Inhibition of rats extramedullary liver erytropoiesis by hyperbaric oxygen therapy.

PURPOSE To research the hyperbaric oxygen therapy effects on rats' livers and spleens. METHODS 30 adult male Hotzman rats were used, being randomly distributed, by raffle, into 2 groups of 15 animals each: group 1 - control; group 2 - hyperbaric oxygen therapy. Group-2 animals underwent hyperbaric oxygen therapy for 120 minutes daily, 90 minutes of which were under pressure of 2.5 atmospheres. The first and last 15 minutes were used for gradual compression and decompression, respectively, for 20 days in a row. The livers and spleens of the animals from the two groups were taken out for histologic examination, on the day after the end of hyperbaric oxygen therapy in group 2 animals. Liver and spleen histologic changes of the animals from the two groups were compared by using Fisher exact test. P < 0.05 was regarded as a significant difference. RESULTS The only change in liver and spleen histology was the significant reduction in hepatic extramedullary erythropoiesis in the animals that underwent hyperbaric oxygen therapy (p < 0.05). CONCLUSION Hyperbaric oxygen therapy reduces hepatic extramedullary erythropoiesis in rats and doesn't jeopardize the other liver and spleen structures.