Egg deposition of the intestinal nematode Heterakis spumosa: stimulation by soluble colon factors of mice.

The nematode Heterakis spumosa lives and develops in the upper colon of mice. The colon mucosa contains soluble factors that significantly increase release of eggs by female H. spumosa in vitro. Egg release is stimulated more when colon factors are prepared from mice harboring adult H. spumosa. Also, soluble factors stimulating egg release can be prepared from homogenates of H. spumosa but are not contained in H. spumosa-conditioned medium. Moreover, soluble factors from the small intestine of mice infected with Heligmosomoides polygyrus also stimulate egg release by H. spumosa females in vitro to about the same extent as soluble factors from the colon of H. spumosa-infected mice. Our data suggest that colon factors are involved in the regulation of egg deposition of H. spumosa, the efficiency of these factors is increased by intestinal inflammation, and that these factors are accumulated by H. spumosa worms.