Effects of penehyclidine hydrochloride on acute lung injury induced by blunt chest trauma and Toll-like receptor 4 expression in lung tissues in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of penehyclidine hydrochloride (PHCD) on acute lung injury (ALI) induced by blunt chest trauma and Toll-like receptor 4 (TLR4) expression in the lung tissues in rats.Methods Ninety-six male SD rats weighing 250-300 g were randomly divided into 3 groups ( n = 32 each)control group (group C), ALI group and PHCD group. ALI was induced by dropping a 300 g weight onto a precordial protective shield to direct the impact force away from the heart and toward the lungs in anesthetized rats according to the method described by Raghavendran et al. PHCD 2 mg/kg was injected intraperitoneally immediately after ALI was induced in group PHCD. Eight rats were selected at 2, 8, 12 and 24 h after ALI was induced, and arterial blood samples were collected for determination of the serum TNF-α concentration. Eight rats were selected at 8 h after ALI was induced, arterial blood samples collected for blood gas analysis and then the rats sacrificed. The lungs were immediately removed for determination of W/D lung weight ratio, myeloperoxidase (MPO) activity and TLR4 expression, and microscopic examination. Results The pH value and PaO2 were significantly lower, and the PaCO2, lactic acid level, MPO activity, W/D ratio, TLR4 expression and serum TNF-α concentration higher in groups ALI and PHCD than in group C (P ＜ 0.01 ). The pH value and PaO2 were significantly higher, and the PaCO2, lactic acid level, MPO activity, W/D ratio, TLR4 expression and serum TNF-α concentration lower in group PHCD than in group ALI ( P ＜ 0.05). The lung histopathologic damage was significantly ameliorated in PHCD group as compared with ALI group. Conclusion PHCD can protect the lungs against blunt chest trauma-induced ALI, and the down-regulation of TLR4 expression in lung tissues and reduction of inflammatory response are involved in the mechanism.