The effect of growth hormone on the function of phagocytic human blood cells

Abstract

Effects of somatotropic hormone in different concentrations on the phagocytic activity of various populations of human lymphocytes and production of superoxide anion were analyzed in vitro. Blood cells were incubated in medium 199 with various hormone concentrations for 1 h at 37°C. Besides the traditional general parameters of phagocytosis, the counts of eosinophils, neutrophils, monocytes phagocytizing and not phagocytizing sheep red cells (SRC) were evaluated with regard to their activity (number of phagocytosed SRC) in the total pool of phagocytes (sum of all phagocytizing cells of different activity per mm³ blood). The spontaneous and zymosan-stimulated levels of superoxide anion were evaluated in the nitroblue tetrasolium reduction test. Addition of somatotropic hormone stimulated the total phagocytic activity of human leukocytes by activating al! types of phagocytes, but the hormone effect was different for different cells. Growth hormone exerted the greatest stimulating effect on monocytes, increasing 3-5-fold their role in total phagocytosis, in comparison with the control. Addition of growth hormone increased zymosan-stimulated production of superoxide anion but did not change its spontaneous level. The results indicate the probability and demonstrate the direction of the immediate effect of growth hormone on the functions of some populations of human peripheral blood leukocytes.