A respiratory reflex as affected by an anticholinesterase

Small doses of the potent anticholinesterase, TEPP, introduced via a cisternal puncture produce a marked potentiation of the respiratory reflex response induced by electrical stimulation of Hering's nerve in the dog. Larger doses of TEPP cause an inhibition of this reflex followed by respiratory failure. These experiments lend suggestive evidence that a neurohumoral mediator (e.g. acetylcholine) may be a component of respiratory control.

Muscle relaxants; effects on respiratory and circulatory dynamics

There are exceptions and variations to the general clinical rule that muscle relaxants depress respiration and have no effect on circulation. Variation may be attributed to differences in animal species, in individual response, in muscle affected, in drug used and in dose employed. Conclusions about muscle relaxants derived from animal experiments cannot always be assumed to apply to man. The "respiratory sparing" action of a muscle relaxant cannot be relied upon in any individual patient. Facilities for adequate artificial respiration must always be available when any dose of any muscle relaxant drug is administered. Muscle relaxants affect circulation by inhibition of parasympathetic and sympathetic ganglia, by anticholinesterase activity and by release of histamine.