The effects of thiouracil and thyroxine on the host-parasite relationship of Amplicaecum robertsi Sprent & Mines, 1960, in the mouse

Abstract

When infected with equal numbers of eggs of Amplicaecum robertsi normal male mice harboured more larvae than normal females. Treatment of the mice with thiouracil and thyroxine eliminated the differences between the sizes of the worm populations shown between the sexes in normal mice.Thiouracil treatment increased the susceptibility of mice to A. robertsi infection, but caused a stunting of the larvae. Thyroxine treatment had no effect on the host–parasite relationship.It is suggested that the differential ability of the larvae to hatch, penetrate the tissues of the host and migrate to the liver in thiouracil- and thyroxine-treated mice was responsible for the differences in the sizes of the larval populations observed.This investigation was carried out during the tenure of a Senior Research Fellowship from the Wool Research Board of Australia. I should like to thank Professor J. F. A. Sprent for his continued interest and Mr C. Wilkinson for his careful assistance.