CIRCULATORY CHANGES FOLLOWING THE SUBCUTANEOUS INJECTION OF HISTAMINE IN DOGS

Abstract

Histamine shock in unanesthetized and etherized dogs was produced by subcutaneous inj. of histamine di-phosphate (ca. 10 mg. histamine base/kg.). Plasma vol., detd. with the dye dilution method (T-1824), was not markedly or consistently changed in spite of the rapid fall in blood pressure to shock levels (25 to 45 mm. Hg). In general the blood vol., calculated from plasma volume and arterial hematocrit measurements, increased. This increase was ascribed tentatively to mobilization of blood from the spleen and other blood depots. The clinical appearance and circulatory changes in this type of hista- mine shock differed markedly from changes observed in traumatic shock in unanesthetized dogs.