Antimicrobial functions of human monocytes depend on concentration of glutamine in vitro

We investigated the impact of different concentrations of glycyl glutamine on antimicrobial functions of human monocytes in vitro. Generation of suproxide anion, phagocytosis and killing capacity were measured as an expression of antimicrobial activity after an incubation period of 38 h at glycyl glutamine concentrations of 0.0, 0.4, and 2.0 mmol/l respectively. For each of the tests, significantly higher results were obtained with concentrations of glycyl glutamine of 0.4 mmol/l as compared to 0.0 mmol/l (p < 0.01). Further increases of superoxide anion production (p < 0.05) and killing capacity (p = 0.053) were observed when glycyl glutamine concentration in the culture medium was raised to 2.0 mmol/l. Variation of glycyl glutamine concentrations in vitro significantly affects antimicrobial functions of human monocytes.