title: [Effects of polyethylene oxide at different concentrations on abdominal aortic blood flow and vascular resistance in rats].
abstract: OBJECTIVE
  To observe the effect of polyethylene oxide (PEO) solution at different concentrations on abdominal aortic blood flow and vascular resistance in rats and evaluate the safety and drag-reducing effect of PEO solution.
  
  
  METHODS
  Thirty-two rats were anesthetized and randomly divided into 4 groups. An ultrasonic flow probe was deployed on the abdominal aorta (5 mm above the common iliac artery) to measure the blood flow. The carotid artery pressure, iliac artery pressure, iliac vein pressure, central venous pressure (CVP) and ECG were also monitored. Saline or different concentrations of PEO [(1x10(-6)(low), 1x10(-5)(middle) and 5x10(-5)(high) g/ml)] were injected in the 4 groups of rats through the caudal vein at a constant rate of 5 ml/h for 20 min, and the changes of the vascular resistance was observed. RESULTS After injections of 1x10(-6) and 1x10(-5) g/ml PEO, the abdominal aortic flow increased significantly (P<0.05) while the vascular resistance was reduced (P(low)=0.052, P(middle)<0.001) as compared to those in the saline control group. Following the injection with 5x10(-5) g/ml PEO, the abdominal aortic flow increased to a threshold in the initial 4 min, after which it rapidly decreased to approach the baseline levels despite continuous infusion. Blood pressure remained stable after the injections except for 5x10(-5) g/mlPEO injection, which resulted in a reduction of the blood pressure by about 10 mmHg (P=0.014). The heart rate and CVP both underwent no significant changes following the injections.
  
  
  CONCLUSIONS
  The drag-reducing effect of PEO is closely related to its concentration, and compared with 1x10(-6) g/ml, 1x10(-5) g/ml PEO more effectively increases the blood flow and decreases the resistance. The effectiveness and safety of EPO are attenuated at a concentration higher than 5x10(-5) g/ml.
authors.affiliation: Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. huf2007@163.com
authors.forename: Feng
authors.initials: F
authors.lastname: Hu
authors.forename: Rong-sheng
authors.initials: RS
authors.lastname: DU
authors.forename: Dao-gang
authors.initials: DG
authors.lastname: Zha
authors.forename: Xiang-hui
authors.initials: XH
authors.lastname: Chen
authors.forename: Sheng-hui
authors.initials: SH
authors.lastname: Li
authors.forename: Bing-jie
authors.initials: BJ
authors.lastname: Zhou
authors.forename: Yi-li
authors.initials: YL
authors.lastname: Liu
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000502:physiology*; D001783:Blood Flow Velocity / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D008297:Male; D011092:Polyethylene Glycols / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014655:Vascular Resistance / Q000187:drug effects*
chemical_list: D011092:Polyethylene Glycols