Introduction: The level of intracellular cyclic nucleotides is a regulatory factor in a variery of immune processes. Increases in intracellular cyclic AMP (cAMP) and/or cyclic GMP (cGMP) concentration by the inhibition of phosphodiesierase have been shown to modulate the inflammatory response. Amnnone is a clinically used positive imxropic agent which elevates intracellular cAMP and cGMP levels by selective inhibition of the phosphodiesterase HI isoenzyme. In the current study, we investigated the effect of various concentrations (1-300 |iM) of amnnonc on lipopolysaccrande-induced production of pro- and anti-inflammatory cytokines and of nitric oxide (NO) in vitro. We also investigated whether the drug affects lipopolysaccharide-elicited nuclear transtocation of the nuclear factor-KB Methods: The murine monocyte/macrophage cell line J774.1 was grown in DMEM supplemented with 10 % fetal calf serum, 100 U/ml penicillin, and 100 |ig/ml streptomycin. Cells were treated with various concentrations (1-300 uW) of amrinone or drug vehicle 30 min prior to lipopolysaccharide challenge and thereafter with lipopolysaccharide (1 ng/ml - 10 ug/ml) for 24 h. At 24h, TNF-a, interleukin-10 and nitrite were measured in the supernatant and viability was measured with the MTT method. Cytokines were measured with ELISA, nitrite by the Griess reaction. Results: In cultured murine J774.1 macrophages, 1 ng/ml-10 Ug/ml of lipopolysaccharide from Escherichia colt O5S:BS induced production of tumor necrosis factor-a (TNF-a), interleukin-10, and nitrite (breakdown product of NO). Pretreatroent of cells with amrinone caused a dose-dependent suppression of TNF-a production in the concentration range of 1-100 uM. Furthermore, this drug suppressed NO production in the range of 30-300 (iM. Similar to the results in the JT74.1 cells, amrinone also inhibited TNF-a and NO production in the range of 10-100 uM in primary rat peritoneal macrophages. At 300 fiM. but not at lower concentrations, amrinone inhibited interleukin-10 production in lipopolysaccharide-treated J774.1 macrophages. Pretreatment of the macrophages with 100 and 300 uM amrinone increased the lipopolysaccharide-elicited translocation of the nuclear factor-KB. Conclusions: Our results indicate that the phosphodiesterase HI inhibitor amrinone modulates the production of many pro- and anti-inflammatory factors in macrophages. These immunomodulatory effects may contribute to the clinical profile of the agent.
|Original language||English (US)|
|Journal||Critical care medicine|
|Issue number||1 SUPPL.|
|State||Published - Dec 1 1998|
ASJC Scopus subject areas
- Critical Care and Intensive Care Medicine