The acceleration of the extraneuronal efflux of 3H-(+/-)-isoprenaline induced by high extracellular potassium.
After loading of the extraneuronal tissues of the perfused rat heart with 3H-isoprenaline the elevation of extracellular K+ concentration (from 2.7 to 15 mmol/l) in the perfusion solution about doubled the rate constant for efflux of the 3H-amine. As this increase was not seen in the presence of 100 mumol/l 3-O-methyl-isoprenaline (OMI, a potent inhibitor of the uptake2-carrier), it is concluded that the change in the concentration of K+ modulates OMI-sensitive outward transport of 3H-isoprenaline by uptake2, not the diffusional efflux of the amine.
Grohmann
M
M
Institut für Pharmakologie und Toxikologie, Universität Würzburg, Federal Republic of Germany.
D000818:Animals; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012110:Reserpine / Q000494:pharmacology
D012110:Reserpine; D007545:Isoproterenol; D011188:Potassium