Effect Of Grape Seed Proanthocyanidin Extract In Rats Of Smoke Inhalation Pulmonary Injury

Objective:To set up an animal model apply to investigate smoke inhalation lung injury, which was of stability and repeatability. To observe the changes of rats'manifestation, the pathomorphism and the biochemistry in lung in use of assessing the reliability of the smoke inhalation models and analysising the development of smoke inhalation lung injury. To observe the safety of intraperitoneal injection of GSPE and thus to investigate the effects and mechanism of GSPE on smoke inhalation injury rats.Methods:1.Set up the model of smoke inhalation lung injury in ratsForty-eight male Sprague-Dawley rats weighing 220～250g were in experiment. After adaptive feeding for one week, 8 rats were taken out randomly as control group(A group). The rest models were established according by the methods of reported by Erfan Xie etc. in Burn Institute of the Third Military Medical University. They were exposed to dense smoke for 10minutes and then removed from the holder for 5 minutes. This process was repeated for three times. According to the standard of breathing rate greater than 30/min, the qualified rats were brought into the next experiment.2.GroupsThe qualified rats were randomly divided into two groups: B group, model group which were without treatment, received 3ml distilled water of intraperitoneal injection; C group: GSPE group, received 3ml solution of GSPE in distilled water (500 mg/kg) of intraperitoneal injection.3.Specimen selectionThe rats were anesthetized by 1% napental (30mg/kg)of intraperitoneal injection at 2h, 4h, 12h, 24h,respectively. Common carotid arteries (CCA) of rats were dropped tubes. 1ml blood from CCA was collected for blood gas analysis. After died for blood loss from CCA, the thoracic cavities of rats were opened and their lungs were taken out. Part of (1cm×1 cm)right upper lungs(RUL) was fixed by 10% formaldehyde for HE staining, the other part of RUL was weighed (W/D), and rest was stored in -70℃refrigerator for preparing tissue bomogenate.4.Index mensurationMeasure each group rats'W/D of lung. Homogenate all the left lungs after weighing to be 10% homogenate, and then get out the supernate atter centrifugating to measure the activity of SOD, GSH-PX, NOS as well as the content of MDA, NO of rats'lung in batch. Make pathological section to observe the pathological change in each stage.Result1.The rat'general state of health The breathing rate of B,C group were all quicker than 30/min after smoke inhalation injury. All of them manifested a series of symptoms including light and fast breathing, step down whereafter, and oral respiration, wheezing rale soon later, accompany depression and sluggish action. However the rats after interfere in GSPE manifested improved symptoms compare with model group.2.Assess the pattern of smoke inhalation of ratsThe rats'wet-to-dry weight ratio of lung tissue in model group was all higher than that in normal group significantly (P<0.05), however the arterial blood pressure of model group rats was lower than normal group obviously (P<0.05). The gross appearance of normal group rats'lung tissue was smooth and glossy, without bleeding point, which was different from the model group rats. There are obvious differences between the nomal rats and the smoke inhalation injury rats under the light microscope, the nomal group's tissue displayed complete structures and without hyperplasia in lung mesenchymal, but the injury rats'tissue manifested broken alveolar wall, hyperaemia of small vessels in lung, mass of nertrophilic granulocyte infiltrated in both pulmonary alveoli and lung mesenchymal.3.The effect of GSPE on pulmonary injury ratsEffects of GSPE on arterial blood gas of rats: All of the control group rats'arterial blood gas higher than 94mmHg, the model rats'PaO2 began to descend after smoke inhalation injury, it became the lowest when after they were injured: it was 27.6mmHg lower than the nomal group'. There was significant difference between the two groups. However the data of GSPE group showed the obviously effect to smoke inhalation injury rats: the PaO2 was heighten 21mmHg than the model group rats', and even the GSPE group rats'PaO2 recovered to normal at 24h after injury. There was significant difference between the GSPE groups and model group.Effects of GSPE on pulmonary moisture of rats: the water content in the lung of model group was more than that in the control group rats'lung, and there was significant difference between two groups (P<0.05). However, the water content in the lung of treated group was markedly little than that in model group'lung (P<0.05), and it was not significant more than that normal group (P>0.05).Effects of GSPE on biochemistry of smoke inhalation lung injury: Compared with the normal group, in the model group, the activity of SOD, GSH-PX decreased significantly (P<0.05), but compared with model group, in GSPE group, the activity of SOD, GSH-PX increased significantly(P<0.05). In model group, MDA activity was notably higher than that in control group(P<0.05), but in GSPE group, its activity was significantly lower than that in model group (P<0.05). TNOS activity and NO content increased markedly in model group compared normal group(P<0.05), but they decreased significantly in GSPE group compared model group(P<0.05)while increased still compared normal group(P<0.05).Effects of GSPE on pathological change of smoke inhalation lung injury: The HE stain showed that normal group rats'lung tissue was smooth and glossy without hyperplasia mesenchymal, but in model group the tissue manifested broken alveolar wall, hyperaemia of small vessels in lung, mass of nertrophilic granulocyte infiltrated in both pulmonary alveoli and lung mesenchymal. In the GSPE group the lung tissue was smooth and glossy with little inflammation cells compared the model group.ConclusionThe rats emerge typical symptoms of lung injury induced by smoke inhalation repeatedly, such as oral respiration, depression, long time hypoxemia and pathology change of lung injury.GSPE restrains hypoxemia effectively, enhance the activity of anti-oxidant, lighten pulmonary edema and inflammation. GSPE has significant effect on smoke inhalation pulmonary injury may be related to it's prominent ability of antioxidation.