The effect of hyperbaric oxygenation on the distal intestine of rats subjected to ionizing radiation.

The current study was to test an experimental model of actinic lesions in the distal intestine of rats and to determine the possible protective effect of hyperbaric oxygen therapy (HBO2) in radio-induced lesions when concomitantly applied with ionizing radiation. Twenty-four Wistar rats were divided into four groups: � •�G1�(controlgroup);� � •�G2�(animalsirradiated);� � •�G3�(animalsirradiatedplusHBO2);� � •�G4�(onlyHBO2). The animals were evaluated for 28 days after the end of treatment and then euthanized. The distal intestine was resected for macroscopic and microscopic evaluation and immunohistochemistry. The animals in the G3�grouplostweightduringthetreatment;�alloftheanimalsintheG2�grouppresentedmacroscopicmucosal� lesionsupuntil�28�days;�theanimalsintheotherthreegroupsdidnotpresentmacroscopiclesions.�Microscopic� mucosallesionswereobservedinthespecimensoftheanimalstreatedwithionizingradiation;�intheanimals� fromtheG3�andG4�groupsthelesionswerelessintense.�Fortheimmunohistochemicalanalysis,�weobserved� thespecimenstakenfromG3�groupanimalshadmoreCD34+�cells.�Theexperimentalmodelprovedtobeuseful�