HPLC-ED measurement of endogenous catecholamines in human immune cells andhematopoietic cell lines

A rapid and simple HPLC-ED method is described to identify and measure cate cholamines (CTs) and their major metabolites in immune cells. Using this me thod, intracellular CTs were quantified in human peripheral blood mononucle ar cells (PBMCs), T and B lymphocytes, monocytes and granulocytes. Immune c ell subsets were separated by density gradient centrifugation and immunomag netic cell sorting. CTs were also found in the human hematopoietic cell lin es NALM-6 (pre-B) and (in smaller amounts) in Jurkat (T lymphoblastoid) and U937 (promonocytic). In cultured PBMCs, intracellular CTs were reduced by both the tyrosine hydroxylase inhibitor alpha -methyl-p-tyrosine and the ch romaffin granule depletant reserpine. In NALM-6 cells, both alpha -methyl-p -tyrosine and the dopamine-beta-hydroxylase inhibitor disulfiram reduced in tracellular CTs, supporting the presence of active synthetic pathways in th ese cells. Since sympathoadrenergic mechanisms play a key role in the inter actions between the immune system and the nervous system, these findings ma y be relevant for a better understanding of the neuro-immune network. (C) 2 000 Elsevier Science Inc. All rights reserved.