Investigation of protective effects of dexmedetomidine in experimental acute renal failure model

Objective: Acute renal failure (ARF) is characterized by a rapid deterioration in renal function. Dexmedetomidine is an ?2 ? agonist which is suggested for short-term sedation ( <24 hours) and given as a continuous infusion in intubated and mechanically ventilated patients in intensive care units.Data regarding dexmedetomidine?s anti-inflammatory effects has been obtained from a few number of previous studies.The aim of this study is to investigate the potential protective activity of dexmedetomidine in experimental ARF model in rats..Method: Rats were randomized into 5 groups consisting of 7 rats.Group 1 ( Control, n=7) : Rats did not receive any medication.Group 2 ( Sham, n=7) : Saline was administered at equal volumes with dexmedetomidine (2.5 mL/kg) intraperitoneally (I.P) and 50 % hypertonic glycerol ( 8 mL/kg) intramuscularly (I.M) . to the rats.Group 3 ( Gli, n=7) : Saline at equal volumes with dexmedetomidine ( 2.5 mL/kg) (I.P) and 8 mL/kg of 50 % glycerol (I.M) were administered to the rats.Group 4 ( Gli + dex 50, n=7) : 50 µg/kg of dexmedetomidine (I.P) and 8 mL/kg of 50 % hypertonic glycerol (I.M) were administered to the ratsGroup 5 ( Gli + dex 100, n=7): 100 µg/kg of dexmedetomidine (I.P) and 8 mL/kg of 50 % hypertonic glycerol (I.M) were administered to the rats..All of the study subjects were sacrified 24 hours after drug administrations and the blood and tissue samples were collected.Blood urea nitrogen (BUN) and creatinine were assessed by spectrophotometric method, TNF-? and IL?6 assessment was performed using ELISA methodLight and electron microscobic assessments were used for hystopathological examinationsSamples were assessed hystopathologically with a three level score which is based on acute tubular necrosis hystopathological identifying criteria.0: No injury1: Injury less than 25 %2: Injury between 25 %-50%3: Injury more than 50 %Results: ARF was produced at the end of 24 hours in all rats which were administered glycerol ( groups 3,4 and 5)( p= 0.000) However, there were no significant differences in BUN and creatinine levels between the groups which were given dexmedetomidine ( groups 4 and 5) and glycerol (group 3) ( p>0.05). There were no significant differences in TNF-? and IL- 6 levels among groups ( p>0.05)In hystopathological assessments, acute tubular necrosis was determined in all glycerol administered groups ( groups 3,4 and 5), whereas there were no significant hystopathological differences among groups receiving dexmedetomidine ( groups 4 and 5). The scores determined as 0 in groups 1 and 2 were determined as 2, and 3 in groups 3,4 and 5. The scores were significntly different between groups 1,2 and groups 3,4,5.(p=0.000). there were no significant difference among groups 3,4,5.Conclusion: In our study, there was no significant difference at TNF-? ve IL?6 levels among groups. We could not determine any biochemical and hystopathological data showing protective effects of dexmedetomidine on development of toxic acute tubular necrosis in experimental acute renal failure model.Keywords: Rat, acute renal failure, glycerol, dexmedetomidine