Acta histochemica 109 (2007) 322—329 The effect of Misoprostol, a prostaglandin E1 analog, on apoptosis in ischemia–reperfusion-induced intestinal injury Ismet Topcu a,Ã , Seda Vatansever b , Ahmet Var c , Zuhal Cavus b , Serap Cilaker a , Melek Sakarya a a Department of Anesthesiology and Intensive Care, Celal Bayar University, Manisa, Turkey b Department of Histology and Embryology, Celal Bayar University, Manisa, Turkey c Department of Biochemistry, Celal Bayar University, Manisa, Turkey Received 7 July 2006; received in revised form 11 October 2006; accepted 19 October 2006 KEYWORDS Ischemia–reper- fusion; Misoprostol; Prostaglandin E1; Ileum; Apoptosis; Rats Summary The aim of this study was to investigate whether Misoprostol, a synthetic prostaglandin (PG) E1 analog, has any effect on the prevention of apoptosis in ischemia–reperfusion (I/R)-induced intestinal injury. Thirty adult male Wistar albino rats were divided into three groups: group I ¼ sham operated+saline; group II ¼ I/R+saline; and group III ¼ I/R+Misoprostol. Misoprostol (50 mg/kg/d) was adminis- tered as an intragastric meal for 3 days. The terminal ileum was collected for histological and biochemical investigations. Apoptotic cells were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labelled (TUNEL) reaction. Immunohistochemical analysis was performed to determine the distribu- tion of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS). Samples were also analyzed for malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). The number of TUNEL-positive cells was higher in group II when compared to the other two groups (po0.05). In group III this value was higher when compared to group I, but lower than group II (po0.05). iNOS immunoreactivity was not detected in ileum sections of group I animals, but moderate immunoreactivity was seen in group II and mild immunoreactivity in group III. The immunoreactivity of eNOS was moderate in ileum sections of all three groups. In ileum tissue, MDA was found to be higher in group II compared to group I (po0.05), but there was no difference in group III. SOD was not different between groups I and III, but was significantly higher in group II (po0.05). In our experimental model of I/R-induced intestinal injury, apoptosis is induced in enterocytes, whereas ARTICLE IN PRESS www.elsevier.de/acthis 0065-1281/$ - see front matter & 2007 Elsevier GmbH. All rights reserved. doi:10.1016/j.acthis.2006.10.007 Ã Corresponding author. Guzelyurt Mah. Ingolstadt Cad., Anadolu Konutlari No. 11, 45030 Manisa, Turkey. Tel.: +905052555996; fax: +90 236 2370213. E-mail address: topcuismet@yahoo.com (I. Topcu).