Effects Of Vaporized Perfluorocarbon Therapy On Aquaporins Of Lung In Seawater Respiratory Distress Syndrome In Rabbits

Objective: To investigate the effects of vaporized perfluorocarbon (PFC) therapy on the expressions of lung AQP-1 (aquaporin, AQP) and AQP-5 in seawater respiratory distress syndrome (SW-RDS) in animal models.Materials and Methods:1. Totally 43 Female rabbits were randomly divided into five groups:â‘ conventional ventilation group (CMV group) (received VT: 8ml/kg, PEEP:0cmH2O);â‘¡positive end expiratory pressure group (PEEP group)(received VT: 8ml/kg, PEEP : 8cmH2O ) ;â‘¢PFC group (received VT: 8ml/kg, PEEP:0cmH2O , PFC 7ml/kg.h);â‘£PFC+ PEEP group (received VT: 8ml/kg, PEEP:8cmH2O, PFC 7ml/kg.h) and control group (free ventilation after made models), with each group having 8 rabbits. After tracheotomy, all the rabbits of the five groups were ventilated with PB 840 ventilator (infant modes). And other 3 rabbits were killed directly to observe their pathohistological changes of lung tissues and immunohistochemical expression of AQP-1 in lung.2. To investigate the changes of respiratory mechanics, homodynamic mechanics and arterial blood gas indexes during and after the treatment and observation the pathohistological changes of lung tissues as well as the lung histological injury score by light microscope. Wet/dry weight ratio of left lung was measured to evaluate the extent of lung edema.3.To approach the influence of vaporized PFC therapy to AQP-1 and AQP-5 by way of the expression of AQP-1 and AQP-5 mRNA in lung as well as the protein of AQP-1 .Results:1. The data of respiratory mechanics (including airway peak pressure, platform pressure and lung static compliance) were significantly getting worse and oxygenation index decreased after SW-RDS. After treatment, the indexes of PEEP, PFC and PFC+PEEP group obviously improved and the lung histological injury scores especially wet/dry weight ratio got better. Compared with CMV group, the differences were statistically significant. The animals in control group all died in 15 minutes after ventilation.2. The expressions of AQP-1 mRNA had no sttistial differences among 5 groups. There was a increasing trend in control group, CMV group, PEEP group, PFC group and PFC+PEEP group(their relative expressions were 100%, 107.18%, 133.79%,143.40% and 201.39%).3. The expressions of AQP-5 mRNA in CMV group, PEEP group, PFC group and PFC+PEEP group(their relative expressions were 15.28%,17.68%, 21.32% and 30.15%)were lower than contral group(100%), and the differences was statistically significant. In those four groups which received treatment, they have a increasing trend in CMV group, PEEP group, PFC group and PFC+PEEP group, although the differences was not statistically significant.4. Through immunohistochemical analysis, expressions of AQP-1 in lung indicate that there was lower levels in CMV group and PEEP group compare with those in PFC group and PFC+PEEP group.Conclution:1. Vaporized PFC and PEEP ventilation could obviously improve the indexes of oxygenation, respiratory mechanics and attenuate lung pathohistological injury especially lung edema. During treatment Vaporized PFC and PEEP ventilation have some combined influence at gaseous interchanging and attenuating lung pathohistological injury.2. Our results indicate that vaporized PFC therapy seemly promote the gene and protein expressions of AQP-1 and AQP-5 in lung, and this effect was enhanced by PEEP ventilation. AQP-1 and AQP-5 mRNA changed at the different time of the initial stage of lung injury.