Prevention of further cyclophosphamide induced hemorrhagic cystitis by hyperbaric oxygen and mesna in guinea pigs

Purpose: Hyperbaric oxygen therapy and mesna have been successfully used for hemorrhagic cystitis. We defined the protective effects of hyperbaric oxygen and mesna in further cyclophosphamide induced hemorrhagic cystitis in guinea pigs. Materials and Methods: A total of 48 male guinea pigs were divided into 6 groups. All groups received 2 doses of 68.1 mg./kg. cyclophosphamide intraperitoneally at the same time intervals but group 1 served as controls. Group 2 received cyclophosphamide only, group 3 received hyperbaric oxygen treatment (2.8 ATA for 90 minutes twice daily) before and the day after further cyclophosphamide, group 4 received 21.5 mg./kg. mesna intraperitoneally only with further cyclophosphamide, group 5 received hyperbaric oxygen and mesna with further cyclophosphamide, and group 6 received hyperbaric oxygen before initial cyclophosphamide, between the 2 doses and after the further dose of cyclophosphamide, and mesna on the days of cyclophosphamide. Results: Although mesna alone provided protection against cyclophosphamide induced cystitis in animal bladders, there was also significant damage compared with controls. When the uroprotective efficacy of mesna was supported with hyperbaric oxygen, bladder protection was promoted since mean histological scores and hematuria levels in this group did not differ from those in controls. Conclusions: According to this animal study using hyperbaric oxygen as adjuvant therapy in humans may be a better tool than mesna alone for the prophylaxis and treatment of cyclophosphamide induced hemorrhagic cystitis.