Studies on the role of histamine and 5-hydroxytryptamine in immunity against the nematode Trichostrongylus colubriformis. V. Changes in amine levels in the intestine following infection of guinea pigs of different immune status.

A temporal relationship was established between the onset of expulsion of the parasitic nematode Trichostrongylus colubriformis from the intestine of both vaccinated and adoptively immunized guinea pigs with a sudden increase in small intestinal mucosal histamine to two or three times pre-infection levels. However, in guinea pigs whose capacity to expel T. colubriformis was inhibited by treatment with anti-lymphocyte serum, mucosal histamine remained at pre-infection levels. The results support previous findings which suggest an important role for histamine in the effector mechanism of the immune response of guinea pigs against T. colubriformis.