Toxocara canis-induced airway hyporeactivity in mice

Migrating larvae of the canine nematode Toxocara canis induce inflammatory responses in the lungs of infected mice. Histological examination of the lungs showed that mice, developed persistent multifocal inflammation in which eosinophils (eos), macrophages (M phi) and many lymphocytes were involved. Cuffing of blood vessels and bronchioles with mixed cell populations was also observed. Investigation into the response of isolated tracheae to cholinergic and beta-adrenergic receptor agonists demonstrated a significant decreased reactivity despite the pronounced involvement of eos and M phi. This hyporeactive state persisted for greater than or equal to 4 weeks p.i..