The transmitter released by stimulation of the bronchial sympathetic nerves of cats.

A study has been made of the transmitter released in a cat heart-lung preparation when the sympathetic chains were stimulated. The nervi accelerantes were always sectioned before stimulation. The transmitter appeared first in the pulmonary venous blood. In its actions on the heart-lung preparation, it resembled isoprenaline and not adrenaline. Chromatographic studies using three different solvents showed that 80 to 100% of this transmitter consisted of a catechol amine which had R(F) values which were identical with those of isoprenaline. Pharmacological studies failed to distinguish between the actions of this amine and those of isoprenaline, but clearly differentiated between those of the pulmonary amine, adrenaline, and noradrenaline.