Radiographical and Histological Evaluation of Canine Decidual Reaction Induced by Intralumenal Injection of Bouillon Solution Mixed with or without Barium Sulfate

: Radiographical examination of the canine uterus intralumenally injected with barium solution revealed that barium was gradually condensed, segmented and distributed equally along the lumen like embryos in early pregnant uterus. Histological examination of the uterus intralumenally injected with bouillon solution alone showed a remarkable fish net- or tree branch-like growth of superficial glands towards the uterine lumen. The uterus injected with barium in bouillon solution induced two different histological changes: One consisted of cystic glandular hyperplasia in the whole endometrium, which was a so-called Swiss cheese endometrium, and the other was composed of a fish net- or tree branch-like growth in the superficial layer accompanied with cystic glandular hyperplasia in the basal layer. The latter represented endometrial differentiation into spongy layer, supraglandular layer and basal glandular layer, being similar to that during normal early placentation. These findings suggest that clotted barium in bouillon solution has stimulating effects on the uterus similar to those of embryos.