A novel marker in acute central serous chorioretinopathy: thiol/disulfide homeostasis.

PURPOSE: The aim of this study was to compare dynamic thiol/disulfide homeostatic status in acute central serous chorioretinopathy (CSCR) patients by using a novel and automated assay determining dynamic thiol/disulfide homeostasis. METHODS: Fifty-one patients with acute CSCR (study group) and 65 healthy individuals (control group) were enrolled in this study. Diagnosis of acute CSCR was made clinically and using spectral-domain RTVue OCT (optical coherence tomography) (Optovue, Fremont, CA). Fluorescein angiography confirmed the diagnosis of acute CSCR in all subjects. Total thiol, native thiol, disulfide amount, and native thiol/disulfide ratio (TDR) were calculated in the blood samples. RESULTS: Mean total thiol, native thiol, and native TDR values were lower in patients with acute CSCR (364.2 ± 14.1, 326.4 ± 13.2, 17.14 ± 1.9, respectively) than in healthy eyes (441.2 ± 16.3, 398.5 ± 16.4, 22.70 ± 2.15, respectively; mean total thiol, p = 0.017; native thiol, p = 0.011; native TDR, p = 0.031). CONCLUSIONS: Total thiol, native thiol, and native TDR were significantly lower statistically in patients with acute CSCR when compared with healthy controls.

The change in serum Thiol/Disulphide homeostasis after transrectal ultrasound guided prostate biopsy.

OBJECTIVES: The aim of this prospective clinical study was to investigate variations in a novel oxidative stress marker (thiol/disulphide homeostasis) in men who underwent transrectal ultrasound guided prostate biopsy (TRUSB). MATERIALS AND METHODS: A total of 22 men undergoing TRUSB of the prostate were enrolled in the study. Patients with abnormal digital rectal examination and/or total prostate specific antigen (PSA) over 4ng/mL underwent TRUSB with 12 cores. Serum samples were obtained before and just after the procedure to evaluate the possible changes in thiol/disulphide homeostasis. Mean age, total PSA and free PSA, prostate volume and histopathological data were also recorded. RESULTS: Mean age of the study population was 65.05±8.89 years. Significant decreases in native and total thiol levels were documented after the biopsy procedure. However, serum disulphide levels and disulphide/native thiol, disulphide/total thiol and native / total thiol ratios did not significantly change after TRUSB. No correlation was observed between oxidative parameters and total PSA and free PSA levels, prostate volume and histopathology of the prostate. However, mean patient age was significantly correlated with mean native and total thiol levels. CONCLUSION: Significant decreases in serum native and total thiol levels related to the prostate biopsy procedure suggest that TRUSB causes acute oxidative stress in the human body. Since our trial is the first in the current literature to investigate these oxidative stress markers in urology practice, additional studies are warranted.

Anti-Müllerian hormone as a marker of premature ovarian aging in autoimmune thyroid disease.

There is an increased incidence of autoimmune thyroid disease (AITD) in women with infertility. We hypothesized that serum anti-Müllerian hormone (AMH) levels will be lower in premenopausal women with AITD than controls. We evaluated ovarian reserve in women with AITD (n = 85) and healthy controls (n = 80), all <40 years old. Detailed data on reproductive history were obtained. Gonadotrophins, steroids, AMH, and inhibin B levels were measured during the follicular phase. The number of pregnancies as well as live births was lower in women with AITD (p < 0.01). No difference was observed in terms of FSH, estradiol, and inhibin B. AMH levels were lower in AITD women than in controls (1.16 + 0.17 versus 1.28 + 0.25 ng/ml, mean + SD, p = 0.001). According to the multiple regression analysis, even after age adjustment, AITD was significantly and independently affected AMH levels (t = 2.674, p = 0.008). Women with AITD seem to have a diminished ovarian follicular reserve and measurement of serum AMH level has the potential to be used to predict this comorbidity.

Value of caffeic acid phenethyl ester pretreatment in experimental sepsis model in rats.

BACKGROUND AND AIM: The aim of this study was to determine the actions of caffeic acid phenethyl ester (CAPE) on the changes of endothelin-1 (ET-1) level, tumor necrosis factor- (TNF-) alpha, and oxidative stress parameters such as superoxide dismutase (SOD) activities and malondialdehyde (MDA) levels in experimental sepsis model in rats. MATERIALS AND METHODS: Twenty-four rats were randomly divided into three experimental groups: sham (group 1), sepsis (group 2), and sepsis + CAPE (group 3), n = 8 each. CAPE was administered (10 µmol/kg) intraperitoneally to group 3 before sepsis induction. Serum ET-1, serum TNF-alpha, tissue SOD activity, and tissue MDA levels were measured in all groups. RESULTS: Pretreatment with CAPE decreased ET-1, TNF-alpha, and MDA levels in sepsis induced rats. Additionally SOD activities were higher in rats pretreated with CAPE after sepsis induction. CONCLUSION: Our results demonstrate that CAPE may have a beneficial effect on ET and TNF-alpha levels and oxidative stress parameters induced by sepsis in experimental rat models. Therefore treatment with CAPE can be used to avoid devastating effects of sepsis.

Assessment of fetal antioxidant and oxidant status during different anesthesia techniques for elective cesarean sections.

BACKGROUND: We aimed to investigate the effects of general, spinal and epidural anesthesia on fetal total antioxidant status (TAS) and total oxidant status (TOS), and oxidative stress index (OSI) during elective cesarean section in this study. MATERIALS AND METHODS: Forty-seven parturients scheduled for elective cesarean section were randomly allocated into three groups: Group spinal (n = 15), group epidural (n = 17), and group general (n = 15), This prospective randomized study was performed in Faculty of Medicine, Turgut Ozal University, Turkey. After the baby was delivered; TAS, TOS levels, and arterial blood gases parameters were analyzed in an umbilical arterial blood sample. OSI values are calculated by a ratio of TOS to the TAS. RESULTS: The levels of TAS and TOS in umbilical arterial blood sample were not statistically different among three. However, OSI values were significantly different among the three groups (P = 0.042). Median OSI values is 24 (interquartile range [IQR], 2-37) in group spinal, 19 (IQR, 4-44) in group epidural, and 8 (IQR, 4-36) in group general. There was no significant difference in OSI values in the comparison of group spinal with group general and group epidural, but it was significantly lower in group general when compared with group epidural with Bonferroni correction (P = 0.017). Umbilical cord arterial blood gas values (pH, PaCO2, PaO2, SaO2, HCO3, and CtO2), glucose, lactate, and hemoglobin levels were similar in three groups. CONCLUSION: General anesthesia may be more favorable than epidural in those undergoing cesarean section when fetal oxidative status gains importance.

The platelet activating factor acetyl hydrolase, oxidized low-density lipoprotein, paraoxonase 1 and arylesterase levels in treated and untreated patients with polycystic ovary syndrome.

PURPOSE: To evaluate the platelet activating factor acetyl hydrolyze (PAF-AH), oxidized low-density lipoprotein (ox-LDL), paraoxonase 1 (PON1), arylesterase (ARE) levels and the effects of metformin and Diane-35 (ethinyl oestradiol + cyproterone acetate) therapies on these parameters and to determine the PON1 polymorphisms among PCOS patients. METHODS: Ninety patients with PCOS, age 30, and body mass index-matched healthy controls were included in the study. Patients were divided into three groups: metformin treatment, Diane-35 treatment and no medication groups. The treatment with metformin or Diane-35 was continued for 6 months and all subjects were evaluated with clinical and biochemical parameters 6 months later. One-way Anova test, t test and non-parametric Mann-Whitney U tests were used for statistical analysis. RESULTS: PAF-AH and ox-LDL levels were statistically significantly higher in untreated PCOS patients than controls, and they were statistically significantly lower in patients treated with metformin or Diane-35 than untreated PCOS patients. In contrast, there were lower PON1 (not statistically significant) and ARE (statistically significant) levels in untreated PCOS patients than the control group and they significantly increased after metformin and Diane-35 treatments. In PCOS patients serum PON1 levels for QQ, QR and RR phenotypes were statistically significantly lower than the control group. CONCLUSION: In patients with PCOS, proatherogenic markers increase. The treatment of PCOS with metformin or Diane-35 had positive effects on lipid profile, increased PON1 level, which is a protector from atherosclerosis and decreased the proatherogenic PAF-AH and ox-LDL levels.

Is IL-33 useful to detect early stage of renal failure?

IL-33 is a proinflammatory cytokine that is a member of IL-1 family. Previously the effect of IL-33 on kidney injury is showed in animal models. In this study, we searched if we can use IL-33 to show the early stage of kidney injury in diabetic patients. Three groups are identified: 26 patients in Group 1: Healthy group, that do not have any chronic diseases and not taking any medication; 42 patients in Group 2: DM (diabetes mellitus) group without any known kidney disease and with normal kidney functions; 32 patients in Group 3: DM + MA (microalbuminuria) group that are assumed to have nephropathy. IL-33 level of DM patient group is greater than healthy group; also IL-33 level of DM + MA patient group is greater than healthy group; but there is not any difference between DM and DM + MA group. The increase in IL-33 levels in diabetic nephropathy is not associated with kidney injury but the increase could be resulting because of diabetes. So IL-33 cannot be used in early recognition of diabetic nephropathy.

Levels of thrombin activatable fibrinolysis inhibitor in gestational diabetes mellitus.

Thrombin-activatable fibrinolysis inhibitor (TAFI) is a procarboxypeptidase, which is synthesised in liver and activated by thrombin and the thrombin-thrombomodulin complex. TAFI suppresses fibrinolysis by removing carboxy-terminal lysine residues from partially degraded fibrin. In this study we aimed to assess the circulating levels of TAFI antigen, 'a fibrinolytic parameter' in women with gestational diabetes (GDM). Thirty-four pregnant women with GDM and 50 pregnant women with normal glucose tolerance were included in the study. Plasma TAFI antigen levels were significantly higher in pregnant women with GDM when compared with controls. Increased TAFI levels may contribute to the decreased fibrinolytic potency, causing a thrombophilic state. GDM is regarded as a specific form of diabetes, and it could in addition be a predictor of type 2 diabetes mellitus in the future and the risk of complications due to hypercoagulability increases in this disease. Increased TAFI levels may also have a role in increased risk of hypercoagulability.

Determination of total oxidative stress and total antioxidant capacity before and after the treatment of iron-deficiency anemia.

BACKGROUND: Oxidative stress is an imbalance between the reactive oxygen species and antioxidant system. In this study, total oxidative stress (TOS) and total antioxidant capacity (TAC) were investigated with a new and practical method in childhood iron-deficiency anemia. METHOD: During the study period 80 children between 6 and 60 months were enrolled; 40 children (study group) had iron-deficiency anemia, and 40 children (control group) were healthy. Complete blood count, serum iron, iron-binding capacity, ferritin levels, TOS, and TAC were evaluated. Children diagnosed iron-deficiency anemia were treated with oral ferric iron. After 2 months of the treatment, blood tests of the study groups were repeated to check the challenge. RESULTS: TAC was similar between both groups (1.55 ± 0.26 in control group 1.53 ± 0.19 mmol Trolox Eq./l). Additionally, TOS was significantly higher in iron-deficiency anemia group before treatment with iron (24.3 ± 18.5, in controls groups 14.4 ± 7.1 mmol Trolox Eq./l). We have shown that TAC did not change (before treatment 1.55 ± 0.26, after treatment 1.54 ± 0.26 mmol Trolox Eq./l) although TOS decreased significantly after the treatment of iron-deficiency anemia (before treatment 24.3 ± 18.5, after treatment 12.4 ± 6.9 mmol Trolox Eq./l). We did not find any correlation between hemoglobin, serum iron, iron-binding capacity, ferritin levels, and TOS or TAC among iron-deficiency anemia patients. CONCLUSION: As a result of this study, oxidative stress increases in children with iron-deficiency anemia and this increase can be returned to normal levels by treatment.

Changes in growth pattern, leptin ghrelin and neuropeptide Y levels after adenotonsillectomy in prepubertal children.

AIM: The purpose of this prospective study was to evaluate whether surgical treatment of adenotonsillar hypertrophy has an effect on growth patterns and circulating concentrations of leptin, ghrelin and neuropeptide Y, which are all significant in energy balance. MATERIALS AND METHODS: The study group consisted of 20 children who underwent tonsillectomy with or without adenoidectomy due to chronic adenotonsillar hypertrophy. The ages ranged from 4.3 to 9.2 years with normal weight. The healthy control subjects consisted of 30 age- and sex-matched children (control group) with ages between 3.2 and 8.1 years. Serum levels of leptin ghrelin and neuropeptide Y were measured in the preoperative period and at the end of the postoperative period, which was 6 months in the study group, serum levels were only measured during the first examination in the control group. RESULTS: When the study group (preoperative) is compared with the control group, it is observed that the leptin and ghrelin levels were higher in the study group and that the neuropeptide Y levels were similar (p=0.01, p=0.005, p=0.19, respectively). When the preoperative and postoperative anthropometric data were compared, it was observed that weight, height, body mass index (BMI) and BMI-standard deviation score (SDS) values increased in the 6th month postoperatively (p<0.001, p<0.001, p=0.01, p=0.03, respectively). However, the leptin, ghrelin and neuropeptide Y levels were similar (p=0.70, p=0.12, p=0.60, respectively). CONCLUSION: Following adenotonsillectomy, an increase in weight and height occurred in the children. In the postoperative period, dietary and lifestyle suggestions as well as growth monitoring might be useful.

Zyflamend suppresses growth and sensitizes human pancreatic tumors to gemcitabine in an orthotopic mouse model through modulation of multiple targets.

Agents that can potentiate the efficacy of standard chemotherapy against pancreatic cancer are of great interest. Because of their low cost and safety, patients commonly use a variety of dietary supplements, although evidence of their efficacy is often lacking. One such commonly used food supplement is Zyflamend, a polyherbal preparation with potent anti-inflammatory activities and preclinical efficacy against prostate and oral cancer. Whether Zyflamend has any efficacy against human pancreatic cancer alone or in combination with gemcitibine, a commonly used agent, was examined in cell cultures and in an orthotopic mouse model. In vitro, Zyflamend inhibited the proliferation of pancreatic cancer cell lines regardless of p53 status and also enhanced gemcitabine-induced apoptosis. This finding correlated with inhibition of NF-κB activation by Zyflamend and suppression of cyclin D1, c-myc, COX-2, Bcl-2, IAP, survivin, VEGF, ICAM-1 and CXCR4. In nude mice, oral administration of Zyflamend alone significantly inhibited the growth of orthotopically transplanted human pancreatic tumors, and when combined with gemcitabine, further enhanced the antitumor effects. Immunohistochemical and Western blot analyses of tumor tissue showed that the suppression of pancreatic cancer growth correlated with inhibition of proliferation index marker (Ki-67), COX-2, MMP-9, NF-κB and VEGF. Overall, these results suggest that the concentrated multiherb product Zyflamend alone can inhibit the growth of human pancreatic tumors and, in addition, can sensitize pancreatic cancers to gemcitabine through the suppression of multiple targets linked to tumorigenesis.

Low plasma vitamin D levels in patients with familial Mediterranean fever.

Familial Mediterranean fever (FMF) is an autosomal recessive, inherited autoinflammatory disease characterized by recurrent, self-limited attacks of fever and inflammation of serosal surfaces. There is an explosion of the data regarding inflammatory markers in FMF and clinical effects of chronic inflammation on the disease presentation. Vitamin D (vit D) is the common denomination of a group of sterols with a crucial role in phospho-calcium metabolism. There are some data about the importance of vit D in the initiation and propogation of a range of autoimmune diseases. The aim of the present study was to determine whether vit D deficiency is present in patients with FMF compared with healthy individuals. The study group included 99 patients with diagnosis of FMF attended to our outpatient Rheumatology and Nephrology Clinics of Atatürk Education and Research Hospital. The control group comprised 51 age- and sex-matched healthy people selected from hospital staff. Serum baseline 25-hydroxy vit D levels were measured by HPLC method using an Agilent 1100 Liquid Chromatograph. We found significantly lower serum 25-hydroxy vit D levels among FMF patients compared with matched controls and a high prevalence of vit D deficiency. This study demonstrated that vit D deficiency is frequent in patients with FMF than the healthy controls. It is convenient to look for vit D deficiency and to correct vit D nutritional status in FMF patients.

Serum platelet-activating factor acetylhydrolase activity: relationship with metabolic syndrome in women with history of gestational diabetes mellitus.

OBJECTIVE: The aim of this study was to evaluate plasma platelet-activating factor acetylhydrolase (PAF-AH) activity in euglycaemic women with history of gestational diabetes (GDM), and to explore whether this activity is associated with metabolic syndrome (MS) in this group of women. METHODS: The cross-sectional study included 36 women with history of GDM and 40 women with history of normal glucose tolerance in pregnancy (control group). RESULTS: Compared to the controls, the GDM group had significantly higher mean values for serum glucose, insulin, HOMA-IR, triglyceride, GGT and plasma PAF-AH activity, and a statistically higher prevalence of MS. Within the GDM group, women diagnosed with MS had significantly higher PAF-AH activity than those without MS (p=0.002). CONCLUSION: This is the first study to have shown that plasma PAF-AH activity and GGT levels may be significant for evaluating atherosclerosis risk and metabolic hepatic damage in women with history of GDM.

Effects of erdosteine on cyclosporine-A-induced hepatotoxicity in rats.

Cyclosporine A (CsA) is a potent immunosuppressive agent used for organ transplantations and various autoimmune disorders. However, hepatotoxicity due to CsA remains one of the major side effects. The use of antioxidants reduces the adverse effects of CsA. The aim of this study was to determine the protective effects of erdosteine on CsA-induced liver injury through tissue oxidant/antioxidant parameters and to evaluate light microscopic alterations in rat-liver tissues. Rats were randomly divided into four experimental groups: The control group received sunflower oil (2 mL/kg/day, per orally; p.o.), while the other groups were treated with CsA (25 mg/kg/day, p.o.) or erdosteine (10 mg/kg/day, p.o.) or CsA+erdosteine, respectively. Serum aspartate aminotransferase and alanine aminotransferase levels, tissue malondialdehyde and nitric oxide levels, and superoxide dismutase, glutathione peroxidase and catalase enzyme activities were measured. Histological examination was performed. CsA caused a significant deterioration in the hepatic function tests, morphology, and gave rise to severe oxidative stress in the liver. Erdostein significantly improved the functional and histological parameters and attenuated the oxidative stresss induced by CsA. Erdostein protects liver tissue against oxygen free radicals and prevents hepatic dysfunction and morphological abnormalities associated with chronic CsA administration.

Antioxidant effects of curcumin in spinal cord injury in rats.

BACKGROUND: This experimental study was performed to investigate the benefit of curcumin via its antioxidant effect on spinal cord injury (SCI) in rats. METHODS: Twenty-four adult Wistar albino rats were randomized into three groups. SCI was performed by the weight-drop model. Group 1 underwent laminectomy followed by SCI and received no medication. Group 2 underwent laminectomy followed by SCI and received curcumin (200 mg/kg/day orally). Group 3 underwent laminectomy followed by SCI and received methylprednisolone (30 mg/kg intraperitoneally). Twenty-four hours later, blood samples were obtained from all rats; serum superoxide dismutase (SOD) and malondialdehyde (MDA) levels were determined, and the obtained results were compared. RESULTS: SOD level in the curcumin group was higher than in the control group (p < 0.000) and methylprednisolone group (p < 0.012). MDA level in the curcumin group was lower than in the control group (p < 0.042). Similarly, the MDA level in the methylprednisolone group was lower than in the control group (p < 0.001). CONCLUSION: The results of the present study show that curcumin effectively protects the spinal cord tissues against oxidative damage.

Treatment of Nigella sativa in experimental sepsis model in rats.

This experimental study was designed to determine effects of Nigella sativa oil (NSO) on endothelin-1 (ET-1) level and oxidative stress parameters, superoxide dismutase (SOD) and malondialdehyde (MDA) in a rat sepsis model. Twenty four adult Wistar albino rats were divided randomly into three groups: sham group (group 1), sepsis group (group 2), sepsis group pretreated with NSO (group 3). Serum ET-1, tissue SOD and tissue MDA levels were measured in all groups. Compared to group 1, ET-1 and MDA levels were higher in group 2. ET-1 and MDA levels in NSO pretreated group 3 were lower with respect to group 2 (p<0.03, and p<0.02, respectively). Additionally, SOD levels in group 3 were found to be higher than group 2 (p<0.02). Based on our results, it can be concluded that NSO may have a positive impact on ET-1 levels and oxidative stress induced by sepsis in experimental rat models.

Association of visceral fat accumulation and adiponectin levels with colorectal neoplasia.

PURPOSE: There are few studies addressing the association between measured values of visceral fat accumulation (VFA), adiponectin, and colorectal neoplasia. Our purpose is to investigate the association of VFA and serum adiponectin levels with colorectal adenoma and carcinoma patients. For this purpose, 54 patients with colorectal adenoma and carcinoma, diagnosed by colonoscopic evaluation, and 50 healthy control subjects were included. Patients were subjected to measurement of VFA and adiponectin level and calculation of insulin resistance. RESULTS: Patients with colorectal carcinoma had lower plasma adiponectin levels compared with controls. VFA level did not differ between patients and controls. Adiponectin level was found to be uncorrelated with VFA in the colorectal cancer and adenoma group. No correlation was found between insulin resistance and plasma adiponectin level and VFA. CONCLUSION: Our findings suggest that decreased plasma adiponectin level may be a factor involved in the development of colon cancer or a secondary effect of the metabolic derangements in colorectal cancer.

Linkage disequilibrium mapping of a breast cancer susceptibility locus near RAI/PPP1R13L/iASPP.

BACKGROUND: Previous results have suggested an association of the region of 19q13.3 with several forms of cancer. In the present study, we investigated 27 public markers within a previously identified 69 kb stretch of chromosome 19q for association with breast cancer by using linkage disequilibrium mapping. The study groups included 434 postmenopausal breast cancer cases and an identical number of individually matched controls. METHODS AND RESULTS: Studying one marker at a time, we found a region spanning the gene RAI (alias PPP1R13L or iASPP) and the 5' portion of XPD to be associated with this cancer. The region corresponds to a haplotype block, in which there seems to be very limited recombination in the Danish population. Studying combinations of markers, we found that two to four neighboring markers gave the most consistent and strongest result. The haplotypes with strongest association with cancers were located in the gene RAI and just 3' to the gene. Coinciding peaks were seen in the region of RAI in groups of women of different age. In a follow-up to these results we sequenced 10 cases and 10 controls in a 44 kb region spanning the peaks of association. This revealed 106 polymorphisms, many of which were not in the public databases. We tested an additional 44 of these for association with disease and found a new tandem repeat marker, called RAI-3'd1, located downstream of the transcribed region of RAI, which was more strongly associated with breast cancer than any other marker we have tested (RR = 2.44 (1.41-4.23, p = 0.0008, all cases; RR = 6.29 (1.49-26.6), p = 0.01, cases up to 55 years of age). CONCLUSION: We expect the marker RAI-3'd1 to be (part of) the cause for the association of the chromosome 19q13.3 region's association with cancer.

Increased thrombin-activatable fibrinolysis inhibitor antigen levels as a clue for prothrombotic state in polycystic ovary syndrome.

OBJECTIVES: Our study was undertaken to evaluate the levels of thrombin-activatable fibrinolysis inhibitor (TAFI) antigen and also its relationship with other hemostasis markers in a group of patients affected with polycystic ovary syndrome (PCOS)-under Diane-35 (ethinyl estradiol 0.035 mg/cyproterone acetate 2 mg) treatment or not-as compared with a group of healthy controls. METHODS: Forty-two women with PCOS and 30 age-matched healthy controls were involved in the study. Group A were on Diane-35 for at least 6 months; group B did not take any drug; group C served as a control group. RESULTS: TAFI antigen levels of groups A and B were significantly higher than in controls, but no difference was observed between them. All of the other coagulation and fibrinolysis parameters (including prothrombin time, activated partial thromboplastin time, fibrinogen and D-dimer) were comparable between the three groups. CONCLUSION: The evidence presented herein suggests that women with PCOS have impaired fibrinolysis, as reflected by increased TAFI. This impairment can contribute to the risk of cardiovascular disease in PCOS. Elucidation of the modifiable mechanisms in PCOS can represent an opportunity for preventive therapy of the cardiovascular risks associated with PCOS.

Comparison of effects of darbepoetin alfa and epoetin alfa on serum endothelin level and blood pressure.

It is well known that epoetin alfa increases serum endothelin (ET)-1 and blood pressure. No data are available, however, on the effects of darbepoetin alfa on serum ET-1 and blood pressure. This study was conducted to compare the effects of darbepoetin alfa and epoetin alfa on serum ET-1 and blood pressure in patients on hemodialysis (HD). A total of 42 patients on HD were included in the study. Serum samples for measuring levels of ET-1 were taken 30 min after administration of epoetin alfa. After blood samples had been taken from all patients, epoetin alfa was changed to darbepoetin alfa. Three months after the start of darbepoetin alfa treatment, blood samples were taken to measure the same parameters. Mean arterial blood pressure was measured before recombinant human erythropoietin (EPO) administration and 30 min after EPO administration while patients were taking epoetin alfa or darbepoetin alfa. Injection of epoetin alfa or darbepoetin alfa significantly increased serum ET-1 levels compared with levels in those patients who were not on EPO therapy (P<.05). When the effects of epoetin alfa on serum ET-1 level were compared with those of darbepoetin alfa, the 2 types of EPO were found to increase serum ET-1 levels similarly (P>.05). Administration of epoetin alfa or darbepoetin alfa increased systolic and diastolic blood pressures significantly over values in the control group (P<.05). Serum systolic and diastolic blood pressures increased similarly after injection of epoetin alfa or darbepoetin alfa. Administration of darbepoetin alfa increased blood pressure in patients on HD in a way that was positively correlated with enhanced ET-1 release; a similar correlation was noted with epoetin alfa.