The Effect Of Early Enteral Nutrition On The Intestinal Mucosal Barrier And Lung Injury In Rats With Severe Acute Pancreatitis

Objective:To investigate the influence of early (12 hours after the model made ) enteral nutrition on the intestinal mucosal barrier and lung injury in rats with severe acute pancreatitis.Methods:48 healthy male Sprague-Dawley rats (180-200g weight) were randomly allocated into four groups: sham operation group(S group); parenteral nutrition group(PN group); enteral nutrition gived 12h after operation (EEN group); enteral nutrition 24h gived after operation (EN group); In addition,32 healthy male Sprague-Dawley rats (180-200g weight) were randomly allocated into above- mentioned four groups to observe the survival rate among 5days;The model of SAP was induced by injected 1ml of 3.8%sodium taurocholate beneath the pancreatic capsule.Sham-operated animals was operated as the SAP group,but nothing was injected, pancreas was just flipped and striked gently a few times.Rats were killed by abdominal aorta exsanguination at 3d and 5d after operation .The levels of serum amylase were measured,other blood serum for ELISA and DAO and D-lactate , assay was restored at -80℃, pancreatic and lung and ileum tissue was fixed in 4% formalin, the expression of lung TNF-αprotein was examinated by immunohistochemistry, and observed the effects of early enteral nutrition on them.Results:1. Four groups of rats 5d survival rate: the survival rate of rats of S Section 5d was 100%,the PN, EN, EEN group were 50%, 62.5%, 75%, S group campared with the other three group had significantly difference (P<0.01); and PN, EN, EEN group compared with each other had no significant difference (P>0.05),which shows that early enteral nutrition is security.2. Serum amylase change: After the model ,the level of serum amylase of PN,EN and EEN group in various time points were significantly higher than the S group,had significant statistical difference (P<0.01); at all time points, EEN and EN group campared with PN group, although the amylase were lower, but had no statistical significance (P>0.05); EEN group campared with EN group had no difference (P>0.05).3. Pancreatic histological score: the S group, PN,EN and EEN group at different time points were significantly increased , compared with the S group had significant difference (P<0.01);and PN group, EN, EEN group score were lower, EEN 3d group, EN 5d group compared with PN group at corresponding time point had significant differences (P<0.05); in EEN group 5d, when compared with the PN group had significantly difference (P<0.01), EEN group compared with the EN group had difference (P<0.05).4. on the fifth day, PN group mucosa thickness and villus height are significantly lower than the EEN group, the difference was significant (P<0.01); the mucosa thickness and intestinal villi height of EEN group and EN group had significant difference (P<0.05) .5.Ileal Electron microscopy change: on the third day , PN group Microvilli reducing,arranged disorderly, tight junctions was broaden;on the fifth day , PN group Microvilli less,arranging disorderly, tight junctions swelled and destructed. on the third day , The EEN and EN group Microvilli reducing,arranging disorderly, but the tight junctions was normal. on the fifth day , The EEN and EN group Microvilli increasing ,arranging tidly, the tight junctions was normal.6.Lung morphological change: On the third day,obviously swelling of alveolar septa,interstitial hyperemia,hemorrhage,a lot of inflammatory cells infiltration,Pulmonary realvariable,bulla were observed in the PN,EN,EEN group. On the fifth day,obviously swelling of alveolar septa,interstitial hyperemia, hemorrhage, a lot of inflammatory cells infiltration,Pulmonary realvariable,bulla were still observed in the PN,EN and EEN group,but better than the third day. The PN group is more serious than EEN and EN group,but had no difference(P>0.05). The EEN and EN group also have no difference(P>0.05).7. Serum TNF-αchange: the serum level of TNF-αof PN,EN and EEN group compared with the S group in all time points had significantly differences (P<0.01); EEN 3d group, EN 5d group and PN group compared with each other in corresponding time point had significant difference (P<0.05); in 5d EEN group compared with PN group had significant statistically differences (P<0.01), EEN group compared with the EN group had significant difference (P<0.05).8. Plasma D-lactic acid change: plasma D-lactate levels of S group rats was low, at each time point had no significant change, and at all time points significantly lower than the PN, EN, EEN group, the difference had significant statistical significance (P<0.01); on the 3d, 5d the plasma D-lactate level of EEN group was lower than the PN group, There was a significant difference (P<0.01); on the 3d when the EN group compared with PN group was significantly decreased, the difference was statistically significant (P<0.05); on the 5d when the EN group compared with PN group also decreased significantly, the difference was significant statistical significance (P<0.01); on the 5d the plasma D-lactate levels of EEN group compared with EN group had statistically significant (P<0.05).9. Serum DAO change: After the model made, S group in all time points had no significant change, PN,EN group in 3d , 5 d time point was significantly lower than the S group, had significant statistical differences(P<0.01); on the 3d when the EEN group compared with PN group was increasing, the difference was statistically significant (P<0.05); on the 5d when the EEN group compared with PN group also increased significantly, had significant statistical difference (P<0.01); the EN group compared with the PN group, the difference was statistically significant (P<0.05 ); on the fifth day the serum diamine oxidase levels of EEN group compared with was EN group had statistically significant (P<0.05).10.Lung TNF-αprotein content change: After the model PN, EN and EEN group TNF-αprotein content were significantly higher than the S group in all time points (P<0.01);the third day were the highest. The protein content of PN,EEN and EN have on difference(P>0.05).Conclusions:1. The results of our study demonstrated that early enteral nutrition was feasible and safe,and did not aggravate pathogenetic condition of pancreatitis,it may be applied at early period.2. Early enteral nutrition could protect intestinal mucosal barrier.3.The lung injury of EEN and EN group were better than PN group,but had no statistical significance.