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Öğe Aqueous humor adrenomedullin levels differ in patients with different types of glaucoma(Springer Japan Kk, 2002) Evereklioglu, C; Doganay, S; Er, H; Yurekli, MPurpose: Adrenomedullin is a multifunctional 52 amino acid large peptide. Recent studies have reported that it is expressed in the iris-ciliary body in the eye and that it decreases intraocular pressure (IOP) by increasing outflow facility via specific adrenomedullin receptors, suggesting a role for this peptide in controlling IOP. In the present study, we aimed to explore clinically the possible involvement of adrenomedullin in the pathophysiology of glaucoma. Methods: Reverse-phase high-performance liquid chromatography was used to determine the aqueous humor adrenomedullin levels in 41 patients (41 eyes) undergoing elective surgery for a variety of ocular diseases in the Research Hospital of Inonu University Medical Faculty between 1999 and 2000. The ocular diseases of the patients included primary open-angle glaucoma (POAG, n = 16), neovascular glaucoma (NG, n = 11). and cataract (n = 14). The study was an open trial with purposive sampling. Aqueous humor samples were taken by paracentesis. Mann-Whitney U-test was used in the statistical analysis and P < .05 was considered as significant. Results were expressed as mean +/- SE. Results: The mean age and sex distribution between groups were comparable. Mean adrenomedullin levels in patients with POAG (22.3 +/- 0.6 pmol/L) were significantly higher than those in patients with NG (5.6 +/- 0.2. pmol/L; P < .001) and cataract (11.9 +/- 0.5, pmol/L., P < .001). On the other hand, the mean aqueous humor adrenomedullin levels in patients with NG were significantly (P < .001) lower than those in cataract patients. Conclusions: This first clinical in vivo study on aqueous humor adrenomedullin levels showed that this peptide may be involved in the pathophysiology of glaucoma. Increased aqueous humor adrenomedullin levels in patients with POAG may indicate a compensatory defense response against increased IOP to slow the formation and progression of a vicious cycle, On the other hand, there may be deficient production of the peptide in patients with NG, or adrenomedullin-producing cells may be lost because of very high IOP during the course of the disease. The control of adrenomedullin levels in the eve might be a target that could be considered in the therapeutic strategies for glaucoma. Further studies in this respect are needed. (C) 2002 Japanese Ophthalmological Society.Öğe Cerebrospinal fluid adrenomedullin levels in patients with pre-eclampsia(Blackwell Munksgaard, 2003) Celik, O; Hascalik, S; Yurekli, M; Turkoz, Y[Abstract Not Available]Öğe Decreased adrenomedullin and total nitrite levels in breast milk of preeclamptic women(Pergamon-Elsevier Science Ltd, 2004) Cekmen, MB; Balat, A; Balat, O; Aksoy, F; Yurekli, M; Erbagci, AB; Sahinoz, SObjective: To observe the adrenomedullin (AM) and total nitrite levels in the milk of preeclamptic and normal pregnant women. Design and methods: Fifteen women with preeclampsia and 15 normal pregnant women were included in the study. Total nitrite was quantitated by Griess reaction, while AM was measured by HPLC. Results: The levels of AM and total nitrite in colostrum and 30th-day breast milk were decreased in preeclamptics. Total. nitrite levels (mumol/l) were 56.09 +/- 11.18 vs. 82.20 +/- 12.01, P < 0.05, in colostrum of preeclamptics and controls, respectively. The level of total nitrite was 37.75 +/- 12.10 vs. 53.28 +/- 10.25, P < 0.05, in 30th-day milk of same patients. AM levels (pg/ml) were 11.18 +/- 1.11 vs. 16.59 +/- 1.24, P < 0.0001, in colostrum of preeclamptics and controls, respectively. In 30th-day milk of same patients, AM levels were 8.41 +/- 1.39 vs. 12.18 +/- 1.48, P < 0.005, respectively. Conclusion: This report shows for the first time that human milk has decreased levels of AM and total nitrite in preeclampsia. (C) 2003 The Canadian Society of Clinical Chemists. All rights reserved.Öğe The effect of adrenomedullin (AdM) and cold exposure on tyrosine hydroxylase (TH) enzyme activity and blood pressure(Federation Amer Soc Exp Biol, 2001) Yurekli, M; Yuksel, SB[Abstract Not Available]Öğe The effect of adrenomedullin (ADM) on tyrosine hydroxylase (TH) enzyme activity and blood pressure in cold exposed rats(Japan Endocrine Soc, 2003) Yuksel, S; Yurekli, MIt is known that, under stress conditions the hypothalamo-pituitary-adrenal (HPA) axis is stimulated and catecholamine production is increased. Adrenomedullin (ADM) is a novel peptide that elicits a long-vasorelaxation, and participates in blood pressure regulation via different mechanisms. In the present study, we investigated the administration of ADM on tyrosine hydroxylase (TH) enzyme activity in cold exposed rats. Four groups of Sprague-Dawley rats were studied for their TH enzyme activity in the adrenal medulla and hypothalamus. In addition to measuring blood pressure in these rats, TH enzyme activity in both the adrenal medulla and hypothalamus were examined in four groups of Sprague-Dawley rats: animals exposed to room temperature and cold stress (8degreesC, 48 h), and rats injected with ADM (1.0 nmol/kg, i.v.) alone and/or together with cold stress. TH activity was shown to be increased in cold treated groups and decreased in ADM and ADM + cold stress group. Our findings appear to suggest that external ADM application caused an opposite effect on the same system in rats, decreasing the activity of tyrosine hydroxylase (TH) enzyme activity. Furthermore, externally applied ADM was shown to produce its expected hypotensive effect in cold-stressed rats. Our results suggest that a possible explanation for the effects of ADM is that, the uptake of ADM under cold stress may effect TH activity in studied tissues.Öğe Effects of shock wave lithotripsy on plasma and urinary levels of nitrite and adrenomedullin(Springer-Verlag, 2003) Sarica, K; Balat, A; Erbagci, A; Cekmen, M; Yurekli, M; Yagci, FPurpose: In this prospective clinical study, we aimed to determine whether shockwave lithotripsy (SWL) has any specific effect on plasma as well as urinary nitrite, a stabile metabolite of nitric oxide (NO) and adrenomedullin (AM) concentrations, and to investigate whether these variables can be used as a marker for detecting shockwave-induced impairment of renal tubular and glomerular cells. Material and Methods: A total of 20 patients with renal pelvic or caliceal stones less than or equal to2 cm undergoing anesthesia-free SWL without auxiliary measures and a control group of ten patients without any urological symptoms were included in this study. The plasma and urinary concentrations of nitrite and AM were measured before, 24 h, and 7 days after SWL. Nitrite levels were measured by Griess reaction. Reverse-phase high-performance liquid chromatography (HPLC) was used to determine AM levels. Results: Application of high-energy shock waves (HESW) in our study caused a statistically significant increase in plasma levels of both NO and AM, which reflected an organized response of the kidney to this type of trauma in an attempt to maintain normal renal hemodynamics. Mean plasma nitrite concentration before SWL application was 29.9+/-7.6 mumol/l and this value was found to be 39.02+/-8.45 mumol/l at 24-h follow-up. Comparative evaluation of the plasma concentrations of AM revealed a significant increase at the 24-h examination: 20.51+/-3.0 pmol/ml and 32.54+/-4.3 pmol/l, respectively. On the other hand, comparative evaluation of urinary levels of both nitrite and AM levels before as well as 24 h after SWL application revealed a statistically significant increase related to markers. Conclusion: This first clinical study on plasma-urinary nitrite and AM levels in patients undergoing the SWL procedure indicated that plasma and urine levels of both peptides were increased. Our findings in turn suggested that SWL application to kidneycan stimulate the NO-cGMP signalling pathway to increase NO production in the kidney. Our findings also indicated that the increased levels of NO and AM secretion during renal parenchymal ischemia may be protective enough for renal pathological alterations resulting from SWL-induced renal trauma. We suggest that this increase may be a compensatory response to SWL induced injury.Öğe Increased plasma adrenomedullin levels in patients with Behcet's disease(Karger, 2000) Evereklioglu, C; Yurekli, M; Er, H; Ozbek, E; Hazneci, E; Cekmen, M; Inaloz, HSBackground: Behcet's disease (BD) is a chronic systemic inflammatory disorder affecting multiple organs with a generalized vasculitis of arteries and veins. Endothelial dysfunction is one of the prominent features of ED. Adrenomedullin (AM) is a peptide produced not only in normal adrenal medulla but also in the vascular smooth muscle cells and endothelial cells, and its role in the course of ED has not been previously described. Objective: To detect changes of plasma AM concentrations in patients with ED compared with age- and sex-matched healthy subjects by using high-performance liquid chromatography (HPCL). We also investigated if disease activity or the duration of ED correlates with ANT levels. Methods: Forty-two consecutive patients with ED (38.5 +/- 11.1 years, 19 male and 23 female) and 20 healthy age- and sex-matched control subjects (39.5 +/- 10.9 years, 8 male and 12 female) were included in this study. We measured plasma AM levels by HPCL, and acute-phase reactants including alpha (1)-antitrypsin and alpha (2)-macroglobulin, neutrophil count and the erythrocyte sedimentation rate. Results: Mean +/- SD plasma AM levels in patients with ED (73.22 +/- 25.55 pmol/l) were significantly higher (p < 0.001) than in healthy control volunteers (21.35 12.37 pmol/l). Patients with active ED had similar plasma AM concentrations (79.32 +/- 21.89 pmol/l) with patients with inactive disease (67.44 +/- 29.92 pmol/l). On the other hand, patients with longer duration of the disease (mean duration, 13.9 +/- 3.8 years) had significantly higher plasma AM levels (83.99 +/- 19.71 pmol/l; p = 0.005) than patients (62.45 +/- 26.57 pmol/l) with shorter duration of the disease (mean duration, 5.5 +/- 2.3 years). All acute-phase reaction parameters were found to be significantly increased in the active disease. Conclusion: Considering its endothelial cell implications, AM may be involved in reparatory vessel endothelium mechanisms, especially in the chronic disease. Copyright (C) 2000 S. Karger G, Basel.Öğe Influence of misoprostol (PGE1) on amniotic fluid and maternal serum adrenomedullin levels(Wiley, 2005) Hascalik, S; Celik, O; Dogru, MI; Dogru, AK; Inan, E; Yurekli, MObjective. The purpose of this study was to determine the levels of adrenomedullin (AdM) in amniotic fluid (AF) and maternal serum of misoprostol (PGE1)-induced pregnant women. Materials and methods. A total of 40 women were included in the study: 20 were in active labor and were delivered vaginally and a further 20 were not in labor and misoprostol induction was performed. Women who were undergoing labor induction received 50 mu g of misoprostol, which was placed in the posterior fornix of the vagina every 4 hrs until the onset of labor. In each patient, maternal plasma and AF samples were collected. Samples of AF were collected by transvaginal route at the time of rupture of the membranes. The labor was at the same stage in both the groups during the sample collection. In all pregnant subjects, maternal blood samples were drawn from the cubital vein at the time of AF sampling. Amniotic fluid and serum AdM concentration was measured by using reverse-phase high-performance liquid chromatography. Results. Misoprostol-induced pregnant women showed significantly higher AdM concentrations than control pregnant women in AF (79.48 +/- 6.14 pmol/ml versus 21.28 +/- 0.90 pmol/ml, P = 0.000) and maternal serum (88.20 +/- 4.34 pmol/ml versus 29.78 +/- 4.51 pmol/ml, P = 0.000). There was no significant difference between maternal serum and AF-AdM concentrations in misoprostol and control subjects. Conclusion. Increased serum and AF-AdM concentrations may be necessary to initiate cervical ripening in misoprostol-induced pregnant women.Öğe The investigation of levels of the peptide adrenomedullin (ADM) and the enzyme tyrosine hydroxylase (TH) in rat tissue after exposure to physiological stress(Wiley, 2006) Yurekli, M; Yarpuzlu, AAAn organism's ability to respond to the external and internal environments is explained in terms of the concept of biological stress. The causes of these responses are called stressors. They may be physical, chemical, emotional, or traumatic. With continued exposure to the stressor the organism enters the stage of resistance and defense. After prolonged exposure to the same stressor the organism may enter the stage of exhaustion. Catecholamines have an important role in maintaining biological homeostasis to stress. Catecholamine biosynthesis starts from tyrosine and in the first step DOPA is synthesized from tyrosine and catalyzed by the enzyme tyrosine hydroxylase (TH). In rats this enzyme activity varies depending on cold stress, exercise and age. The production of adrenomedullin in adrenal medulla, heart and brain also suggest a role for this peptide in the physiological control of homeostasis. In this study TH enzyme activity and adrenomedullin levels were investigated in rat tissues that were excised from animals exposed to 8 degrees C cold for 3 weeks. After cold exposure TH enzyme activities and adrenomedullin levels were changed but also age was found to be a factor. Copyright (c) 2006 John Wiley & Sons, Ltd.Öğe Protective role of caffeic acid phenethyl ester in the liver of rats exposed to cold stress(Wiley-Blackwell, 2006) Ates, B; Dogru, MI; Gul, M; Erdogan, A; Dogru, AK; Yilmaz, I; Yurekli, MCold exposure can induce a form of environmental stress. Cold stress (CS) alters homeostasis, results in the creation of reactive oxygen species and leads to alterations in the antioxidant defense system. The caffeic acid phenethyl ester (CAPE), an active component of propolis, has an antioxidant capacity. We investigated the effect of CS on oxidative stress and antioxidant defense system and the possible protective effect of CAPE in rat liver tissue. Twenty-four female Wistar Albino rats were divided into four groups: Control, CAPE-treated, CS, and CAPE-treated CS (CS + CAPE) group. Catalase (CAT), glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) activities and total glutathione (GSH) and malondialdehyde (MDA) levels were measured. In addition, histological changes in liver tissue were examined by light microscopy. SOD, CAT and GSH-Px activities and total GSH level were significantly declined in the CS group. In the CS + CAPE group, the activities of these three enzymes and GSH level significantly raised with regard to the CS group. MDA levels increased in the CS group and decreased in the CS + CAPE group. The tissues of the CS group showed some histopathological changes such as necrosis, hepatocyte degeneration, sinusoidal dilatation, hemorrhage and vascular congestion and dilatation. In the CS + CAPE group, the histopathological evidence of hepatic damage was markedly reduced. Histological parameters were consistent with biochemical parameters. In this study, CS increased oxidative stress in liver tissue. CAPE regulated antioxidant enzymes, inhibited lipid peroxidation and reduced hepatic damage.Öğe The role of adrenomedullin in varicocele and impotence(Blackwell Science Ltd, 2000) Ozbek, E; Yurekli, M; Soylu, A; Davarci, M; Balbay, MDObjective To assess the levels of adrenomedullin (a vasodilatory peptide) in penile blood before and after injection with papaverine in impotent men, and in the internal spermatic vein in infertile patients with varicocele, comparing the results with levels in the brachial vein in the same patients. Patients and methods Intracavernosal levels of adrenomedullin were determined in 14 impotent men (with no vascular pathology, as assessed by colour Doppler ultrasonography) before and after papaverine-induced penile erection. The effect of needle puncture alone was assessed in eight control patients. The level of adrenomedullin was also measured in the internal spermatic vein and brachial vein in 14 infertile men with varicocele. Results The mean (SD) intracavernosal adrenomedullin levels in the 14 impotent men were significantly different between the flaccid and papaverine-induced erectile state, at 93.5 (33.0) and 135.8 (34.9) pmol/mL, respectively, (P < 0.05). Needle puncture alone had no effect on adrenomedullin levels. In men with varicocele, the adrenomedullin level of 139.0 (34.3) pmol/mL within the internal spermatic vein was significantly higher than that in the brachial vein, at 103.9 (37.6) pmol/mL (P < 0.05). Conclusion Injection with papaverine increases adrenomedullin release into penile blood; this release may be responsible for the increase in penile blood flow and penile erection. Higher levels of adrenomedullin within the internal spermatic vein of patients with varicocele may result from the retrograde flow of venous blood from the left adrenal gland and kidney. Further studies are needed to determine the role of adrenomedullin in male infertility and impotence.Öğe Subacute toxicity of uranyl acetate in Swiss-Albino mice(Elsevier, 1998) Ozmen, M; Yurekli, MSubacute effects of uranyl acetate were investigated in laboratory mice (Mus musculus, Swiss-Albino). Uranyl acetate was administrated to mice during a period of 5 days with dietary consumption ad libitum. Effects of uranyl acetate on food and water consumption, body weight changes; plasma urea nitrogen (:BUN), creatinine concentrations and activities of alkaline phosphatase (ALP), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were assayed by time-course experiment. Glutathione S-transferase (GST) and catalase (CAT) activities were also determined in liver tissues on day 5. Distribution of radioactivity in liver, kidney and brain was detected by scintillation spectrometry. The results indicated that uranyl acetate was accumulated in examined tissues, with highest accumulation being in brain. Some of the biochemical biomarkers (BUN, creatinine, ALP) were significantly increased (P < 0.05) in the exposure group compared to control animals. Also, BUN and/or creatinine levels and/or ALT and AST activities significantly increased (P < 0.01 or P < 0.05) with UA exposure on day 3 and/or day 5 compared with results of day 1. (C) 1998 Elsevier Science B.V. All rights reserved.Öğe Tyrosine hydroxylase (TH) enzyme activity and adrenomedullin (AdM) level in ovariectomized rat tissues depend on tamoxifen(Federation Amer Soc Exp Biol, 2001) Dogru, MI; Yurekli, M; Kocagun, A; Gokdeniz, R[Abstract Not Available]Öğe Tyrosine hydroxylase levels in colon adenocarcinomas.(Amer Assoc Clinical Chemistry, 2000) Akbay, A; Yurekli, M; Eroglu, A; Demirtas, S; Sunguroglu, K[Abstract Not Available]
