Effect of dexmedetomidine on pyroptosis in rats with endotoxin-induced acute lung injury / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the effect of dexmedetomidine on pyroptosis in rats with endotoxin-induced acute lung injury (ALI).Methods:Sixty SPF male Sprague-Dawley rats, aged 6 weeks, weighing 200-220 g, were divided into 5 groups ( n=10 each) by a random number table method: control group (group C), ALI group and different doses of dexmedetomidine groups (D 1-3 groups). In ALI group and D 1-3 groups, LPS 5 mg/kg was intraperitoneally injected to establish endotoxin-induced ALI model.Immediately after establishing the model, dexmedetomidine 12.5, 25.0 and 50.0 μg/kg were intraperitoneally injected in D 1-3 groups, and the equal volume of normal saline was intraperitoneally injected in group C, once a day for 14 consecutive days.After the end of administration, the rats were sacrificed, the left bronchus was lavaged, and the left bronchoalveolar lavage fluid (BALF) was collected for determination of the concentrations of interleukin-1beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α) (by enzyme-linked immunosorbent assay), and the lung tissue was taken for determination of the wet/dry weight ratio (W/D ratio) and expression of cleaved-caspase-1, N-terminal of the spliceosome (GSDMD-N), IL-18 and IL-1β (by Western blot) and for microscopic examination of the pathological changes (with a light microscope). Results:Compared with group C, the W/D ratio of lung tissues was significantly increased, the concentrations of IL-1β, IL-6 and TNF-α in BALF were increased, the expression of cleaved-caspase-1, GSDMD-N, IL-1β and IL-18 in lung tissues was up-regulated ( P<0.05), and the pathological damage was aggravated in ALI group and D 1-3 groups.Compared with group ALI, the W/D ratio of lung tissues was significantly decreased, and the concentrations of IL-1β, IL-6 and TNF-α in BALF were decreased, the expression of cleaved-caspase-1, GSDMD-N, IL-1β and IL-18 in lung tissues was down-regulated in a dose-dependent manner ( P<0.05), and the pathological damage was significantly reduced in D 1-3 groups. Conclusion:The mechanism by which dexmedetomidine attenuates endotoxin-induced ALI may be related to inhibition of pyroptosis and reduction of inflammatory responses in rats.