Zinc concentrations in pure populations of peripheral blood neutrophils, lymphocytes and monocytes

It is doubtful if the measurement of plasma or serum zinc is of value in assessing zinc status. Leucocyte zinc has been suggested as an alternative since it may be representative of tissue zinc stores; but in many studies poorly defined cell populations make interpretation difficult. This paper describes detailed techniques for the isolation and analysis of pure populations of neutrophils, lymphocytes and monocytes. Zinc concentrations (+/- 1SD) in normal subjects were 1.26 +/- 0.27 nmol/mg protein, 1.85 +/- 0.32 nmol/mg protein and 2.58 +/- 0.65 nmol/mg protein in neutrophils, lymphocytes and monocytes respectively. Fasting caused a significant decrease in neutrophil and lymphocyte zinc, and an increase in monocyte zinc. Supplementation of zinc-replete subjects with 135 mg zinc/day for 3 weeks had no significant effect on cellular zinc concentrations.