The Problem of Abdominal Pain

Adrenaline Bronchoconstriction SIR,-My attention has been directed to your annotation (May 2, p. 557) under the above heading. The observation mentioned-namely, that adrenaline occasionally produces a bronchoconstriction-is not new. I observed such a constriction on many occasions when experimenting with the dog and measuring changes in the lumen of the larger bronchi by a direct method. This observation was recorded in the Journal of Physiology, 1936, 87, 298, and attention was also drawn to similar observations by M. Kiese (reference in the paper quoted). This action of adrenaline was found to be inconstant and unpredictable, and apparently unrelated to the manner of anaesthesia, though, of course, all drug actions are less marked with deep anaesthesia. I very tentatively suggested on that occasion that these results might be due to a secondary effect of the rise in blood pressure acting centrally in an unusual manner. In these animal experiments doses of the drug could be carefully graded, and were usually calculated to produce minimal changes in the cardiovascular system, but even so the proportionate rises in blood pressure were greater than would be the case in man. I am away from handy reference and have not yet read the paper quoted by your annotator; consequently I am unable to comment on their results from this point of view. However, all results of animal experimentation must be charily applied to man.-I am, etc., MAXWELL ELLIS.