Abstract
Arginine vasopressin can bind to high-affinity vasopressin V1a receptors in human leukocytes. This study aims to investigate the effects of arginine vasopressin on migration and chemotaxis of neutrophils and oxygen free radical release by human leukocytes. Neutrophils and monocytes were obtained from peripheral blood samples of ten healthy volunteers. Leukocyte migration was microscopically assessed in a modified 48-blind well microchemotaxis chamber, and respiratory burst activity was estimated using 2',7'-dichlorofluorescin diacetate in descending concentrations of arginine vasopressin. Arginine vasopressin stimulates migration of monocytes and neutrophils depending on concentration and on interaction with other chemoattractants. The strongest chemotactic responses of monocytes to arginine vasopressin were observed in the micro and nanomolar range and in the nanomolar range for neutrophils (p<0.001). Pre-incubation of leukocytes with arginine vasopressin decreased migration of leukocytes in a dose-dependent manner. Arginine vasopressin did not stimulate release of oxygen free radicals by neutrophils. Arginine vasopressin stimulates in a dose-dependent manner the migration of monocytes and neutrophils. However, pre-incubation of leukocytes with arginine vasopressin decreased the migratory response of monocytes and neutrophils to other chemoattractants. These findings may be of importance in the treatment regimen of patients with septic shock.