Effect of corticosteroids on argyrophilic premedullary thymocytes

Cells in the premedullar zone of the thymus contain serotonin and catecholamines and show argyrophilicity in the Grimelius test. Their cytoplasm is packed with granules. Glucocorticoids (hydrocortisone) provoke an increase in the number of argyrophilic premedullary cells and in their content of serotonin and catecholamines. Mineralocorticoids induce a prolonged (1-14 days) increase in the number of argyrophilic premedullary cells, enhance their degranulation, and increase their contents of serotonin (2-3 fold) and catecholamines. ©1997 Plenum Publishing Corporation.