Deleterious effect of Helicobacter pylori infection on the course of acute pancreatitis in rats.

BACKGROUND

Helicobacter pylori (Hp) infection is involved in various gastroduodenal pathologies. Also, the potential role of Hp infection has been proposed in several extragastroduodenal disorders, such as cardiovascular, skin or immunological diseases. The role of Hp infection in acute pancreatitis has not been tested. The aim of this study was to determine the influence of Hp infection on the course of acute ischemia/reperfusion-induced pancreatitis in rats.

METHODS

Inoculation with CagA- and VacA-positive Hp or administration of vehicle were performed after visceral ischemia. Visceral ischemia was evoked by clamping of the celiac artery for 30 min. Four weeks later, after full recovery from primary ischemia-induced damage, acute pancreatitis was evoked by limitation of pancreatic blood flow (PBF) in the splenic artery for 30 min using microvascular clips. Rats were sacrificed 1 h or 1, 3, 5, 10, and 21 days after removal of the vascular clips. Hp infection was assessed by the urease test and gastric histology.

RESULTS

In Hp-negative rats ischemia followed by reperfusion caused acute pancreatitis as manifested by a reduction in PBF and pancreatic DNA synthesis, as well as by increases in plasma amylase, lipase, interleukin-1beta (IL-1beta) and interleukin-10 (IL-10). The morphological features of pancreatic tissue showed necrosis, strongly pronounced edema, hemorrhages and leukocyte infiltration. The maximal intensity of pancreatic damage was observed between the 1st and 3rd day of reperfusion, then pancreatic tissue underwent regeneration. Hp infection resulted in a significant reduction in PBF and an aggravation of pancreatic ischemia 1 h and 3 and 5 days after reperfusion. Plasma amylase in Hp-infected rats was significantly higher than in Hp-negative animals 1 h and 1 and 3 days after ischemia, whereas in lipase this significant difference was observed between the 1st and 3rd day. DNA synthesis in Hp-positive rats was additionally reduced 1 h and 3 and 5 days after ischemia. Also ischemia evoked an increase in serum IL-1beta and IL-10, and morphological manifestations of pancreatitis were additionally enhanced by Hp infection.

CONCLUSIONS

(1) Hp infection increases the severity of ischemia-induced pancreatitis; (2) Hp infection increases production of pro-inflammatory IL-1beta, and (3) Hp infection aggravates disturbances in pancreatic microcirculation in acute pancreatitis.