The blood fibrin in canine anaphylaxis.

Abstract

Attention 1 was called to the fact that the delay or loss of the coagulability of the blood in canine anaphylaxis is apparently due to a reduction in the number of blood platelets, resulting in a reduction in the amount of thromboplastin necessary for the formation of a coagulum. With this in mind it was found possible to make a quantitative study of the blood fibrin by means of the simplified technique of Foster and Whipple 2 plus the addition of a thromboplastic agent to the clotting solution. This was supplied either in the form of a suspension of platelets, prepared as indicated in the previous paper, 1 or of a commercially prepared thromboplastin (Squibbs). Since the latter was the most convenient, this was generally used. The commercial product was filtered through a Gooch filter and was added in uniform quantities, 1 or 2 cc., to the clotting solution into which the oxalated plasma had been discharged. All the plasma samples, including the normal, from a given animal were treated in the same manner.

The animals were sensitized to horse serum, 0.3 cc. per kilo subcutaneously, and the shocking dose, 1 or 2 cc. per kilo of animal weight, was administered by intracardial injection. Anaphylaxis in dogs so injected almost invariably terminates fatally and marked pulmonary fixation, generally considered uncommon in canine anaphylaxis, is frequently observed at autopsy together with the hepatic congestion. The blood samples were also obtained by cardiac puncture.

Our results show that as a rule there is a well marked decline in the fibrin values immediately after the drop in blood pressure. The initial abrupt decline is generally followed by a more gradual one of variable duration. In animals which live sufficiently long, a gradual shift towards the normal level generally becomes evident.