Histamine formation in the blood and bone marrow of the guinea pig

Abstract

The histamine content and the histidine decarboxylase activity of bone marrow have been studied in guinea pigs treated with foreign protein. In some experiments the effect of 6-methylprednisolone also was observed. Treatment of guinea pigs with foreign protein resulted in a 10-fold increase of both histamine concentration and histidine decarboxylating activity in the blood and bone marrow. Histamine levels and histidine decarboxylating activity were related to the number of basophils. A fairly constant relationship was found between the histamine content and the enzyme activity per basophil. The findings suggest that histamine is formed and to a certain extent also stored in the basophilic leukocytes.