Aşkın Hekimoğlu

Effect of melatonin on epididymal sperm quality after testicular ischemia/reperfusion in rats

OBJECTIVE To determine the effect of melatonin, a pineal secretory product that prevents testicular ischemia/reperfusion (IR) injury through its antioxidative properties, on epididymal sperm quality in a rat testicular IR injury model. DESIGN Experimental study. SETTING University pharmacology laboratory. ANIMAL(S) Fifty-six 8-week-old male Wistar albino rats. INTERVENTION(S) Left testicular artery and vein occluded for 1 hour; before the bilateral orchiectomy, the organ was allowed to reperfuse 30 days. Melatonin (10 mg/kg IP) or vehicle (1% ethanol in saline) was administrated for 10 minutes before reperfusion and for 1 hour after reperfusion. MAIN OUTCOME MEASURE(S) After 24 hours of reperfusion, the rats were decapitated, and the testicular tissue samples were obtained for histologic examination. In addition, after 30 days of reperfusion, the epididymal sperm concentration, motility, and abnormal sperm rates were determined in the sperm collected from the epididymis. RESULT(S) A statistically significant decrease in sperm concentration resulted from IR as well as an increase in sperm abnormalities, but the sperm motility did not change. Melatonin treatment did not prevent the IR-induced reduction in sperm concentration. However, melatonin treatment statistically significantly decreased the sperm abnormalities when compared with the IR injured samples. CONCLUSION(S) Melatonin may improve sperm morphology for a protective effect in IR-induced testicular injury.

Oxytocin ameliorates remote liver injury induced by renal ischemia-reperfusion in rats.

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.

Effects of melatonin on the serum levels of pro-inflammatory cytokines and tissue injury after renal ischemia reperfusion in rats

Abstract We investigated the changes in the serum levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6, the pro-inflammatory cytokines, and the possible effect of melatonin on the modulation of these inflammatory molecules after renal ischemia reperfusion (IR). The study was carried out in the laboratory of Department of Pharmacology. Forty-six male Wistar albino rats were divided into five groups as control (n = 6), positive control (n = 4), sham (n = 12), renal IR (n = 12), and renal IR melatonin (n = 12). After 1 h renal pedicle occlusion, the blood samples were taken for the measurement of cytokine levels at second hour of the reperfusion. The rats were sacrificed after 24 h of reperfusion for histopathological evaluation. Melatonin or vehicle was administrated to IR rats. Lipopolysaccharide (LPS) was administered to the positive control group and the blood was taken at fourth hour. Serum TNF-α levels increased significantly in renal IR and LPS groups. Serum IL-6 levels were not different from control except the LPS group. There was no significant correlation between the serum TNF-α levels and the histopathological score after renal IR. Melatonin treatment reversed the increase of serum TNF-α levels and histopathological injury in renal tissue after renal IR. Melatonin may have a protective effect by reducing the serum level of TNF-α in renal IR.

Effects of methoctramine on bladder overactivity in a rat model

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.

Investigating the effect of the poly(ADP-ribose) polymerase inhibitor 5-aminoisoquinolinone and the Na⁺-H⁺ exchanger inhibitor zoniporide on isolated perfused rat hearts during ischemia-reperfusion injury.

The goal of this study was to investigate whether the combination of the Poly(ADP-ribose) polymerase inhibitor 5-aminoisoquinolinone (5-AIQ) and the Na+-H+ exchanger inhibitor zoniporide (ZN) provides increased protection against ischemia-reperfusion (I/R) injury. Rats were separated into 5 groups (n=8): Group 1: Control group, Group 2: I/R, Group 3: 5-AIQ, Group 4: ZN and Group 5: Mix (5-AIQ+ZN). Isolated rat hearts were subjected to 30 min of global ischemia, followed by 120 min of reperfusion using Langendorffs apparatus. In groups 3, 4 and 5, 5-AIO (7.5 μM/L) and ZN (50 nM/L) were added to Tyrode Solution after a stabilization period. The level of lactate dehydrogenase (LDH) was determined in the sample perfusate. Myocardial infarct size was determined using the triphenyltetrazolium chloride method. Heart tissues were stored to determine the malondialdehyde (MDA) content, total oxidant status (TOS) and total antioxidant status (TAS). Compared to the 5-AIQ and ZN groups, there was no notable difference in the LDH, MDA, TOS, TAS and hemodynamic parameters of the 5-AIQ+ZN group, but myocardial infarct size decreased significantly, as determined by volume and weight measurements. These results show that the combined use of Zoniporide and 5-Aminoisoquinolinone provides increased protection against I/R injury by reducing myocardial infarct size.