To determine the in vitro effects of epinephrine, norepinephrine, and dobutamine on lipopolysaccharide (LPS)-stimulated production of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in blood from healthy dogs.
Blood samples from 9 healthy dogs.
Blood samples were incubated with LPS from Escherichia coli O127:B8 or PBSS (control) for 1 hour. Afterward, the samples were incubated with 10μM epinephrine, norepinephrine, or dobutamine or with saline (0.9% NaCl) solution (control) for 23 hours. Leukocyte viability was assessed by use of trypan-blue exclusion in blood from 2 dogs to ensure cell viability was not altered by the catecholamines. Tumor necrosis factor-α, IL-6, and IL-10 concentrations were measured in the supernatant in duplicate with a canine-specific multiplex bead-based assay. Blood samples from 2 dogs were used to create dose-response curves to evaluate whether the observed cytokine modulation was dependent on catecholamine concentration.
Incubation of blood with epinephrine and norepinephrine significantly increased LPS-stimulated production of IL-10, compared with the control. Epinephrine and norepinephrine significantly decreased LPS-stimulated production of TNF-α, compared with the control. Epinephrine and norepinephrine did not significantly alter LPS-stimulated production of IL-6. Dobutamine did not alter catecholamine production.
CONCLUSIONS AND CLINICAL RELEVANCE
Epinephrine and norepinephrine, but not dobutamine, had immunomodulatory effects on LPS-stimulated TNF-α and IL-10 production in blood from healthy dogs in this in vitro model of sepsis. Data suggested that dobutamine may have immune system-sparing effects in dogs with sepsis.