Vascular permeability increasing action of the saline extract of Dictyocaulus filaria--a preliminary report.

The cutaneous hypersensitivity reaction in sheep infected with Dictyocaulus filaria was investigated. The saline extract of the worms increased the cutaneous capillary permeability in both the infected and uninfected control animals. Similar increase in the permeability was also observed in uninfected healthy rabbits. The results suggest that the vascular permeability increasing action of the worm extract is, partly, due to histamine release.