[Excitatory effect of atropine on frog sympathetic ganglia]

Depolarization accompanied by an increase in the membrane conductance produced by atropine was studied in frog sympathetic ganglion neurons after activation of the receptors with different cholinomimetics. Atropine perfusion caused excitatory effects if perfusion with acetylcholine or with a mixture of suberildicholine and 5-methylfurmethide has been performed beforehand, i.e. an activation of both nicotinic and muscarinic receptors has taken place. After preceeding activation of nicotinic receptor with suberildicholine or muscarinic receptor with 5-methylfurmethide atropine caused no changes in electric properties of the membrane. It is supposed that atropine, acting on receptors changed after the action of agonists, can evoke their activation.