Subject(s)
Arm/blood supply , Arm/innervation , Nerve Block , Peripheral Nerves , Arm/surgery , Brachial Plexus , Double-Blind Method , Female , Humans , Male , Median Nerve , Regional Blood Flow/drug effects , Ulnar Nerve , VasodilationABSTRACT
BACKGROUND: We hypothesized that posttreatment with 15-epi-16-parafluoro-phenoxy lipoxin A4 (ATL) could attenuate lipopolysaccharide (LPS)-induced acute lung injury in mice. METHODS: All the animals were randomly assigned to one of six groups (n = 6 per group). In the sham-vehicle group, mice were treated with 0.9% saline 60 min after they were challenged with saline. The sham-ATL group was identical to the sham-vehicle group except that ATL (0.7 mg/kg, IV) was administered, and the sham-ZnPP group was identical to the sham-vehicle group except that Zinc protoporphyrin IX (ZnPP, 25 mg/kg IV) was administered. In the LPS-vehicle group, mice were treated with vehicle 60 min after they were challenged with LPS. The LPS-ATL group was identical to the LPS-vehicle group but received ATL. The ZnPP-ATL-LPS group was identical to the LPS-ATL group, but ZnPP was administered 30 min before ATL. RESULTS: Inhalation of LPS increased inflammatory cell counts, tumor necrosis factor-alpha, and protein concentration in bronchoalveolar lavage fluid and also induced lung histological injury and edema. Posttreatment with ATL inhibited tumor necrosis factor-alpha, nitric oxide, and malondialdehyde production, with the outcome of decreased pulmonary edema, lipid peroxidation, and the infiltration of neutrophils in lung tissues. In addition, ATL promoted the formation of heme oxygenase-1 in the lung tissues. Heme oxygenase-1 activity was also increased in the lung tissues after ATL stimulation. The beneficial effects of ATL were abolished by ZnPP. CONCLUSIONS: This study demonstrates that posttreatment with ATL significantly reduces LPS-induced acute lung injury in mice.
Subject(s)
Aspirin/therapeutic use , Heme Oxygenase-1/physiology , Lipopolysaccharides/toxicity , Lipoxins/therapeutic use , Lung Diseases/enzymology , Acute Disease , Animals , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Aspirin/pharmacology , Heme Oxygenase-1/antagonists & inhibitors , Lipoxins/pharmacology , Lung Diseases/chemically induced , Lung Diseases/pathology , Lung Diseases/prevention & control , Male , Mice , Mice, Inbred C57BL , Random Allocation , Time FactorsABSTRACT
AIM: To investigate the role of Ca(2+) release-activated Ca(2+) (CRAC) channels in the ROS production in macrophages. METHODS: The intracellular [Ca(2+)](i) was analyzed by confocal laser microscopy. The production of ROS was assayed by flow cytometry. RESULTS: Both LPS and thapsigargin induced an increase in intracellular [Ca(2+)](i), either in the presence or absence of extracellular Ca(2+) in murine macrophages. The Ca(2+) signal was sustained in the presence of external Ca(2+) and only initiated a mild and transient rise in the absence of external Ca(2+). CRAC channel inhibitor 2-APB completely suppressed the Ca(2+) entry signal evoked by thapsigargin, and suppressed approximately 93% of the Ca(2+) entry signal evoked by LPS. The increase in intracellular [Ca(2+)](i) was associated with increased ROS production, which was completely abolished in the absence of extracellular Ca(2+) or in the presence of CRAC channel inhibitors 2-APB and Gd(3+). The mitochondrial uncoupler carbonyl cyanide p-trifluoromethoxy-phenylhydrazone and the inhibitor of the electron transport chain, antimycin, evoked a marked increase in ROS production and completely inhibited thapsigargin and LPS-evoked responses. Conclusions. These findings indicate that the LPS-induced intracellular [Ca(2+)](i) increase depends on the Ca(2+) entry through CRAC channels, and close functional coupling between CRAC and ROS production in murine macrophages.
