Release of a Histamine-Destroying Factor During Anaphylactic Shock in Guinea Pigs. ∗

Comment and conclusions

A state of shock can be induced by intravenous administration of the specific antigen into guinea pigs sensitized to crystalline egg albumin and anesthetized with pentobarbital sodium. The finding that histamine is released into the blood of guinea pigs during anaphylactic shock(4) has been confirmed.

It has been shown previously that aminoguanidine blocks the action of histaminase (5,6). Since aminoguanidine blocked the destruction of histamine in this study, it has been concluded that the factor in the blood responsible for destruction was diamine oxidase (histaminase). Code's group(2) arrived at a similar conclusion from their observations on rats.

The incubation period necessary to demonstrate destruction of histamine in blood from shocked guinea pigs is much less than that in rats. A period of 1 1/2 hours in all specimens was used initially in this study because of prior experience with rats. However, shorter incubation was tried after the first part of the study was completed. Destruction was as extensive at 1/2 hour as at 1 1/2 hours. The work of Arunlakshana and co-workers (7) suggests that the rate of destruction is even more rapid than this.

No histamine-destroying activity was demonstrated in blood secured before shock. However, such activity was present in shock blood regardless of the extent to which the histamine was increased. Blood drawn at varying intervals after the shocking dose showed histamine-destroying activity even when little or no increase in histamine could be demonstrated. This was especially true of the specimens secured at 15 to 30 seconds.

However, Boreus(8) found that blood histamine increased within 30 seconds after injection of the antigen. He also noted a reduction of about 50 per cent in the tissue mast cells at this time.