The Effect of Heparin on Anaphylactic Shock in Guinea Pigs.

Kyes and Strauser 1 have recently reported the inhibition of anaphylactic shock in pigeons by the intravenous injection of heparin 45 minutes preceding the shocking dose of antigen. They state that it is their belief that many of the symptoms of anaphylactic shock are the result of the formation of fibrin aggregates, and that if the formation of these aggregates be inhibited by a suitable reagent the symptoms will be reduced or eliminated.

In view of the striking results of these workers with pigeons, it seemed to us that it would be worth while to determine the effect of heparin on anaphylactic shock in guinea pigs. The animals were sensitized to horse serum twenty days before testing. Eight controls were tested for efficiency of sensitization, 6 of these dying with classical antemortem symptoms and showing the typical post mortem picture. Two animals exhibited symptoms of severe shock but survived. The guinea pigs receiving heparin were given 5 mg. of heparin in physiological salt solution intracardially for each 100 grams of body weight. The results obtained with these animals are shown in Table I.

As shown in the table, two of the heparinized guinea pigs receiving shocking doses of serum exhibited classical symptoms of shock, one of them succumbing with typical post mortem findings. It may be recalled that Kyes and Strauser report that 1 of 12 heparinized pigeons showed transitory symptoms. We do not feel that there is any relation bettyeen the size of the shocking dose and the occurrence of severe syniptonis in the heparinized guinea pigs, since some of the animals showed slight or no syniptonis, after receiving the same amount of sertini as that given to those which exhibited shock.