[Platelet catecholamine changes in patients with pheochromocytoma]

In patients with adrenal tumor, the importance of platelet catecholamine was examined. In patients with pheochromocytoma, not only preoperative catecholamine concentrations in blood and urine but also platelet catecholamine content were abnormally high as compared to patients with other adrenal tumors (pheochromocytoma for NE 3383 and E 311, no pheochromocytoma for NE 235 and E 24 pg.mg-1 protein). In the patient with pheochromocytoma, plasma catecholamine concentration showed its peak during the manipulation of the tumor during operation, and it decreased rapidly and returned to normal level the day after operation. On the other hand, platelet catecholamine content showed its peak after operation and returned to normal range on the 7th postoperative day. These results suggest that determination of platelet catecholamine content is useful for pre-operative diagnosis of pheochromocytoma, and that catecholamine in platelet modulates sudden fluctuation in plasma catecholamine concentration.