Mast Cells Contribute to Flow Restoration by Bone Marrow Cell Transplantation in Rats With Ischemic Limbs

Abstract

The aim of this study was to assess whether mast cells are involved in the recovery of diminished cutaneous blood flow (CBF) by bone marrow cell transplantation (BMCT) in limb arterial occlusion. In a hindlimb ischemia model, CBF was measured by laser Doppler perfusion imaging in White spot (Ws) rats which genetically lack mast cells, and their wild-type with or without BMCT. After 14 days, tissue mast cell density was assessed by toluidine blue staining. To evaluate angiogenesis, we also determined CD 31-positive capillary density in the ischemic limbs.CBF in ischemic limbs decreased to 36 +/- 2% of nonischemic limbs, but 7 to 14 days later it naturally recovered to 65 +/- 2% and reached a plateau in both types of rats. BMCT further (P < 0.05) increased CBF with increases in tissue mast cell and capillary densities in wild-type rats, but not in Ws rats. Treatment with sodium cromoglycate, an inhibitor of mast cell degranulation, diminished the increases in mast cell and capillary densities, and CBF by BMCT in ischemic limbs of wild-type rats. Mast cells may not be involved in ischemia-induced natural angiogenesis and a partial recovery of CBF, however, they appear to be involved in the therapeutic angiogenesis by BMCT.