ABSTRACT
Objective To explore the anti-inflammatory effect of antiflammin-2 (AF2) and recombinant peptide sequence 2(R2) on acute lung injury of mouse. To observe the expression of clara cell 16000 protein (CC16) and surfactant protein A (SP-A) in the lung of mouse inoculated with lipopolysaccharide (LPS) and the impact of AF2,R2,and glucocorticoids(hydrocortisone,HC) may have on the expression of the CC16 and SP-A in the lung of mice with acute lung injury. Methods Balb/c mice were inoculated with LPS (5 mg/kg) by intraperitoneal injection to set up ALI mice model. Mice weighed from 15 g to 16 g were grouped into control group, model group and treated groups respectively treated with AF2, R2 or HC. Mice in the control group were injected with physiological saline solution, while mice in the other four groups were inoculated with LPS to induce acute lung injury. Then animals in the treated groups were treated with AF2, R2 or HC each on a dose of 2 mg/kg also through intraperitoneal injection,while those of the control group and the model group, were given equivalent physiological saline solution as a placebo. The respiratory rate of all of these animals were recorded 6 hours after the injection. And at the time point of 12 hour,all the mice were sacrificed for a preparation of the whole lung tissue for the sake of a pathological investigation ,or for extractions of RNA for a semiquantitative analysis of the expression of CC16 and SP-A within the lungs. Results (1) An obvious attenuation of the respiratory rates of the three treated groups were observed when comparing with that of the mice in the model group without any anti-inflammatory treatment. (2) Remarkable extenuation of the extent of intra-alveolar and intersticial hemorrhage and infiltration of inflammatory cells were observed within the treated groups comparing with that of the model group. (3) An attenuate expressions of CC16 or SP-A were observed in the model group,while obvious uptrend of CC16 expression was observed in AF2 treated groups and increase of SP-A expressions were found in R2 and HC treated groups. Conclusion The anti-inflammatory effect of the peptide, AF-2 or R2, has been conformed on ALI mice model induced by LPS.
ABSTRACT
Objective To study the adrenal function in rats with pulmonary acute lung injury (ALI) induced by Escherichia coli (0111B4) . Methods ALI rat model was induced by intratracheal injection of E.coli (3 ml/kg,0111B4,(4.4-5.6) x 10~(12) CFU/L).ALI rats were then randomly divided into three groups,and each group had 10 rats.Mechanical ventilation was applied at three time points,6 hours,24 hours,and 36 hours after injection At each time point 8 rats were used as control with saline administered intratracheally.The plasma ACTH and corticosterone levels were measured after stimulated by 100 μg porcine ACTH.Results Compared with control group,the model group had a higher level of plasma ACTH at each time point (P < 0.01).The plasma ACTH level reached the peak at 24 hours.The model group had a higher level of plasma corticosterone at 6 hours (P < 0.01) and 24 hours (P <0.05),but had a lower level of plasma corticosterone at 36 hours (P < 0.05).The plasma corticosterone level reached the peak at 6 hours in model group,which was higher than 24 hours (P < 0.05).After stimulated by ACTH,the increased levels of corticosterone were lower in model group than those in control group (6 hours,P < 0.05; 24 hours and 36 hours,P < 0.01).Conclusions Adrenal dysfunction may occur at early stage of ALI in rats.With the disease developed,adrenal response to ACTH decreased.Low dose corticotrophin-stimulated test could evaluate adrenal function in rats with pulmonary ALI induced by Escherichia coli (O111B4).
ABSTRACT
Objective To establish pulmonary acute lung injury(ALI)model in rats.Methods ALI model was induced in rats by intratracheal Escherichia coli injection[3 ml/kg,O111B4,(4.0～6.0)×1012 CFU/L].Mechanical ventilation was applied 12,24,36,48 and 72 h after Escherichia coli injection,PaO_2/FiO_2 and dynamic compliance were recorded,and the normal control group was also subjected to mechanical ventilation.After the experiment,lungs were fixed with formalin to perform pathological examination.Results At 12,24,36,48 and 72 h,the PaO_2/FiO_2 were(30.71±7.95)kPa,(21.66±5.34)kPa,(21.09±4.75)kPa,(25.01±8.78)kPa and(33.82±8.02)kPa,respectively,which were significantly lower than that in the normal control group(63.82±3.03)kPa(P＜0.01).At 12,24,36,48 and 72 h,the Cdyn were(4.23±0.13)ml/(kg·kPa),(4.19±0.96)ml/(kg·kPa),(4.28±0.69)ml/(kg·kPa),(4.44±0.62)ml/(kg·kPa)and(4.58±0.35)ml/(kg·kPa)respectively,which were significantly lower than that in the normal control group(8.16±0.78)mL/(kg·kPa)(P＜0.01).At 12,24,36,48 and 72,the percentage of ALI was 71.4%,100.0%,100.0%,83.3%and 57.1%respectively,and the percentage of ARDS was 28.6%,85.7%,83.3%,66.7%,14.3%respectively.As for pathological examinations,predominance of alveolar collapse,fibrinous exudates,alveolar wall edema and neutrophil recruitment into the alveolar space was observed.Hyaline membrane formation was found.At 72 h,inflammation was relieved.Conclusion We successfully established pulmonary ALI/ARDS model in rats induced by intratracheal Escherichia coli injection,and acquired some useful information by observing the lung function and morphological changes at different time points.