016291:Dizocilpine Maleate; D014701:Veratridine; D011188:Potassium; D002118:Calcium; D004298:Dopamine