[Effect of acidic fibroblast growth factor on mitogen-activated protein kinase activity in small intestinal epithelium after ischemia/reperfusion injury in rat].

ABSTRACT

OBJECTIVE: To investigate the effect of acidic fibroblast growth factor (aFGF) on p44/p42 mitogen-activated protein kinase (p44/p42 MAPK, extracellular signal-regulated protein kinase, ERK1/2) activity in small intestinal epithelium in rat after ischemia/reperfusion (I/R) injury and its relation with the change in small intestinal epithelium in rat after I/R injury as well as the change in proliferation of epithelial cells. METHODS: Superior mesenteric artery (SMA) was occluded to produce ischemia of the intestine for 45 minutes followed by reperfusion to reproduce I/R injury. One hundred and thirty-two Wistar rats were randomly divided into sham-operation group, I/R group, aFGF treatment group (4 microg of aFGF was injected into jugular vein after reperfusion), and PD98059 (antagonist of ERK 1/2) pretreatment group (7.5 microg of PD98059 was injected via tail vein before ischemia and 4 microg of aFGF was injected via jugular vein after reperfusion). The activity of ERK1/2 and proliferation rate of small intestinal epithelial cells were determined before ischemia and 15 minutes, 30 minutes, 1 hour, 2 hours, 6 hours, 12 hours and 24 hours after reperfusion. RESULTS: The activity of ERK1/2 in small intestinal epithelium was higher in aFGF treatment group than in I/R control group, and the proliferation rate in small intestinal epithelial cells was significantly enhanced in aFGF treatment group. PD98059, the specific inhibitor of ERK1/2, inhibited ERK1/2 activity and reduced the proliferation rate of small intestinal epithelial cells in aFGF treatment group. CONCLUSION: aFGF can promote small intestinal epithelial cell proliferation in I/R injury rats, and this may be related to activation of ERK1/2 in small intestinal epithelium.