The mechanism of corpuscle and serum anaphylaxis in the rabbit

Abstract

1. In rabbits dying acutely after a reinjection of corpuscles or after a primary injection of pig's corpuscles, the pulmonary circulation is found to be impermeable to saline solution under pressures so much greater than the maximal normal blood pressure in the pulmonary artery of that animal (over four times as great in some instances) that a sufficient immediate cause of death under these circumstances is seen in this physiologically complete interruption of the pulmonary circulation. 2. This obstruction of the pulmonary circulation is not due to an agglutination of the corpuscles and it may reasonably be referred to an effect on the muscular coat of the arterioles because the same phenomenon is produced by the injection of dissolved corpuscles and by the reaction of acute serum anaphylaxis—active and passive—and also by the introduction of the antigen into the pulmonary circulation after the latter has been perfused for five minutes with saline solution. 3. In the light of these observations, the local effect of Arthus would seem reasonably explicable as an area of infarction due to the interference with the blood supply to the area. 4. The cachexia and late death of rabbits in serum anaphylaxis offered, in the one instance of this kind, examined, a pathological picture consonant with the findings in acute anaphylaxis in the rabbit-the usual picture of a chronic interference with the circulation; namely, anasarca and greatly dilated right heart. 5. In the guinea-pig dying in acute anaphylaxis, the pulmonary circulation offers no increased resistance to the passage of fluid through it.