A simple method of demonstrating muscular hypertonicity in anaphylactic shock

There has been lacking a suitable, simple method for demonstrating the muscular hypertonicity of anaphylactic shock in the intact organism. The following method answers the purpose admirably.

A sensitized pigeon of about 300 to 400 gm. body weight, and deprived of its food over night, is tied, back down, by fixing its legs and wings conveniently to a small operating board such as is used for guinea pigs. A head holder is unnecessary. Then a balloon made from a fish-skin condom, tightly attached to the end of a rubber catheter (No. 20 French) so as to form a balloon of about 10 by 4 cm. when distended, is introduced directly into the crop. The introduction is facilitated by first collapsing the balloon and then bringing it in close apposition to the catheter, which is stiff and carries the balloon with it. The catheter is now attached to a T-tube, which in turn is joined by rubber tubing to a small tambour. Then the balloon is distended by blowing air through one arm of the T-tube, and the system adjusted so as to keep the crop moderately well distended with air and yet permit a record of tonus changes from the tambour on a slow kymograph. Presently large peristaltic waves may begin, but these are not indispensable to the experiment. As soon as a control record is secured, the antigen is injected into a wing vein (right) in the axillary region, using an ordinary Luer syringe and needle of 23 or 26 gauge.

Almost immediately after injection of from $0.2 to $0.5 cc. of the antigen, there is a sharp and marked rise in tonus accompanied by other symptoms (lachrymation, salivation, dyspnea, convulsions, etc.) of anaphylactic shock.