“The basal, as well as the veratridine‐stimulated, uptake of guanidinium was inhibited by the cholinergic antagonists (+)‐tubocurarine (Ki= 50 to 500 nM) and atropine (Ki= 5 to 30 μM) and the adrenergic antagonists phentolamine (Ki= 5 μM) and propranolol (Ki= 60 μM).”