Effects Of Astragalus Injection On ICAM-1 Expression In Lung Of Rat With COPD By Cigarette Smoke Exposure

Background and ObjectivesObstructive Pulmonary Disease Chronic (COPD) is a common chronic respiratory system disease. In recent years, the morbidity and mortality of COPD are increasing year by year. However, there is still lack of effective clinical interventions. Studies have indicated that Astragalus can improve the body immunity, astragalus injection has been used in the treatment of cardiovascular and cerebrovascular diseases. This study intends to explore astragalus injection protection on respiratory function and the effects of astragalus injection on ICAM-1 expression in lung of rat with COPD by testing parameters of respiratory function, tissue morphology changes, ICAM-1 protein and mRNA expression in lung tissue. In order to provide scientific basis for the application of Astragalus Injection in the treatment of COPD.Methods1.30 SD rats were divided into 3 groups at random:chronic obstructive pulmonary Disease group(COPD group), astragalus injection group(astragalus group), normal control group(control group),10 rats in each group.2. Rats of COPD group were just exposured to smoke 2 times daily every time 30 mins for 80 days. Rats of astragalus group were treated by smoke exposure 2 times daily every time 30 mins for 80 days and intraperitoneal injection astragalus injection of 40 mg.Kg-1 since 41st first day Rats of control group were divided into normal control group with the no-treatment group.3. On the 81th day, all rats were anaesthesia by 4% chloral hydrate solution (10ml.kg-1), place endotracheal intubation and Left carotid artery catheterization, the diaphragm are connected with BL-420 biological signal collect and analysis system through tension transducer for recording respiratory curve.4. Rats in each group were detected by arterial oxygen partial pressure and arterial carbon dioxide partial pressure. The left ventricular blood was collected, and the arterial oxygen partial pressure and arterial carbon dioxide partial pressure were detected by blood gas analyzer.5. Then rats lung tissue samples were divided into parts for HE staining to test the morphological changes of lung tissue, enzyme-linked immuno sorbent assay to test the content of ICAM-1, immunohistochemical staining to test the expression of ICAM-1 and reverse transcription-polymerase chain reaction to test the level of ICAM-1mRNA in lung tissueResults1. The results of respiratory function related indicators showed that:The respiratory amplitude of COPD group was lower than astragalus group(t= 11.216, P=0.000), the respiratory amplitude of astragalus group was lower than control group(t=10.104, P=0.000). The respiratory frequency of COPD group was higher than astragalus group(t=11.672, P=0.000), there was no difference between the astragalus group and control group (t=3.925, P=0.000). The arterial partial pressure of oxygen of COPD group was lower than astragalus group(t=9.337, P=0.000), the arterial partial pressure of oxygen of astragalus group was lower than control group(t=13.263, P=0.000). The arterial partial pressure of carbon dioxide of COPD group was higher than astragalus group (t=16.112, P=0.000), the arterial partial pressure of carbon dioxide of astragalus group was higher than control group(t=12.053,P=0.000).2. The HE staining results surgessted that:In Control group:the lung tissue was clear, bronchial mucosa epithelium was complete, alveolar size was uniform, and the alveolar space was normal.In COPD group:it was visibled that interstitial hyperplasia of bronchial lumen stenosis, inflammatory cell infiltration, mucus secretions, enlargement of alveolar, alveolar interval variable width or interrupt and bullae of lung.In Astragalus group:there was also this pathological phenomenon in astragalus group, but it was lighter than COPD group.3. The results of ELISAI revealed that:The content of ICAM-1 in lung tissue homogenate of COPD group was higher than astragalus group(t=15.233, P=0.000), the content of ICAM-1 in lung tissue homogenate of astragalus group was higher than control group(t=12.108, P=0.000).4. The results of immunohistochemical staining displayed that:The ICAM-1 expression of astragalus group was lower than copd group (x2=8.72, P=0.000), the ICAM-1 expression of astragalus group was lower than control group (x2=7.93, P=0.000).5. The results of RT-PCR indicated that:The level of ICAM-1mRNA lung tissue homogenate of COPD group was higher than astragalus group (t=18.022, P=0.000), that of astragalus group was higher than control group (t=14.125,P=0.000)。ConclusionsAstragalus injection can reduce the expression of ICAM-1 in lung of rat with COPD, and improve the pulmonary ventilation and pulmonary ventilation, which is protection on respiratory function.