Timing, route, and dose of administration of heparin-binding epidermal growth factor-like growth factor in protection against intestinal ischemia-reperfusion injury

Abstract

Purpose: We have previously demonstrated that heparin-binding epidermal growth factor-like growth factor (HB-EGF) is an intestinal cytoprotective agent. The current study examined whether HB-EGF is effective as salvage therapy as well as prophylactic therapy for intestinal ischemia-reperfusion (I/R) injury, whether intravenous administration is as effective as intraluminal administration, and whether increased benefits are seen with increasing dose.

Methods: Total midgut I/R injury in rats was achieved by occlusion of a first-order branch of the superior mesenteric artery for 60 minutes, followed by reperfusion for 6 hours. Rats were treated with HB-EGF 5 minutes before ischemia, halfway through the ischemic event, or 5 minutes after ischemia. Route of administration was tested by administering HB-EGF either intraluminally or intravenously. Seven different doses of HB-EGF were tested.

Results: Heparin-binding, EGF-like growth factor protected the intestine from injury when administered before injury and was also effective when administered during ischemia or even after injury. Intraluminal administration of HB-EGF was superior to intravenous administration. Increasing doses of HB-EGF resulted in a greater cytoprotective effect.

Conclusion: These data demonstrate that HB-EGF acts as an effective intestinal cytoprotective agent when administered intraluminally not only before injury, but also during injury and, most importantly, even after intestinal injury has already occurred. These findings support a basis for the prophylactic use of intraluminal HB-EGF in high-risk patients, as well as for the administration of HB-EGF to salvage patients in whom an intestinal insult has already occurred.