RESUMO
Renal ischemia-reperfusion (IR) causes remote liver damage. Oxytocin has anti-inflammatory and antioxidant effects. The main purpose of this study was to evaluate the protective function of oxytocin (OT) in remote liver damage triggered by renal IR in rats. Twenty four rats were randomly divided into four different groups, each containing 8 rats. The groups were as follows: (1) Sham operated group; (2) Sham operated+OT group (3) Renal IR group; (4) Renal IR+OT group. OT (500µg/kg) was administered subcutaneously 12 and 24 hours before and immediately after ischemia. At the end of experimental procedure, the rats were sacrificed, and liver specimens were taken for histological assessment or determination of malondialdehyde (MDA), total oxidant status (TOS), total antioxidant status (TAS), paraoxonase (PON-1) activity and nitric oxide (NO). The results showed that renal IR injury constituted a notable elevation in MDA, TOS, Oxidative stress index (OSI) and significantly decreased TAS, PON-1 actvity and NO in liver tissue (p<0.05). Additionally renal IR provoked significant augmentation in hepatic microscopic damage scores. However, alterations in these biochemical and histopathological indices due to IR injury were attenuated by OT treatment (p<0.05). These findings show that OT ameliorates remote liver damage triggered by renal ischemia-reperfusion and this preservation involves suppression of inflammation and regulation of oxidant-antioxidant status.
RESUMO
OBJECTIVES: To determine the functional effects of methoctramine as an M(2) muscarinic receptor antagonist on isolated detrusor strips in vitro and bladder overactivity in vivo in rats. METHODS: A total of 114 Sprague-Dawley rats were used in the present study. Isolated rat detrusor strips were contracted by depolarizing the preparations with carbachol. Methoctramine was added to the tissue bath in increasing concentrations, and contraction inhibition was assessed. Isovolumetric contractions were evoked by electrical stimulation using a bipolar electrode. Efficacy against bladder instability was evaluated using the obstructed hypertrophied bladder model in the rat. The acetic acid bladder cystometry model was used to assess the efficacy of methoctramine in neurogenic detrusor overactivity. RESULTS: Methoctramine inhibited carbachol-induced bladder contractions significantly in isolated rat detrusor strips in a concentration-dependent manner. The amplitude of electrically evoked isovolumetric contractions was decreased significantly after methoctramine exposure. In vivo methoctramine administered intravenously significantly increased the voiding interval and bladder compliance. In addition, a decrease occurred in the number of spontaneous contractions during the filling phase in a model of neurogenic and obstruction-induced detrusor overactivity. CONCLUSIONS: M(2) antagonists in general may represent a new useful class of drug worth considering in the treatment of bladder overactivity.