title: A novel, recovery, and reproducible minimally invasive cardiopulmonary bypass model with lung injury in rats.
abstract: BACKGROUND
  Cardiopulmonary bypass (CPB) has been shown to be associated with a systemic inflammatory response leading to postoperative organ dysfunction. Elucidating the underlying mechanisms and developing protective strategies for the pathophysiological consequences of CPB have been hampered due to the absence of a satisfactory recovery animal model. The purpose of this study was to establish a good rat model of CPB to study the pathophysiology of potential complications.
  
  
  METHODS
  Twenty adult male Sprague-Dawley rats weighing 450-560 g were randomly divided into a CPB group (n = 10) and a control group (n = 10). All rats were anaesthetized and mechanically ventilated. The carotid artery and jugular vein were cannulated. The blood was drained from the right atrium via the right jugular and transferred by a miniaturized roller pump to a hollow fiber oxygenator and back to the rat via the left carotid artery. Priming consisted of 8 ml of homologous blood and 8 ml of colloid. The surface of the hollow fiber oxygenator was 0.075 m(2). CPB was conducted for 60 minutes at a flow rate of 100-120 ml× kg(-1)×min(-1) in the CPB group. Oxygen flow/perfusion flow was 0.8 to 1.0, and the mean arterial pressure remained 60-80 mmHg. Blood gas analysis, hemodynamic investigations, and lung histology were subsequently examined.
  
  
  RESULTS
  All CPB rats recovered from the operative process without incident. Normal cardiac function after successful weaning was confirmed by electrocardiography and blood pressure measurements. Mean arterial pressure remained stable. The results of blood gas analysis at different times were within the normal range. Levels of IL-1β and TNF-α were higher in the lung tissue in the CPB group (P < 0.005). Histological examination revealed marked increases in interstitial congestion, edema, and inflammation in the CPB group.
  
  
  CONCLUSIONS
  This novel, recovery, and reproducible minimally invasive CPB model may open the field for various studies on the pathophysiological process of CPB and systemic ischemia-reperfusion injury in vivo.
authors.affiliation: Department of Cardiovascular Surgery, Air Force General Hospital, Beijing 100142, China.
authors.forename: Ling-Ke
authors.initials: LK
authors.lastname: Li
authors.affiliation: Department of Emergency, Shanghai Tongji Hospital, Shanghai 200065, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cheng
authors.affiliation: Department of Cardiovascular Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China.
authors.forename: Dong-Hai
authors.initials: DH
authors.lastname: Liu
authors.affiliation: Department of Pediatric Heart Center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Pediatric Heart Center, Beijing Anzhen Hospital, Capital Medical University, Beijing 100029, China. Email: zhuyaobin@yeah.net.
authors.forename: Yao-Bin
authors.initials: YB
authors.lastname: Zhu
authors.affiliation: Department of Cardiovascular Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China. Email: qchenhui@hotmail.com.
authors.forename: Chen-Hui
authors.initials: CH
authors.lastname: Qiao
authors.affiliation: Department of Pediatric Heart Center, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100037, China. Email: yanbozhang@126.com.
authors.forename: Yan-Bo
authors.initials: YB
authors.lastname: Zhang
mesh_terms: D000818:Animals; D002315:Cardiopulmonary Bypass / Q000379:methods*; D002746:Chlorpromazine / Q000627:therapeutic use; D004562:Electrocardiography; D007649:Ketamine / Q000627:therapeutic use; D055370:Lung Injury / Q000188:drug therapy / Q000601:surgery*; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D023421:Models, Animal; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D007649:Ketamine; D002746:Chlorpromazine