Impact of Endometrioma Resection on Eutopic Endometrium Metabolite Contents: Noninvasive Evaluation of Endometrium Receptivity.

The aim of this study was to determine whether endometrioma resection alters most commonly defined endometrial metabolites, lactate (Lac), N-acetylaspartate (NAA), creatine 1 (Cr1), creatine 2 (Cr2), and choline (Cho) during the window of implantation. Twenty patients with uni- or bilateral endometrioma and 7 patients having nonendometriotic benign ovarian cyst were included. Midluteal phase magnetic resonance spectroscopy analysis of eutopic endometrium was performed before surgery. Second spectrum of endometrium was obtained 3 to 5 months after laparoscopic endometrioma resection. Pre- and postoperative endometrial peaks of Lac, NAA, Cr, and Cho were measured in units and denominated in parts per million (ppm). Compared to preoperative peak values, significantly decreased NAA, Lac, and Cr1 signals were noted in patients undergoing endometrioma surgery. Nearly 5-fold decline in the NAA signal occurred after endometrioma surgery (1.94 ± 3.24 vs 0.37 ± 0.55). Likewise, 2.5-fold decline in Lac signals was noted after endometrioma resection (2.81 ± 2.64 vs 1.06 ± 1.88). Both uni- and bilateral endometrioma affected endometrium signals the same. The peak intensity of Cho, Cr1, Cr2, NAA, and Lac did not alter significantly after nonendometriotic cyst surgery. Endometrioma surgery straightens endometrial NAA, Lac, and Cr1 peaks, suggesting improvement in endometrial receptivity.

The effects of novokinin, an AT2 agonist, on blood pressure, vascular responses, and levels of ADMA, NADPH oxidase, and Rho kinase in hypertension induced by NOS inhibition and salt.

BACKGROUND/AIM: The effects of AT2 receptor agonist novokinin on blood pressure, eNOS, NADPH oxidase, protein arginine methyltransferases (PRMTs), and Rho kinase in hypertension were investigated. Furthermore, in isolated thoracic aorta rings, contractile and dilator responses were studied. MATERIALS AND METHODS: To develop hypertension, L-NAME was administered intraperitoneally and salt was given with tap water (1%) for 4 weeks. Novokinin was administered intraperitoneally for the last 2 weeks. Blood pressures were measured using the tail-cuff method and enzyme levels by real-time polymerase chain reaction in aortic tissues. RESULTS: Blood pressure increased significantly in hypertensive rats. Novokinin reduced the blood pressure in the hypertensive group. While the contractile responses to increasing doses of angiotensin II were increased, vascular reactivity (Emax) and sensitivity (EC50) to acetylcholine were decreased in hypertensive rats. In novokinin-treated hypertensive groups, the EC50 value decreased and the Emax value for acetylcholine significantly increased. The levels of Rho kinase and PRMT expression increased and the level of eNOS expression decreased in the hypertensive group. In novokinin-treated rats, ADMA, NADPH oxidase, and Rho kinase tended to decreased, but these changes did not reach statistical significance. CONCLUSION: Although further studies are needed to determine its effectiveness, the AT2 agonist novokinin may be a novel agent that is promising in terms of protective effects for the treatment of hypertension.

Oxidative stress and antioxidant parameters in neutropenic patients secondary to chemotherapy.

OBJECTIVE: Neutropenia is a serious adverse event that necessitates dosage reduction in patients receiving chemotherapy. In this study, we evaluated the oxidative stress and antioxidant parameters in neutropenic patients after chemotherapy both during the neutropenic period and after successful treatment of neutropenia with filgrastim. METHODS: We studied paraoxonase (PON1), arylesterase (ARE), malondialdehyde (MDA), high-density lipoprotein (HDL), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) in addition to routine biochemical and hematologic parameters. SPSS 12.0 was used for statistical evaluation of data (SPSS, Chicago, IL, USA). RESULTS: In our study, PON1, HDL, and LDH levels during the period of active neutropenia were statistically significantly higher than these levels were after resolution of neutropenia (P<0.05); MDA and ALP levels were statistically significantly lower during the period of active neutropenia (P<0.05). CONCLUSIONS: Overall, free oxygen radicals (FOR) were increased and antioxidant parameters were decreased with resolution of neutropenia. This is probably due to FOR produced by the increased number of neutrophils rather than tumor burden.

Copeptin Levels in Cerebral Infarction, Intracranial Hemorrhage and Subarachnoid Hemorrhage.

BACKGROUND: To determine copeptin levels in patients with suspected intracranial events and to determine whether copeptin levels could be used in the discrimination of cerebral infarction, intracranial hemorrhage, and subarachnoid hemorrhage in the emergency room. METHODS: Blood samples were obtained from the patients prior to imaging to determine the levels of copeptin. Patients were divided into diagnostic groups after the imaging. One hundred and seventy-six participants, who were enrolled in the study, were as follows: 50 cerebral infarction (CI) patients (M/F: 24/26), 47 intracranial hemorrhage (ICH) patients (M/F: 27/20), 29 subarachnoid hemorrhage (SAH) patients (M/F: 17/12) and 50 healthy controls. Differences and correlations between groups were analyzed. RESULTS: Plasma levels of copeptin in patients with CI, ICH, and SAH were 5.49 ng/dL (IQR 4.73 to 6.96), 4.50 ng/dL (IQR 3.04 to 9.77), and 5.90 ng/dL (IQR 3.11 to 13.26), respectively. It was found to be 2.0 ng/dL (IQR 1.57 to 2.5) in healthy volunteers. There was no significant correlation between copeptin levels and Intracerebral Hemorrhage Score (ICHS) (r = 0.231, p = 0.118). However, significant positive correlation was found between copeptin levels with the National Institutes of Health Stroke Scale (NIHSS) (r = 0.365, p = 0.009) and the BotterelHunt and Hess Scale (BHHS) (r = 0.590, p = 0.001). The copeptin levels of 41 (32.5%) patients who died were found to be significantly higher than those 85 (67.5%) patients who were discharged (p < 0.001). CONCLUSIONS: Copeptin levels in patients with CI, ICH, and SAH are significantly higher than healthy volunteers, but the plasma level of copeptin is not decisive in the discrimination of CI, ICH, and SAH.

Metabolic syndrome does not impair the response to alfuzosin treatment in men with lower urinary tract symptoms: a double-blind, randomized, placebo-controlled study.

OBJECTIVE: This study is a placebo-controlled comparison of the response to alfuzosin treatment for lower urinary tract symptoms (LUTS) in patients with and without metabolic syndrome (MetS). MATERIAL AND METHODS: A total of 80 men with LUTS were included in the study. Patients had a maximum flow rate of <15 mL/sec, prostate volume of >20 mL, and International Prostate Symptom Score (IPSS) of >8. All eligible men (n=68) for evaluation were initially divided into two groups as MetS (n=34) and non-MetS (n=34) groups. Patients were further randomized to receive alfuzosin (10 mg/day) or placebo (n=17/group; a total of four groups). The outcome was measured at 12(th) week according to the changes from baseline in IPSS, quality of life (QoL) scores, maximum flow rate (Qmax), and postmictional residue. RESULTS: Alfuzosin significantly improved LUTS in men with and without MetS compared with patients receiving placebo (p<0.05). Mean IPSS scores in treatment groups decreased significantly, whereas patients receiving placebo had no statistically significant difference (p>0.05). Similarly, alfuzosin treatment resulted in a significant increase in Qmax in patients with LUTS/benign prostatic enlargement when compared with patients in placebo group (p<0.05). Mean QoL scores measured by IPSS-QoL and QoL questionnaires also improved significantly in patients receiving alfuzosin for 3 months regardless of the presence of MetS (p<0.05). CONCLUSION: Our results revealed that the presence of MetS in patients with LUTS did not impair the response to alfuzosin treatment.

Evaluation of the efficacy of sodium valproate in convulsive status epilepticus following to ischemic stroke.

OBJECTIVE: Convulsive status epilepticus (CSE) is very rarely observed after ischaemic stroke. Sodium valproate (SV) is one of the agents used in the treatment of CSE, but its role still controversial, and its degree of efficacy in treating CSE that develops following stroke is unclear. METHOD: We evaluated 19 patients who were treated with intravenous (IV) SV (20 mg/kg, 2 mg/kg/h-12h) after diazepam. Patients' modified Rankin scores (mRS), SE types, and changes in biochemical parameters after treatment were assessed. RESULTS: CSE was successfully treated in 12 (63.15%) patients. Side effects such as hypotension and allergic reactions were observed in two patients. Refractory SE development was observed in 5 (29.4%) patients with high mRS (˃ 3). No significant deterioration in patients' laboratory evaluations, conducted before and after status, was observed. CONCLUSION: SV may be safe and effective in the treatment of CSE observed after ischaemic stroke, especially in patients with low mRS.

2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced hypertension: the beneficial effects of melatonin.

OBJECTIVE: The purpose of the present study was to evaluate the effects of melatonin on biochemical and cardiovascular changes resulting from exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a polychlorinated dibenzo-para-dioxin. METHODS: A total of 24 Sprague-Dawley rats were divided equally into the following four groups: (1) control group was administered with 0.5 mL corn oil by gavage and 0.5 cc vehicle of melatonin (proportionally nine parts physiological serum + one part ethyl alcohol) intraperitoneally for 4 weeks, (2) the melatonin group was given 5 mg/kg/day melatonin intraperitoneally for 4 weeks, (3) the TCDD group was given 500 ng/kg/day TCDD by gavage for 4 weeks and (4) the TCDD + melatonin group was given TCDD (500 ng/kg/day) by gavage and melatonin (5 mg/kg/day) intraperitoneally simultaneously for 4 weeks. Systolic blood pressure was evaluated by the tail-cuff method. Vascular responses to phenylephrine and acetylcholine were evaluated in the isolated thoracic aortas. RESULTS: TCDD not only augmented the systolic blood pressure but also increased the contractile responses to phenylephrine in aorta. Melatonin reversed the blood pressure augmented by TCDD and decreased the contractile responses to phenylephrine in aorta. TCDD induced an increase in the malondialdehyde levels in kidney tissue and melatonin did not change it. Therefore, TCDD caused a decrease in glutathione levels in kidney tissues and melatonin reversed it. CONCLUSION: Present data demonstrated that TCDD may lead to an increase in blood pressure via increased renal oxidative stress and vascular reactivity. However, melatonin might ameliorate the blood pressure disturbed by TCDD in part by decreasing the oxidant activity induced by TCDD.

The effect of caffeic acid phenethyl ester on isoproterenol-induced myocardial injury in hypertensive rats.

OBJECTIVE: The aim of this study is to investigate the effects of caffeic acid phenethyl ester (CAPE) on isoproterenol (ISO)-induced myocardial injury in hypertensive rats. METHODS: Rats were divided into 4 groups (n=29): Control group (n=8), L-NNA (NG-Nitro-L-arginine) group (n=8), L-NNA+ISO (L-NNA+isoproterenol) group (n=7) and L-NNA+ISO+CAPE (L-NNA+ISO + caffeic acid phenethyl ester) group (n=6). ISO (150 mg/kg/day) was given intraperitoneally (i.p.) once a day for 2 consecutive days (at the 12th and 13th days of L-NNA treatment). NG-Nitro-L-arginine (L-NNA) was given orally (25 mg/kg/day) in drinking water for 14 days. CAPE (10 µmol/kg/day) was given (i.p.) for 7 days after the first week. Systolic blood pressure (SBP) was evaluated by the tail-cuff method and biochemical analysis were performed using an autoanalyzer and a spectrophotometer. RESULTS: SBP in all L-NNA-treated groups was found to be increased at seventh day. AST and LDH levels in LNNA+ISO group were significantly increased compared to control (AST: 125±5 vs. 105±2; LDH: 861±154 vs. 571±46 U/L respectively) (p<0.05). Also, ISO caused to extensive necrosis and mononuclear cell infiltration in hypertensive rat myocardium. CAPE application reversed the enhanced AST and LDH levels as well as the extensive necrosis and the mononuclear cell infiltration in LNNA+ISO+CAPE group compared LNNA+ISO. CONCLUSION: According to our findings, it might be suggested that CAPE may be a favorable agent to protect the hypertensive myocardium from the injury induced by isoproterenol via mechanisms such as the induction of the antioxidant enzymes and the inhibition of lipid peroxidation.

Irisin: a potentially candidate marker for myocardial infarction.

Myocardial infarction (MI) causes energy depletion through imbalance between coronary blood supply and myocardial demand. Irisin produced by the heart reduces ATP production by increasing heat generation. Energy depletion affects irisin concentration in circulation and cardiac tissues, suggesting an association with MI. We examined: (1) irisin expression immunohistochemically in rat heart, skeletal muscle, kidney and liver in isoproterenol (ISO)-induced MI, and (2) serum irisin concentration by ELISA. Rats were randomly allocated into 6 groups (n=6), (i) control, (ii) ISO (1h), (iii) ISO (2h), (iv) ISO (4h), (v) ISO (6h), and (vi) ISO (24h), 200mg ISO in each case. Rats were decapitated and the blood and tissues collected for irisin analysis. Blood was centrifuged at 1792 g for 5 min. Tissues were washed with saline and fixed in 10% formalin for histology. Serum irisin levels gradually decreased from 1h to 24h in MI rats compared with controls, the minimum being at 2h, increasing again after 6h. Cardiac muscle cells, glomerular, peritubular renal cortical interstitial cells, hepatocytes and liver sinusoidal cells and perimysium, endomysium and nucleoi of skeletal muscle were irisin positive, but its synthesis decreased 1-4h after MI. At all time-points, irisin increased near myocardial connective tissue, with production in skeletal muscle, liver and kidney recovering after 6h, although slower than controls. Unique insight into the pathogenesis of MI is shown, and the gradually decrease of serum irisin might be a diagnostic marker for MI.

Protective effects of L-carnitine, N-acetylcysteine and genistein in an experimental model of liver fibrosis.

AIM: Liver fibrosis is a reversible wound-healing response that occurs following liver injury. In this study, we aimed to investigate the possible protective effects of L-carnitine, N-acetylcysteine and genistein in liver fibrosis induced by carbon tetrachloride (CCl4). In addition, the effects of these agents were compared in the same study. METHODS: In this study, rats were randomly allocated into 8 groups, consisting of 10 rats each, as follows: a control group, CCl4, L-carnitine, N-acetylcysteine, genistein, CCl4 and L-carnitine, CCl4 and N-acetylcysteine, and CCl4 and genistein. At the end of 6 weeks, blood and liver tissue specimens were collected. Alanine aminotransferase (ALT); aspartate aminotransferase (AST); complete blood count, tumor necrosis factor-α (TNF-α); platelet-derived growth factor-BB (PDGF-BB); interleukin-6 (IL-6); liver glutathione level; oxidant/antioxidant status; scores of hepatic steatosis, necrosis, inflammation, and fibrosis; and the expression of α-smooth muscle actin were studied. RESULTS: Although the ALT and AST values in the group administered CCl4 were significantly higher than in all the other groups (P<0.05), there was no significant difference between the control group and the groups administered CCl4 combined with L-carnitine, N-acetylcysteine and genistein (P>0.05). There were significant differences in the levels of TNF-α, PDGF-BB and IL-6 (P<0.05) between the CCl4 group and the groups with L-carnitine, N-acetylcysteine and genistein added to CCl4. N-acetylcysteine and genistein had positive effects on the oxidant/antioxidant status and on liver necrosis and fibrosis scores. CONCLUSIONS: In our study, L-carnitine, N-acetylcysteine and genistein showed significant protective effects in liver fibrosis induced by CCl4.

The investigation of serum vaspin level in atherosclerotic coronary artery disease.

BACKGROUND: It was speculated that fatty tissue originated adipocytokines may play role in pathogenesis of atherosclerosis. These adipocytokines may alter vascular homeostasis by effecting endothelial cells, arterial smooth muscle cells and macrophages. Vaspin is a newly described member of adipocytokines family. We aimed to investigate whether plasma vaspin level has any predictive value in coronary artery disease (CAD). METHODS: Forty patients who have at least single vessel ≥ 70 % stenosis demostrated angiographically and 40 subjects with normal coronary anatomy were included to the study. The vaspin levels were measured from serum that is obtained by centrifigation of blood and stored at -20 (o)C by ELISA method. The length, weight and body mass index of patients were measured. Biochemical parameters including total cholesterol, low density lipoprotein, high density lipoprotein, creatinine, sodium, potassium, hemoglobine, uric acid and fasting glucose were also measured. RESULTS: Biochemical markers levels were similar in both groups. Serum vaspin levels were significantly lower in CAD patients than control group (respectively; 256 ± 219 pg/ml vs. 472 ( 564 pg/ml, P < 0.02). Beside this serum vaspin level was lower in control group with high systolic blood pressure. CONCLUSION: Serum vaspin levels were found significantly lower in patients with CAD than age-matched subjects with normal coronary anatomy. Vaspin may be used as a predictor of CAD. KEYWORDS: Coronary artery disease; Vaspin; Adipokine.

Ceftriaxone ameliorates cyclosporine A-induced oxidative nephrotoxicity in rat.

A growing body of evidence now suggested that cyclosporine A (CycA)-induced nephrotoxicity is a crucial clinical problem and oxidative stress is importantly responsible for its toxicity. Ceftriaxone induced antioxidant effect in brain and neuronal tissues against oxidative damage although its antioxidant potential effect on kidney has not been clarified. The aim of this study was to evaluate whether ceftriaxone protects CycA-induced oxidative stress kidney injury in rats. Twenty-four rats were equally divided into four groups. First group was used as control. Ceftriaxone (200 mg/kg) and CycA (15 mg/kg) were administrated to second and third groups for 10 days, respectively. The ceftriaxone and CycA combination was given to rats constituting the fourth group for 10 days. Lipid peroxidation (LP), urea nitrogen and lactate dehydrogenase (LDH) levels were higher in CycA group than in control and ceftriaxone groups although LP, urea nitrogen and LDH levels were lower in ceftriaxone + CycA group than in control and ceftriaxone groups. Glutathione peroxidase and catalase activities were lower in CycA group than in control whereas their activities were increased in control and ceftriaxone groups. Superoxide dismutase activity did not change by the treatments. Ceftriaxone administration recovered also CycA-induced atrophy, vacuolization and exfoliations of tubular epithelium and glomerular collapse in histopathological evaluation of kidney. In conclusion, we observed that ceftriaxone is beneficial on CycA-induced oxidative stress in kidney of rats by modulating oxidative and antioxidant system.

Salt and nitric oxide inhibition induced hypertension: the role of prostacycline and 8-isoprostane.

Renal prostacycline (PGI(2)) and oxidative stress are known to be important factors that effect the natriurezis and diuresis. 8-iso prostaglandin F(2)α± (8-isoprostane), a member of F(2)-isoprostanes, is formed from the nonenzymatic reaction of arachidonic acid and oxygen radicals in vivo and in vitro, and also it is a marker of oxidative stress in vivo. The aim of this study is to determine the role of renal PGI(2) and 8-isoprostane in a salt and nitric oxide (NO) inhibition-induced hypertension model. Rats were distributed equally among four groups (n = 6 per group). Control rats were given normal salt diet (0.32%); high-salt (HS) rats were given high salt diet (3.2%); NG-nitro-L-arginine (L-NNA) rats were given normal salt diet and 25 mg/kg L-NNA; HS+L-NNA rats were given high salt diet and 25 mg/kg L-NNA. Rats were placed in individual metabolic cages for 17 days. Systolic blood pressure (SBP) was measured at days initial, 7th and 14th .Urinary 8-isoprostane and PGI(2) levels were analyzed. Salt- loading alone did not change SBP values. The average SBP in L-NNA and HS+L-NNA groups were shown to significantly enhance compared to initial and day 7th in the same groups, respectively. The levels of 8-isoprostane in the HS+L-NNA group was significantly enhanced compared to the other groups. L-NNA or HS diet alone did not change the levels of 8-isoprostane compared to the control group. L-NNA alone did not change PGI(2) levels in urine compared to the control. PGI(2) levels in the HS, and the HS+L-NNA group was significantly higher compared to the control group. This study concluded that NOS inhibition plus salt-loading induced oxidative stress and increased renal PGI(2). Also, it is suggested that augmented oxidative stress may aggravate the hypertension. But the renal synthesis of PGI(2) is increased in order to augment the diuresis and natriuresis without the effect of blood pressure (BP).

Salt and nitric oxide synthase inhibition-induced hypertension: kidney dysfunction and brain anti-oxidant capacity.

The specific aim of this study was to examine the effects of salt-loading on kidney function and brain antioxidant capacity. Wistar rats were divided into four groups: Control rats were given normal drinking water and no drug treatment for 2 weeks. LNNA group: rats were given normal drinking water and the nitric oxide (NO) inhibitor NG-nitro-L-arginine (L-NNA), 3 mg/kg/day. LNNA + Salt group: rats were given drinking water containing salt 2% and 3 mg/kg L-NNA. Salt group: rats were given drinking water containing salt 2% and no drug treatment. Basal blood pressure and the levels of serum BUN, creatinine, uric acid, cortisol, electrolyte, serum antioxidant capacity, and oxidative stress were measured. NO, superoxide dismutase (SOD), and catalase (CAT) levels were measured in the hypothalamus, brainstem, and cerebellum. Salt overload increased the blood pressure of the LNNA + Salt group. Salt-loading enhanced BUN, creatinine, sodium retention. High salt produced an increase in uric acid levels and a decrease in cortisol levels in serum. Additionally, the oxidative stress index in serum increased in the LNNA + Salt group. Salt-loading enhanced brain NO levels, but not SOD and CAT activity. L-NNA increased brain SOD activity, but not CAT and NO levels. In conclusion, salt-loading causes hypertension, kidney dysfunction, and enhances oxidative stress in salt-sensitive rats.

Effects of caffeic acid phenethyl ester on isoproterenol-induced myocardial infarction in rats.

OBJECTIVE: Caffeic acid phenethyl ester (CAPE) is a natural product with potent anti-inflammatory, antitumor and antioxidant activities and attenuates inflammation and lipid peroxidation induced by ischemia-reperfusion injury. The purpose of the present study was to investigate the effects of CAPE on isoproterenol (ISO) -induced myocardial infarction. METHODS: A randomized controlled experimental design was used in this study. Rats were divided into four groups and treated with saline, CAPE, ISO and ISO+CAPE. Rats were treated with CAPE (10 micromol kg/day i.p.) or saline starting 3 days before injecting ISO (150 mg /kg s.c., 24 hours). Seven days later, rats were sacrificed and the hearts were excised for biochemical analyses and microscopic examination. One-way ANOVA test with post hoc multiple comparisons using LSD method were used for statistical analysis of the data. RESULTS: The administration of ISO alone resulted in higher myeloperoxidase (MPO) activity, lipid peroxidation, superoxide dismutase (SOD) and catalase (CAT) than in the control. The enzyme activities did not change in rat given CAPE alone. CAPE treatment prevented the increase in MPO activity and malondialdehyde, but did not affect the activities SOD and CAT enzymes. CONCLUSION: In light of these results, we conclude that CAPE prevents MPO-and lipid peroxidation-mediated myocardial injury via inhibition of neutrophil's MPO activity.

Protective effect of caffeic acid phenethyl ester on cyclosporine A-induced nephrotoxicity in rats.

INTRODUCTION: Cyclosporine A, an immunosuppressive agent, is widely used after organ transplantation such as the liver and kidney. However, its widespread use is restricted because it has serious toxic effects on the kidney. Caffeic acid phenethyl ester (CAPE) is a natural product with potent anti-inflammatory, antitumor, and antioxidant activities, and it attenuates inflammation and lipid peroxidation induced by ischemia-reperfusion injury. The purpose of the present study was to investigate the effects of CAPE on cyclosporine A (CsA)-induced nephrotoxicity. MATERIAL AND METHODS: Rats were divided into four groups and treated with saline, CAPE, CsA, and CsA + CAPE. Control rats were given saline; the CAPE group was given CAPE (10 micromol/kg/day) for 11 days intraperitoneally; the CsA group was given CsA (15 mg/kg/day) for 10 days subcutaneously; and the CsA+CAPE group was given CAPE for 11 days, and rats were s.c. injected with CsA in 0.5 ml of saline once a day for 10 days at the same time. RESULTS: The administration of CsA alone resulted in higher myeloperoxidase (MPO) activity, lipid peroxidation, superoxide dismutase (SOD), and catalase (CAT) than in the control. The enzyme activities except CAT in rats treated with CAPE alone were not changed. CAPE treatment prevented the increase in malondialdehyde (MDA) and increased CAT activity more, but did not affect the activities of MPO and SOD enzymes. DISCUSSION: CsA causes renal injury and CAPE prevents CAT- and lipid peroxidation-mediated nephrotoxicity via inhibition of oxidative process.

[Clonidine prevents development of hypertension in N (omega)-nitro-L-arginine-treated rats]. / Klonidin N (omega)-nitro-L-arjinin aracili hipertansiyon gelisimini önler.

OBJECTIVE: Although, there are some evidences on the contribution of increased sympathoadrenergic activity on long-term nitric oxide synthase (NOS) inhibition induced hypertension, the contribution of sympathetic activity to the development of this model of hypertension are not sufficiently studied. The aim of the present study is to investigate the effects of clonidine on blood pressure and vascular alpha-adrenergic receptors in the long-term N (omega)-nitro-L-arginine (L-NNA) treated rats. METHODS: Sixty two Wistar rats were randomly divided into 8 groups. All groups were administrated L-NNA and/or clonidine in two different concentrations for ten days. L-NNA was administrated in concentrations of 15 and 45 mg/100ml to L-NNA15 and L-NNA45 groups, respectively. Clonidine was also administrated in concentrations of 150 and 225 microg/100ml to KLO150 and KLO225 groups, respectively. Blood pressure and heart rates were measured with tail-cuff method and plasma NOx levels with spectrophotometer. The a-adrenoreceptors responses were evaluated in thoracic aorta rings in "in vitro" conditions. RESULTS: Clonidine prevented the L-NNA induced hypertension dose-dependently, but did not effect the heart rates decreased by L-NNA. The heart rates and blood pressure of normotensive rats were not changed by clonidine alone. Plasma NOx levels increased in L-NNA15 group (0.62+/-0.11 micromol/L, p=0.003) but did not change in other groups. The sensitivity of aorta to phenylephrine (-7.33+/-0.11 micromol/L, p=0.001) and clonidine (-7.60+/-0.27 micromol/L, p=0.003) in L-NNA45 group and phenylephrine (-6.94+/-0.13 micromol/L, p=0.002) in L-NNA15 group increased. The sensitivity of aorta to phenylephrine (7.93+/-0.16 micromol/L, p=0.001) in KLO225 group and to clonidine (-7.20+/-0.10 micromol/L, p=0.009) in KLO150 group increased. CONCLUSION: This study supports the idea suggesting that symphathetic nervous system activation is partly responsible for the development of the long-term NOS inhibition induced hypertension. In conclusion, it was shown for the first time that clonidine prevents the development of long-term NOS inhibition induced hypertension dose-dependently.

Melatonin attenuates renal ischemia-reperfusion injury in nitric oxide synthase inhibited rats.

Recent studies show that melatonin reduces the blood pressure (BP) and ischemia/reperfusion (I/R)-induced damage. This study was designed to investigate the effects of melatonin on the renal I/R injury in rats given the nitric oxide synthase (NOS) inhibitor, N(omega)-nitro-L-arginine methyl ester (L-NAME). After right nephrectomy, I/R was induced by occlusion of the left renal vessels for 60 min, followed by 24h reperfusion. The administration of melatonin significantly attenuated BP in NOS-inhibited hypertensive rats. Malondialdehyde (MDA) levels, a stable metabolite of the free-radical-mediated lipid peroxidation cascade, were found to be significantly higher in the I/R group (3.48+/-0.2mg/l serum) than in the control group (2.69+/-0.2mg/l serum). L-NAME (40 mgkg(-1) for 15 days)+I/R significantly increased the MDA levels compared to I/R alone. Melatonin administration to L-NAME rats significantly reduced the MDA values resulting from I/R. We also demonstrated that I/R, and especially L-NAME+I/R, lead to structural changes in the kidney and that melatonin attenuates these changes. These results suggest that melatonin reduces BP and I/R injury in NOS inhibited rats by L-NAME.