Wirkungsverstärkung von Adrenalin und Noradrenalin durch Azetylcholin am isolierten Irisdilatator des Kaninchens

Radial strips of the isolated iris of rabbits were suspended in streaming Tyrode's solution and their contractions were registered isometrically. The contractions produced by adrenaline or noradrenaline were increased after the administration of eserine or neostigmine. Acetylcholine in a concentration 5.10−7−5.10−6 M enhanced the effect of adrenaline and noradrenaline on both, the normal and the chronically denervated dilator muscle. Acetylcholine did not enhance the contractions by adrenaline and noradrenaline in the presence of atropine. Choline in a concentration of 5.10−6 M had no effect whereas concentrations of 5.10−5 M were slightly effective.