Untersuchungen über die Anaphylatoxin-Tachyphylaxie und über ihre Bedeutung für den Ablauf echter anaphylaktischer Reaktionen

Abstract

Rat plasma anaphylatoxin (AP) showed the same biological activity when activated by agar agar or by sephadex G 75. Both samples of AP produced tachy-phylaxis against each other. In guinea pigs an injection of 0. 3-0. 4 ml of AP/100 g produced a lethal shock. The same amount of AP was sufficient to produce tachyphylaxis after protracted injection. In tachyphylactic guinea pigs a reduced reaction to AP could be demonstrated for a period exceeding 24 hrs. In this state of tachyphylaxis the true anaphylactic shock was neither abolished nor modified. Also repeated injections of AP for several days had no effect on the anaphylactic shock of guinea pigs. On isolated organs of guinea pigs (as ileum, uterus, pulmonal artery, cardiac atria and the blood vessels of the hind leg) AP caused stimulation and subsequent tachyphylaxis. Normal sensitivity towards AP was generally restored in isolated organs within a rather short interval. The state of tachyphylaxis toward AP did not interfere with Schultz-Dale-re-actions. Isolated organs of the rat which are not sensitive to hista-mine (ileum, A. pulmonalis, uterus) did react to AP. They failed, however, to show significant tachyphylaxis. AP caused stimulation and subsequent tachyphylaxis in the chicken-amnion which is devoid of nervous tissue. AP-tachyphylaxis is not caused by an exhaustion of histamine-stores. AP does not participate in the true anaphylactic reaction of the guinea pig. It seems probable that histamine is liberated in the anaphylactic shock from different stores than in the AP-shock. AP has further effects exceeding thos which can be explained by a liberation of histamine.