The phenotype of mast cell in primary adenoid liver tumor of rat and its relation to tumor cell

Abstract

Mast cells in adenoid liver tumors of 32 rats induced with nitrosomorpholine were observed ultrastructurally, and among them, some were studied immunocytochemically via immunogold techniques. Data indicating that mast cells which located in tumor tissues presented positive expression of rat mast cell protein (RMCP) I , indicating origination from the mucosa mast cells, while those in the connective tissues around tumors were largely stained negatively with either RMCP I or RMCP I antisera, with the exception of only a few cells showing positive RMCP I staining. Ultrastructural observation showed that mast cells in tumors contacted closely with the tumor cells. Membranes of the intracytoplasmic granules in these mast cells were fusing together. The content inside the granules were discharged and spread along the intercellular space between the tumor cells. There was not any lesion observed ultrasructurally in the tumor cells contacting with the mast cells. The significance of mucosa mast cells in adenoid liver tumors is briefly discussed.