Mast cell restoration. A study of the rat peritoneal mast cells after depletion with polymyxin B.

The recovery of mast cells in adult rats after depletion induced by polymyxin-B has been studied. At days 17-18 after depletion the number of identifiable mast cells in the peritoneal fluid reached 3 X 10(6) cells/rat. Mast cell granule constituents such as histamine, heparin, mast cell protease and beta-glucuronidase increased steadily during the observation period, whereas the amount of N-acetyl-beta-glucosaminidase decreased during the first 2 weeks and was thereafter constant. At 2 weeks after depletion the peritoneal mast cells were biochemically restored. From 14 to 34 days (end of experimental period) cell growth occurred with a simultaneous accumulation of the various mast cell granule constituents.