Effect of different periods of hyperbaric oxygen on ischemia-reperfusion injury of rat small bowel

Abstract

PURPOSE: To determine whether hyperbaric oxygen (HBO) could effectively protect the small intestine mucosa against an ischemic insult, according to different periods of application. METHODS: The gut of 32 male rats was subjected to 60-min ischemia (clamping the mesenteric artery and vein); After they were further reperfused upon clamp opening during 60 min. Animal groups were as follows. GII = placed on HBO during the ischemia period; GIII = placed on HBO during reperfusion; GIV = treated with HBO throughout the ischemia-reperfusion period. Some animals (GI) did not receive HBO treatment at all and served as reference of ischemia-reperfusion injury (IR). HBO was carried out in a cylindrical acrylic chamber (2.0 ATA). Samples of small bowel were prepared for H.E staining for histological evaluations. RESULTS: The histological injury of mucosa was significantly less when HBO was administered during the ischemia period (17.6 ± 0.6) as compared with the IR (21.3 ± 1.8). HBO was not effective when applied during reperfusion (23.1 ± 2.1) or during the ischemia plus reperfusion period (18.7 ± 1.9). The thickness of the mucosa was preserved by HBO in ischemia (327.50 ± 30.23 µm) in comparison with the IR (172.79 ± 5.95 µm). In the periods of reperfusion (162.50 ± 6.05 µm) and ischemia plus reperfusion (296.49 ± 20.01 µm) the mucosa revealed a structural injury. CONCLUSION: Hyperbaric oxygen affects the ischemic insult of small bowel, being the favorable effect obtained when hyperbaric oxygen was administered early in the ischemic period.

Iloprost reduces colonic injury in ischemic colitis in rats

“…The cells proceed to the apoptosis which is a programmed cellular death required for physiologic homeostasis 16 . Bortoletto et al 17 claimed that ischemia increases apoptosis during intestinal ischemia and hyperbaric oxygen therapy cam protect the mucosa against the ischemia-reperfusion injury. Similarly Aslan et al reported that there is increased inflammation and apoptosis in ischemic bowel anostomoses and meselamine (5-ASA) administration decreased the inflammation in the ischemic area by suppressing the free oxygen radicals 18 .…”

Ischemia and reperfusion of rat small intestine using pentoxyfilline and prostaglandin E1

“…To repair this special area it is mandatory a tissue reperfusion. If this subtle interruption occurs partially or in the whole small intestine, with a high intensity, many times it is not possible to maintain even the basal metabolism and, consequently, there is cell death and tissue necrosis [1][2][3][4] . The intestinal mucosa in the small intestine, it is the first area to be severely affected in cases of ischemia.…”

A proposal of multiplace hyperbaric chamber for animal experimentation and veterinary use

“…Such equipment, used by other researchers [23][24][25][26] , even though it has shown effectiveness for experimental application, presents limitations in the number of animals that can be used in each session and is only suitable for small animals. From the technical point of view the possibility of the material to present fatigue in a precocious way and the instability of the different parts fixed by screws, lead to the high risk of inadequate pressurization (escape of gas) and even the explosion of the chamber.…”

“…The equipment and facilities are an upgrade in our research laboratories and can improve our further works in our research baseline [23][24][25][26] .…”