“Malonate (1 mM), pentobarbital (0.5 mM), and … potassium uptake, and phenobarbital (0.5 mM), chlorpromazine (0.01 mM), atropine (1 mM), and procaine (0.1 mM), which have no effect on … 3.6 mM potassium on respiration and markedly reduce the large stimulatory effect of 60 mM potassium.”