Effect of growth hormone on the metabolic activity of phagocytes of peripheral blood in pituitary dwarfs and acromegaly.

The increase of metabolic activity pf phagocytes estimated by nitrozolium reductase activity is often employed to distinguish between bacterial and non-bacterial febrile disorders. However, false responses has been also observed. The possible role of serum growth hormone in the activation of tetrazolium reductase activity in patients with pituitary nanism or acromegaly was studied. In isolated peripheral granulocytes of pituitary dwarfs the reductase activity was low at resting conditions as well as after starch stimulation of phagocytosis. Two hours after i. m. administration of human growth hormone the resting and stimulated tetrazolium reductase activity was significantly increased (P less than 0.05, and P less than 0.01, resp.). The increase of both activities was found also in patients with active acromegaly. A moderate increase of tetrazolium reductase activity was observed after adding of growth hormone to isolated granulocytes in vitro (P less than 0.01). These results suggest the stimulatory role of growth hormone in regulation of respiratory burst activity of peripheral granulocytes.