Mast cells in neuromuscular diseases.

The lectin Dolichos biflorus agglutinin has been used to identify mast cells in normal skeletal muscle and to investigate changes in their number in a wide range of human neuromuscular diseases and in rat muscle damaged by the local anaesthetic bupivacaine. Few mast cells were found in the perimysium of normal skeletal muscle but numbers were increased in human muscle biopsies which showed necrosis and regeneration of fibrosis. In bupivacaine-induced muscle damage, increased mast cell counts occurred during the necrotic phase and particularly during the phase of active regeneration. In addition, increased numbers of mast cells were observed in the underlying histologically normal muscle. These results show that mast cells are influenced by pathological changes in skeletal muscle and, in view of the known functions of mast cells in other tissues, it is possible that they are capable of modulating disease processes in muscle.