“…Small amounts of thiopentone may increase the responses of isolated rat diaphragms to indirect and direct stimulation but high concentrations cause inhibition (Secher, 1951;Sirnes, 1954). Analogous effects have been produced by subnarcotic and anaesthetic doses in intact dogs, cats, rabbits and rats (Kraatz, Gluckman and Shields, 1953;Sirnes, 1954;Quflliam, 1955;Borgman et al, 1960). The stimulant action of thiopentone may cause a transient antagonism to tubocurarine and decamethonium but the main effect is a depression of muscular activity which potentiates paralysis by these drugs (Kraatz, Gluckman and Shields, 1953;Sirnes, 1954;Borgman et aL, 1960).…”