Comparison of histamine release from peritoneal mast cells derived from diabetic and control rats.

Clinical and experimental diabetes are associated with an increased number of mast cells and elevated tissue histamine concentrations. This study compared histamine release from peritoneal mast cells derived from diabetic and control rats. Experimental diabetes was induced by a single i.v. injection of streptozotocin (50 mg/kg body weight). Measurement of plasma glucose levels confirmed the diabetic state. Peritoneal mast cells were stimulated for 10 min with the lectin concanavalin A (0.5-100 micrograms/ml) in the presence or absence of phosphatidylserine, clinical dextran (0.6-1200 micrograms/ml) in the presence of phosphatidylserine, the calcium ionophore A23187 (0.1-1 microM) or the basic releasing agent compound 48/80 (0.1-10 micrograms/ml). Histamine release induced by these agents was similar in both populations. Further studies will compare the differences in histamine release from mast cells isolated from different tissues, e.g. heart and lung. In addition, physiological stimuli which are altered in the diabetic state (e.g. hyperosmolalar solutions and free radical generating systems) are under investigation.