A study on relationship between interleukin-32 and Klebsiella bacillus pneumonia in rats / 中国中西医结合急救杂志

ABSTRACT

Objective To study the changes in interleukin-32 (IL-32) in rats with Klebsiella bacillus pneumonia and approach its significance. Methods Seventy-two Sprague-Dawley(SD)rats were divide into control group,model group and experimental group by the method of random digits table,then the experimental group was subdivided into 4 hours and 1,3 and 5 days experimental subgroups(each n=6). The rat model of Klebsiella bacillus pneumonia was established by injection of 0.3 mL Klebsiella bacterial suspension into the trachea. Before the establishment of the model in the experimental group,IL-32 inhibitory agent,protease activated receptor-2(PAR2) was injected into the abdominal cavity. After model establishment,at different time points,blood was collected via tail vein to observe the changes in serum levels of IL-32,tumor necrosis factor-α(TNF-α),IL-6 and IL-8 in all the groups. The lungs were removed and stained with hematoxylin-eosin(HE)method to investigate the histopathological changes of the lung tissues under the light microscope. Results Compared to the control group, with the prolongation of time the levels of IL-32,TNF-α,IL-8 and IL-6 were increased gradually in the model group,and reached their peaks at 3 days〔IL-32(ng/L)84.40±28.24 vs. 18.57±3.86,t=5.544,P=0.002;TNF-α(ng/L)79.27±14.64 vs. 17.82±3.86, t=9.994, P=0.000;IL-8(ng/L)55.85±10.90 vs. 16.66±3.76,t=8.544, P=0.000;IL-6(ng/L)56.65±2.57 vs. 28.48±2.11,t=19.693,P=0.000〕;PAR2 could inhibit above indexes significantly,there was statistical difference at 3 days compared with the model group〔IL-32(ng/L)54.13±6.68 vs. 84.40±28.24,t=2.560,P=0.046;TNF-α(ng/L)49.12±3.56 vs. 79.27±14.64,t=4.901,P=0.003;IL-8 (ng/L)22.95±2.52 vs. 55.85±10.90,t=7.204,P=0.000;IL-6(ng/L)36.49±2.63 vs. 56.65±2.57,t=13.443, P=0.000〕. Under the light microscope,the inflammatory changes in the lung tissue in experimental group were milder than those in the model group. Conclusion As a pro-inflammatory cytokine,IL-32 can induce the production of TNF-α,IL-6 and IL-8,and the inhibition of IL-32 production may play a role in suppression of the development of Klebsiella bacillus pneumonia.