A Pharmacological Approach to the Cause of Asthma: (Section of Therapeutics and Pharmacology).

About four years ago I began the investigation of an obscure pharmacological problem which, though interesting enough from a theoretical standpoint, offered no hope that any result of general importance might emerge from it. In the course of the work a number of new observations have been made which, taken together, suggest that adrenaline in circulation in the body has a function in relation to the sympathetic system not hitherto assigned to it. The results indicate that the efficiency of the sympathetic nerve (that is to say the size of the response elicited by a given impulse passing down a sympathetic nerve) depends upon the amount of adrenaline in circulation in the blood. The pathological application of this arises from the consideration that in some persons the amount of adrenaline in circulation may be below normal; some evidence derived from asthmatic patients is in support of this, and there is some evidence that the amount of adrenaline in the blood of different cats differs. If the amount of adrenaline in different persons does indeed vary, it follows that those persons in whom the amount of circulating adrenaline is abnormally low will possess a relatively inefficient sympathetic system; they will be predisposed to asthma. Should any chronic inflammatory change develop, leading either to a direct or to a reflex diminution of the bronchiolar air way, these patients will be unable to dilate their bronchioles and will suffer an asthmatic attack. The conception of the predisposing cause of asthma as being a deficient secretion of adrenaline which enfeebles the sympathetic nerves suggests fresh methods of treatment for the alleviation of the disease, by the addition to the diet of the precursors of adrenaline.