ABSTRACT
Objective To establish a hypothermic pleural effusion model with SD rats,and to observe the relationship between hypothermic pleural effusion production and cold water immersion duration.Methods Sixty male Sprague-Dawley rats of(290.3 ± 7.5) g were randomly divided into experimental group(n =50) and control group(n =10).The experimental group was divided into group A1,A2,A3,A4 and A5 according to the different immersion time with 10 rats in each group.The experimental group was placed in a self-made cylindrical erected rat holders and then immersed in cold water at (20 ±0.2) ℃.The soaking depth was the level of clavicle of the rats.Group A1 and A2 were respectively removed and anesthetized after immersing 12 hours and 24 hours,and the serum and pleural effusion were collected to detect total protein and lactate dehydrogenase concentration.The remaining rats of experimental group were rewarmed by incubating at 37 ℃ for 1 hour.Group A3,A4 and A5 were respectively anesthetized at 12 hours,24 hours and 36 hours after the initiation of rewarming for detecting the serum and pleural effusion.The control group was directly anesthetized to collect serum to detect total protein,lactate dehydrogenase concentration.The pleural effusion quality was analyzed by Light standard.Results There was no obvious pleural effusion in normal rats.The amount of pleural effusion in the group A2 was higher than that in the group A1.After the rewarming,the amount of pleural effusion gradually decreased with the prolongation of time,and disappeared 36 hours later.Pleural effusion total protein/serum total protein was about 50％ in group A1,while it was more than 50％ in the group A2,A3 and A4.Pleural effusion lactate dehydrogenase/serum lactate dehydrogenase were all less than 60％ in each experimental group.The pleural effusion lactate dehydrogenase of experimental group was 2 times greater than that of the control group.Conclusion The method of establishing hypothermia pleural effusion SD rats model by immersing in 20 ℃ water is stable and reliable.The pleural effusion increased with the prolongation of the cold water immersing.After rewarming,the pleural effusion was gradually absorbed and then dispeared.