Stimulation of 3H-norepinephrine release by trifluoperazine from rat pineal glands.
Trifluoperazine (5-200 microM) stimulated the release of 3H-NE from isolated whole pineal glands in a dose dependent manner. Trifluoperazine-induced release was not dependent on extracellular Ca++, whereas 60 mM K+-evoked release was attenuated in the presence of EGTA and zero Ca++ Krebs. 60 mM K+ and 50 microM trifluoperazine produced an additive effect on 3H-NE release. Clonidine (5 microM) significantly reduced trifluoperazine-induced release by approximately 50% in the presence of Ca++, and in its absence, clonidine significantly attenuated the trifluoperazine response by 42%. Thus trifluoperazine may be acting upon the alpha 2 receptor or intracellular stores of Ca++. These intracellular interactions remain for further study.
D000818:Animals; D002118:Calcium / Q000378:metabolism; D003000:Clonidine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D007099:Imipramine / Q000494:pharmacology; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010870:Pineal Gland / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013268:Stimulation, Chemical; D014268:Trifluoperazine / Q000494:pharmacology*; D015016:Yohimbine / Q000494:pharmacology
D014268:Trifluoperazine; D015016:Yohimbine; D003000:Clonidine; D007099:Imipramine; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine