title: Persistent enhancement of potassium-induced responses of the rat vas deferens by desipramine.
abstract: The effect of desipramine on the cumulative dose-response curves of noradrenaline and potassium (K+) was examined on the isolated rat vas deferens. An exposure of 10 min to 10(-7) M desipramine caused a leftward shift and an increase in the maximum response of cumulative dose-response curves of noradrenaline. Desipramine (10(-7) M), in contact with the tissue for 10 min, enhanced responses to cumulative additions of K+ without causing a consistent change in threshold concentrations. Wash-out of desipramine resulted in a rapid loss of enhanced maximum response to noradrenaline while the maximum response to K+ did not show any decrease for up to 120 min after wash-out of drug. One possible explanation for the persistent enhancement of K+-induced responses may be that desipramine causes postjuntional changes which selectively influence contractile responses of this tissue to K+.
mesh_terms: D000818:Animals; D003891:Desipramine / Q000494:pharmacology*; D004357:Drug Synergism; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D014649:Vas Deferens / Q000187:drug effects
chemical_list: D011188:Potassium; D003891:Desipramine; D009638:Norepinephrine