| ObjectiveAcute pancreatitis causes pulmonary oedema with the accumulation of fluid in the alveolar spaces,possibly due to reduced clearance.This study tested the hypothesis that acute pancreatitis decreases alveolar fluid clearance in a rat model of pulmonary oedema during acute pancreatitis.To investigate the hypothesis,the observation was carried out on the lung of the SAP rat model.Its goal was to find that how to change of alveolar fluid clearence,epithelial sodium channel and Na-K-ATPase.To answer that:1) How to AFC change in SAP?2)Which subtype adrenal receptor on the lung was related with the changed AFC?3)Which subtype epithelial sodium channel and Na-K-ATPase were changed in SAP?Methods1 How to induce SAP rat model.Acute pancreatitis was induced by a retrograde injection of 5%taurocholate sodium(0.2 mL)into the common bile duct.The sham group was only turn over duodenum and pancreas in the operation.The control group was normal without interference.The figure of pancreas and abdomen was recorded,the measurement of amylase and lipase was observed and the pathology of pancreas and lung was observed. The life-time figure was painting.2 to observe the change of alveolar fluid clearance in SAP.The lungs were isolated 4,24 and 48 h after the induction of acute pancreatitis and alveolar fluid clearance was measured in the absence of pulmonary perfusion.The lung was bathed in wet at 37℃and ventilated 100%oxygen for 1h.3 to observe how to be changed the adrenal receptor in alveolar fluid clearance at SAP-4h.Added the prazosin(α1 adrenal receptor antagonist),yohimbine(α2 adrenal receptor antagonist),prazosin+yohimbine,propranolol(βadrenal receptor antagonist) into the bovine solution and then measured the AFC at SAP-4h.4 to observe whether the endogenous catecholamine affect the alveolar fluid clearance or not?Before making the rat SAP model,we resected the bilateral adrenal grand.The rats were measure AFC5to measure ENaC and Na-K-ATPase mRNA at SAP-4h group.By quantitative real-time PCR we measured ENaC and Na-K-ATPase mRNA of lung in SAP-4h rat.ResultsAlveolar fluid clearance increased to 31.0±3.5%of instilled volume/h in rats with acute pancreatitis for 4 h compared with 17.3±1.0%of instilled volume/h in sham rats (P＜0.01),then returned to the control level 48 h after acute pancreatitis(16.0±4.1% of instilled volume/h).The plasma epinephrine levels increased to 25-fold higher in rats with acute pancreatitis for 4 h than in Sham rat group without acute pancreatitis. Prazosin(anα1-adrenergic antagonist,10-4 mol/L),yohimbine(anα2-adrenergic antagonist,10-4 mol/L)or a bilateral adrenalectomy inhibited the increase in part,a combination of prazosin(10-4 mol/L)and yohimbine(10-4 mol/L)completely inhibited the increase in alveolar fluid clearance in rats after acute pancreatitis for 4 h,whereas propranolol(aβ-adrenergic antagonist,10-4 mol/L)had no effect,α,γ-ENaC mRNA increase 3 times and 2 times,separately,but not Psubtype.αNa-K-ATPase mRNA increased 3 times than the normal.ConclusionEndogenous catecholamine stimulatedα-adrenoceptors and increased alveolar fluid clearance in rats with acute pancreatitis.α,γ-ENaC andαNa-K-ATPase mRNA increased.
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