Study of the protective effect of dexamethasone on cisplatininduced ototoxicity in rats 1 9-Experimental SurgeryActa Cir Bras. 2017;32(10):873-880 AbstractPurpose: To evaluate the ability of dexamethasone to protect against cisplatin (CDDP)-induced ototoxicity. Methods: Male Wistar rats were divided into the following three groups: 1) Control (C): 6 animals received intraperitoneal (IP) saline solution, 8 ml/kg/day for four days; 2) C + CDDP: 11 animals received 8 ml/kg/day of IP saline and, 90 min after saline administration, 8 mg/kg/ day of IP CDDP for four days; and 3) DEXA15 + CDDP: 11 animals received IP dexamethasone 15 mg/kg/day and, 90 min after dexamethasone administration, received 8 mg/kg/day of IP CDDP for four days.Results: It was found that dexamethasone did not protect against weight loss in CDDPexposed animals. The mortality rate was comparable with that previously reported in the literature. The auditory threshold of animals in the DEXA15 + CDDP group was not significantly altered after exposure to CDDP. The stria vascularis of animals in the DEXA15 + CDDP group was partially preserved after CDDP exposure. Conclusions: Dexamethasone at the dose of 15 mg/kg/day partially protected against CDDPinduced ototoxicity, based on functional evaluation by brainstem evoked response audiontry (BERA) and morphological evaluation by optical microscopy. However, dexamethasone did not protect against systemic toxicity. 873Study of the protective effect of dexamethasone on cisplatin-induced ototoxicity in rats Capelo IOJ et al. Acta Cir Bras. 2017;32(10):873-880 874 kept in cages with free access to food and water and natural sleep and wake cycles.The animals were divided into three groups:Group 1 (n = 6) (Control; C): rats were treated on four consecutive days with saline solution at 8 ml/kg/day (total of 32 ml/kg). The animals were evaluated by brainstem evoked response audiometry (BERA) one day before (D0) and four days after (D4) treatment initiation.Group 2 (n = 11) (C + CDDP): rats were treated on four consecutive days with saline solution at 8 ml/kg/day (total of 32 ml/kg) and with CDDP at 8 mg/kg (total of 32 mg/kg) 90 min after saline administration. The animals were evaluated by BERA on D0 and D4.Group 3 (n = 11) (DEXA15 + CDDP): rats were treated on four consecutive days with dexamethasone at 15 mg/kg/day (total of 60 mg/kg) and with CDDP at 8 mg/kg/day (total of 32 mg/kg) 90 min after dexamethasone administration. The animals were evaluated by BERA on D0 and D4.Wistar rats underwent deep anesthesia with 80 mg/kg ketamine combined with 10 mg/kg xylazine. A previous otoscopy was performed, and animals with external and middle ear alterations were excluded from the study. Those with normal otoscopy received auditory evaluation (BERA) just prior to drug administration (D0). In all groups, the medications were injected intraperitoneally. In groups 2 and 3, the chemotherapy injection was performed 90 minutes after the initial injection of dexamethasone or saline solution. On the subsequent three days...

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