Further evidence for the prevention by guanethidine of noradrenaline efflux from rabbit ventricular slices induced by a low external sodium concentration.
When guanethidine was applied to rabbit ventricular slices at 37 degrees C for an initial 30 min incubation period, doses of 4 X 10(-5) and 8 X 10(-5) M irreversibly inhibited increases in efflux of noradrenaline induced by the subsequent reduction of external sodium concentrations to 18 mM. This inhibition was prevented if the temperature was reduced to 0 degrees C during the drug application period. Guanethidine transported into adrenergic nerve endings appears to increase permeability to Na+, thereby leading to the reduction in efflux.
D000818:Animals; D006145:Guanethidine / Q000494:pharmacology*; D066298:In Vitro Techniques; D009206:Myocardium / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D011817:Rabbits; D012964:Sodium / Q000502:physiology*; D013696:Temperature; D013997:Time Factors
D012964:Sodium; D009638:Norepinephrine; D006145:Guanethidine