Induction of intestinal mastocytosis in nude mice by repeated injection of interleukin-3.

The number of mast cells in various tissues of nude mice was examined after daily injection of Interleukin-3 (IL-3), which was purified from the media conditioned by WEHI-3B cell line. Repeated intraperitoneal injection of IL-3 caused a significant increase in the number of mucosal mast cells (MMC) in the epithelium of small intestine more than 30-fold and also to a lesser extent in the villous lamina propria of small intestine and caecum. The number of mast cells in the spleen, approximately 60% of which were formalin-resistant and were assumed as connective tissue type mast cells (CTMC), increased 3-fold by IL-3 treatment. Although statistically not significant, the number of mast cells in the ear skin also slightly increased.