Mast Cell Changes in Animals Exposed to Cold

Abstract

A large increase in the number of mast cells was observed in perivascular areas of the mesentery in rats exposed to cold air of 2 or 6[degree]C for 2 or 4 weeks; in intervascular regions, the number decreased after 2 weeks but returned to initial values after 4 weeks at both 2 and 6[degree]C. The number of these cells increased in the skin of the abdomen but decreased greatly in that of the ear. Cause and meaning of these local (in the ear) and systemic (in the mesentery and abdomen) changes are discussed.