Enhancement of the responsiveness of vas deferens and ileum smooth muscle in sensitized guinea pigs: in vitro study.

Changes in the reactivity of the ileum (to histamine and barium chloride) and vas deferens (to acetylcholine and barium chloride), isolated from actively egg albumen-sensitized guinea pigs, have been investigated. The study was performed on 2 guinea pig strains: the Dunkin-Hartley strain, usually used as an airway allergic model, and the BFA strain. In actively sensitized guinea pigs of both strains, concentration-response curves exhibited a significant dose-dependent upward shift compared to those obtained in control guinea pigs. The maximal contraction strength calculated from these curves was significantly enhanced in both sensitized guinea pig strains, without a change in EC50 values. This study showed that the active antigen sensitization procedure involved several smooth muscle functions, and not exclusively the trachea.