Published online Jul 7, 2015. doi: 10.3748/wjg.v21.i25.7742
Peer-review started: December 30, 2014
First decision: January 22, 2015
Revised: February 13, 2015
Accepted: March 27, 2015
Article in press: March 27, 2015
Published online: July 7, 2015
Processing time: 190 Days and 18 Hours
AIM: To examine the effects of pancreatic rest, stimulation and rest/stimulation on the natural course of recovery after acute pancreatitis.
METHODS: Acute hemorrhagic pancreatitis (AP) was induced in male rats by intraductal infusion of 40 μL/100 g body weight of 3% sodium taurocholate. All rats took food ad libitum. At 24 h after induction of AP, rats were divided into four groups: control (AP-C), pancreas rest (AP-R), stimulation (AP-S), and rest/stimulation (AP-R/S). Rats in the AP-C, AP-R and AP-S groups received oral administration of 2 mL/kg body weight saline, cholecystokinin (CCK)-1 receptor antagonist, and endogenous CCK release stimulant, respectively, twice daily for 10 d, while those in the AP-R/S group received twice daily CCK-1 receptor antagonist for the first 5 d followed by twice daily CCK release stimulant for 5 d. Rats without any treatment were used as control group (Control). Biochemical and histological changes in the pancreas, and secretory function were evaluated on day 12 at 24 h after the last treatment.
RESULTS: Feeding ad libitum (AP-C) delayed biochemical, histological and functional recovery from AP. In AP-C rats, bombesin-stimulated pancreatic secretory function and HOMA-β-cell score were significantly lower than those in other groups of rats. In AP-R rats, protein per DNA ratio and pancreatic exocrine secretory function were significantly low compared with those in Control rats. In AP-S and AP-R/S rats, the above parameters recovered to the Control levels. Bombesin-stimulated pancreatic exocrine response in AP-R/S rats was higher than in AP-S rats and almost returned to control levels. In the pancreas of AP-C rats, destruction of pancreatic acini, marked infiltration of inflammatory cells, and strong expression of α-smooth muscle actin, tumor necrosis factor-α and interleukin-1β were seen. Pancreatic rest reversed these histological alterations, but not atrophy of pancreatic acini and mild infiltration of inflammatory cells. In AP-S and AP-R/S rats, the pancreas showed almost normal architecture.
CONCLUSION: The favorable treatment strategy for AP is to keep the pancreas at rest during an early stage followed by pancreatic stimulation by promoting endogenous CCK release.
Core tip: In experimental acute hemorrhagic pancreatitis, feeding ad libitum without any treatment delayed biochemical, histological and functional recovery. Both pancreatic rest made by blocking cholecystokinin (CCK)-1 receptor and pancreatic stimulation caused by eliciting endogenous CCK release improved biochemical and histological alterations, except pancreatic secretory function. The favorable treatment strategy for acute pancreatitis (AP) is to keep the pancreas at rest during an early stage followed by pancreatic stimulation. Thus, high-protein meals should be avoided during the early phase after AP but protein meals may be important at later times to stimulate recovery of pancreatic function.