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

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.

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 statins in an indomethacin-induced gastric injury model in rats.

BACKGROUND/AIMS: Statins have additional pleiotropic effects beyond their lipid-lowering effects. In this study, the effects of statins were evaluated in an indomethacin-induced gastric injury model in rats. MATERIALS AND METHODS: Animals were divided into eight groups. Distilled water (control group), omeprazole (30 mg/kg), atorvastatin (20 and 40 mg/kg), simvastatin (20 and 40 mg/kg), and rosuvastatin (20 and 40 mg/kg) were given orally (gavage). Thirty minutes later, indomethacin (25 mg/kg) was administered orally to all groups. Six hours later, the animals were sacrificed by decapitation. The mean ulcer indexes for each group were calculated, and the stomachs were evaluated histopathologically. RESULTS: The ulcer indexes were as follows: control 1.72 ± 0.16, omeprazole 0 ± 0.00, and atorvastatin, simvastatin and rosuvastatin (at 20 and 40 mg/kg doses, respectively) 4.28 ± 0.39, 4.99 ± 0.96, 1.72 ± 0.73, 1.90 ± 0.48, 1.85 ± 0.26, and 1.67 ± 0.18. Atorvastatin significantly increased the indomethacin-induced ulcer index at both doses and the erosion score at 40 mg/kg dose. Although the 20 mg/kg dose of simvastatin inhibited mononuclear leukocyte infiltration, the 40 mg/kg dose induced hyperemia. Rosuvastatin did not decrease mononuclear leukocyte or neutrophil infiltrations at 20 mg/kg dose, and only neutrophil infiltration at the 40 mg/kg dose. CONCLUSIONS: In patients with gastric discomfort, statins must be used carefully. If statin therapy is needed, we recommend to avoid using atorvastatin and to use the other statins only in the minimum effective dose.

Effects of 3-aminobenzamide on unilateral testicular ischemia-reperfusion injury: what is the role of PARP inhibition?

The therapeutic effects of poly(adenosine diphosphate-ribose) polymerase inhibition by 3-aminobenzamide (3-AB) were investigated in testicular ischemia-reperfusion (I/R) injury, using sperm analysis and histopathological and biochemical examinations, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and reduced glutathione (GSH) levels. Male rats were divided into 3 groups: sham (n = 12), I/R (n = 12), and I/R with 3-AB (I/R-3-AB) (n = 12). The left testicular artery was occluded for 1 h, followed by 24 h (for biochemical and histopathological examinations) and 30 days (for sperm analysis) of reperfusion. 3-AB treatment intraperitoneally 10 min prior to and 1 h after reperfusion increased the I/R-induced decrease in sperm motility in both testes and reduced the increased abnormal sperm rates in the ipsilateral testis. However, 3-AB treatment failed to prevent the I/R-induced decrease in sperm concentration in both testes. SOD and CAT activities did not change in any group. GSH-Px activity and GSH levels were increased by I/R. 3-AB treatment reversed the I/R-induced increase in GSH-Px activity, similar to the level in sham rats, but did not alter GSH levels. 3-AB treatment significantly increased the I/R-induced decrease in histopathologic score. In conclusion, 3-AB treatment has potential biochemical and histopathological benefits beyond improving sperm quality and may have the potential to decrease damage from testicular torsion.

Effects of increasing ratio of progesterone in estrogen/progesterone combination on total oxidant/antioxidant status in rat uterus and plasma.

PURPOSE: The relationship between increasing ratio of progesterone in estrogen/progesterone combination and oxidative stress (OS) was investigated. METHODS: Thirty non-pregnant Wistar Albino female rats were divided into five groups and bilaterally ovariectomized (Ovx) except sham group. GROUPS: Sham + 0.3 cc seaseme oil, Ovx + 0.3 cc seaseme oil, Ovx + estradiol propionate (E2) (1 µg/kg), Ovx + E2 + medroxyprogesterone acetate (MPA) 1 mg/kg, Ovx + E2 + MPA 20 mg/kg. Hormones were applied for three consecutive days after 28 days of ovariectomy. Their uteri and blood samples were collected and nitric oxide (NO), malondialdehyde (MDA), total oxidative status (TOS) and total antioxidant capacity (TAC) levels were determined. RESULTS: E2 + MPA1 treatment decreased NO, MDA and TOS levels and increased TAC levels in uterus. Plasma NO levels elevated in all groups and MDA production increased due to E2 treatment when compared to ovariectomy. E2 + MPA20 treatment increased TOS levels, while TAC levels decreased when compared to ovariectomy in plasma. CONCLUSIONS: Using E2 plus low dose progesterone may prevent pathologies resourced of OS.

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.

Lycopene, an antioxidant carotenoid, attenuates testicular injury caused by ischemia/reperfusion in rats.

Testicular torsion is a common syndrome that could lead to infertility. We investigated the therapeutic effects of lycopene, an antioxidant caretenoid, on testicular ischemia/reperfusion (IR) injury that resembles testicular torsion. Male Wistar albino rats were divided into three groups: sham (n = 6), IR (n = 18), and ischemia/reperfusion with lycopene (IRL, n = 18). Left testicular artery and vein was occluded for 1 h, followed by reperfusion of 3 h, 24 h or 30 days in IR and IRL animals. Either corn oil (vehicle) or lycopene (4 mg/kg) was administrated once daily by gavage to IR or IRL animals, respectively, 5 min after ischemia. Sham-operated animals were treated with vehicle by gavage 5 min after the operation. IR decreased sperm motility and concentration in both ipsilateral and contralateral testes and increased abnormal sperm rate in ipsilateral testis after 30 days of reperfusion. Treatment with lycopene increased the motility in bilateral testes and decreased the rate of abnormal sperm in ipsilateral testis to the sham level, but did not increase sperm concentration in bilateral testes. IR increased the activities of catalase and glutathione peroxidase and the level of reduced glutathione by 24 h of reperfusion, but malondialdehyde remained unchanged. Lycopene treatment restored the enzyme activities but not the reduced glutathione level. Lycopene treatment also ameliorated the IR-induced tissue damage in bilateral testes. In conclusion, the therapeutic antioxidant effect of lycopene on germ cells could serve as a promising intervention to oxidative stress-associated infertility problems, such as testicular torsion.

The contribution of nitric oxide on the relaxation effects of diethylstilbestrol.

OBJECTIVE: To evaluate the contribution of nitric oxide NO on the relaxation effects of diethylstilbestrol on rat uterus. METHODS: Uterine rings from 8 nonpregnant Wistar Albino rats 300-350 g in the pro-estrous phase were suspended in an organ bath and electrical field stimulation applied for recording isometric tension. The influence of NO on contractile responses of rat uterine rings was investigated. The effects of NO precursor L-arginine (10(-7) - 10(-4)M) concentration and NO synthase inhibitor L-nitro-arginine-methyl ester (10(-7) - 10(-4)M) concentration and a combination of them on contractile responses were studied in the presence and absence of diethylstilbestrol (2 x 10(-4)M) concentration. The study was carried out at the Department of Pharmacology Laboratory, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. RESULTS: Totally, 30 samples were investigated n=6 for each group, 5 groups. Diethylstilbestrol inhibited contractile responses 64.2+/- 4.5% n=6, p<0.05. Contractile responses decreased in the presence of L-arginine n=6, p<0.05 and this inhibition was abolished in the presence of L-nitro-arginine-methyl ester n=6, p<0.05. The inhibition on contractile responses to diethylstilbestrol was potentiated in the presence of L-arginine under similar conditions n=6, p<0.05. The contractile responses to electrical field stimulation in the presence of diethylstilbestrol were not affected by L-nitro-arginine-methyl ester n=6, p>0.05. CONCLUSION: These data provide evidence that NO may potentiate the inhibitory effects of diethylstilbestrol by different mechanisms on the electrically induced contractions of the non-pregnant rat uterus.

Antioxidant enzyme activities, lipid peroxidation, and total antioxidant status in children with Henoch-Schönlein purpura.

The aim of this study was to assess the role of oxidative stress in the pathogenesis of Henoch-Schönlein purpura (HSP) vasculitis. The activities of catalase (CAT), arylesterase (ARYL), and paraoxonase (PON) as antioxidant enzymes and serum malondialdehyde (MDA) level as an indicator of lipid peroxidation, together with total antioxidant status (TAS), were measured in 29 children with HSP (mean age 9.3 +/- 2.7 years), both at the onset of the disease and at the remission period and in matched controls. Active-stage HSP had significantly higher MDA level (15.5 +/- 7.3 vs 7.8 +/- 3.9 nmol/l, respectively, P < 0.001) and lower TAS (524 +/- 122 vs 699 +/- 122 mumol Trolox Equiv/l, P < 0.001), PON (97 +/- 47 vs 136 +/- 95 U/l, P = 0.042), ARYL (158 +/- 39 vs 212 +/- 52 U/l, P < 0.001), and CAT (50 +/- 27 vs 69 +/- 20 U/l, P = 0.002) activities compared with the control subjects. Although CAT (P > 0.05) and PON (P > 0.05) activities were found to be similar between active and remission stages of HSP, the active stage of the disease had significantly lower ARYL (P = 0.011) and TAS (P = 0.006) and higher MDA (P < 0.001) values compared with remission period. Significant positive correlations were found between CAT and MDA (r = 0.433, P = 0.019) and between CAT and C-reactive protein (r = 0.386, P = 0.035) in the active stage of HSP. No significant differences were detected in oxidant/antioxidant parameters between patients with or without renal, gastrointestinal, or joint involvement (P > 0.05). Increased oxidative stress and lipid peroxidation may play important roles in the pathogenesis of HSP vasculitis. Antioxidant therapeutic interventions in long-lasting vasculitis and risk of atherosclerosis secondary to increased oxidant stress remain to be investigated.

Neutrophil activation, protein oxidation and ceruloplasmin levels in children with Henoch-Schönlein purpura.

The aim of this study was to investigate the role of neutrophil activation, protein oxidation and ceruloplasmin (CLP) in the pathogenesis of Henoch-Schönlein purpura (HSP), which has not been investigated previously. Serum activities of myeloperoxidase (MPO) and arylesterase (ARYL) and levels of free thiol groups, CLP and total oxidant status (TOS) were measured in 29 children with HSP at the onset of the disease and during remission in comparison with 30 healthy subjects. Patients at active stage had significantly higher MPO activity (391+/-277 vs. 155+/-154 U/l, P<0.001), higher CLP (832+/-120 vs. 682+/-114 mg/dl, P<0.001) and TOS values (20.7+/-11.8 vs. 7.5+/-2.8 micromol H2O2/l, P<0.001) than the controls, respectively. Patients had significantly lower ARYL activity (158x10(3)+/-39x10(3) vs. 187x10(3)+/-46x10(3) U/l, P<0.001) and lower free thiol levels (234+/-48 vs. 279+/-26 micromol/l, P<0.001) than the controls, respectively. Significantly positive correlations were found between TOS and MPO (r=0.437, P=0.018) and TOS and CLP (r=0.409, P=0.028) at disease onset, whereas a negative correlation was found between MPO and thiol (r=-0.597, P=0.001) during remission. In conclusion, protein oxidation and neutrophil activation may play important roles in the pathogenesis of HSP. Further research is required to understand the potential linkage between oxidant stress and complications and to develop therapeutic strategies in HSP.

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.