Beneficial effects of intra-arterial and intravenous PGE1 in intestinal ischaemia–reperfusion injury

OBJECTIVES: Ischaemia–reperfusion (I/R) injury is encountered in conditions that diminish intestinal blood flow. There is no clinically feasible technique available for mucosal preservation. METHODS: One hundred Wistar rats were subjected to intestinal ischaemia for 15 and 60 min (I150, I600), followed by 1 and 7 days of reperfusion (R1d, R7d). Rats were subjected to ischaemia by clamping the superior mesenteric artery. Prostaglandin E1 (PGE1) (2.500 ng/kg intra-arterial bolus or 20 ng/kg intravenous infusion) was administered immediately prior to the commencement of the experimental period. Animals were divided into 20 groups: sham (laparotomy alone), sacrificed at 1 or 7 days; saline administration, 15 or 60 min of ischaemia, 1 or 7 days of reperfusion; prostaglandin E1 administration, 15 or 60 min of ischaemia, 1 or 7 days of reperfusion, each one for intra-arterial or intravenous administration. Ileal segments were excised and assessed for histopathological score, polymorphonuclear (PMN) leucocytes encountered and myeloperoxidase (MPO) activity measurement. RESULTS: I/R caused deterioration of histological characteristics. Prophylactic administration of PGE1 resulted in a significant decrease in the histological score compared with the respective saline group (analysis of variance, P < 0.005). In groups treated with PGE1, PMN leuco-cyte infiltration was lower for the 60 min of ischaemia group (I600/R1d *P = 0.026; I600/R7d P = 0.015). I150/R7d did not lead to a significant reduction in PMN infiltration (P = 0.061). Pretreatment with PGE1 attenuates MPO levels after intestinal I/R injury (P < 0.05). No differences were encountered between types of administration