Effect of human interleukin-10 on the inflammatory cytokines in rats with ventilator-induced lung injury

Abstract

Objective To investigate the effect of human interleukin-10 (hIL-10) pretreatment effect on inflammatory factors in rats with ventilator-induced lung injury (VILI). Methods 36 healthy male SD rats, weighing 220 to 300 g, were randomly divided into three groups (n=12): control group (C group), high tidal volume mechanical ventilation group (H group) and hIL-10 treatment group (HI group). C group maintained spontaneous breathing for four hours after orotracheal intubation.In H group, VILI model was made by high tidal volume mechanical ventilation, atracurium infusion was used to inhibit spontaneous breathing and maintain muscle relaxation, small animal ventilator was used for mechanical ventilation, respiratory parameters: respiratory frequency was 40/min, duration of ventilation was four hours, inspiration time/expiratory time was 1∶3, positive end expiratory pressure was 0 cmH2O, inhaled oxygen concentration was 21%, tidal volume was 30 ml/kg, regulating according to the body weight.HI group was injected with hIL-10 (8 000 U/kg) through tail vein at 30 min before high tidal volume mechanical ventilation, C group and H group were given the same amount of saline.In each group, the rats were sacrificed after ventilation for four hours.The serum and bronchoalveolar lavage fluid (BALF) were collected to detect the concentrations of tumor necrosis factor-α (TNF-α), interleukin-8 (IL-8) and intercellular adhesion molecule-1 (ICAM-1) by enzyme-linked immunosorbent assay.The right lung tissue pathological slices were taken to observe the morphological changes by HE staining. Results The pathological changes were observed under light microscope.There was no obvious alveolar structure damage in C group.In H group, there were alveolar structure destruction, alveolar exudation, hemorrhage and interstitial edema, visible alveolar fusion, pulmonary septal thickening, inflammatory cell infiltration.In HI group, there was a certain degree of damage in lung tissue structure, a small amount of pulmonary septal thickening, but lighter than that in H group.Compared with C group, the concentrations of TNF-α, IL-8 and ICAM-1 in serum and BALF of H group and HI group were increased (P<0.05 or P<0.01). Compared with H group, inflammatory cytokine levels in the serum and BALF of HI group were significantly decreased (all P<0.01). Conclusions As an important anti-inflammatory factor, hIL-10 can reduce VILI in rats in a certain extent by regulating the inflammatory response of the lung and reducing the levels of inflammatory cytokines. Key words: Interleukin-10; Mechanical ventilation; Acute lung injury; Ventilator-induced lung injury