Significance of Nitric Oxide Level in Giardiasis.

BACKGROUND: Giardiasis is one of the most prevalent intestinal protozoa infections in humans. Nowadays, nitric oxide (NO) is known to be involved in the immune system against Giardia intestinalis. Therefore, the aim of the present study was to evaluate the level of NO in individuals with giardiasis in comparison to normal subjects. METHODS: This descriptive study was conducted among 49 Giadia positive and 39 age and gender matched healthy volunteers. Examination of stool samples was done by wet mount technique and formol-ether concentration method. Serum samples were obtained for laboratory examination. NO production was quantified by measuring nitrite, a stable end product of NO, using the Griess reaction based on ELISA method. By using the standard curve in Excel program, the concentration of NO2- in samples was obtained. Finally, all data were analyzed using SPSS version 17. RESULTS: Values obtained from NO assays were placed into 4 groups: ≤ 10 (decline), 10.01 - 15 (normal), 15.01 - 25 (increase), and more than 25 µM (sharp increase). The mean level of NO in patients with G. intestinalis was 32.19 ± 2.15 µM and in people without G. intestinalis was 17.1 ± 1.33 µM. Eight point two percent of patients with Giardiasis were in normal range, but 2%, 20.4%, and 69.4% were in decline, increase, and sharp increase ranges, respectively. In group 2 (without infection), 17.9% were in normal range, and 20.5%, 51.3%, and 10.3% were in decline, increase, and sharp increase ranges, respectively. There was a statistical difference in nitric oxide levels between positive and negative groups with a 95% confidence interval. (p-value = 0.001). CONCLUSIONS: In our study, the number of people who showed a sharp increase in NO levels was significantly higher in individuals with giardiasis as compared to the control group, and patients infected with giardiasis showed significant increase in NO levels. Therefore, we suggest that further studies are required to understand the exact function of NO in the immune system against giardiasis in humans. It will be important to offer a new therapeutic target for eliminating G. intestinalis.

Evidence for Alteration in Serum Concentrations of Leptin in Infertile Men Categorized Based on BMI.

BACKGROUND: The aim of this study is to compare serum and seminal level of leptin in the context of infertility in men according to BMI. We also investigated the possible correlation of circulating level of leptin with fertility indices. METHODS: This case-control study was conducted on 193 men who consecutively attended a referral outpatient infertility clinic of Shariati Hospital. The leptin level in serum and seminal plasma were quantified by enzymelinked immunosorbent assay (ELISA) in fertile men (n = 95) and infertile men (n = 98). All participant were ageand BMI-matched. Semen was also analyzed in terms of volume, sperm concentration (106/mL), motility (%), and morphology in all subjects prior to study. Based on body mass index (BMI) value, all participants were divided into three groups; lean, body mass index (BMI) 19 - 24.99kg/m2, overweight, BMI 25 - 29.99 kg/m2, and obese BMI ≥ 30 kg/m2. RESULTS: Fertile and infertile men were significantly compatible regarding sperm concentration; however, we found no significant difference in case of the leptin level in serum and semen between the two studied groups (p-value = 0.5 and p-value = 0.1, respectively). In the infertile group, serum leptin level was significantly correlated with BMI (r = -0.291; p = 0.004 for the fertile group). Moreover, there was an inverse correlation between serum leptin level and sperm motility (r = -0.241; p = 0.014) in infertile men. Interestingly, among the infertile group, we observed an augmented serum level of leptin in obese men in comparison with lean (p = 0.009) and overweight (p = 0.07) individuals. CONCLUSIONS: Our findings along with other studies support this concept that increased BMI is of clinical relevance in the context of infertility in men since our data revealed an inverse correlation between seminal leptin level and BMI in infertile men. Specifically, alteration in serum level of leptin was obviously different in infertile men in terms of overweight and obesity. However, more studies are required to unravel obscure issues in this regard.

A positive correlation of serum SFRP1 levels with the risk of developing type 2 diabetes mellitus: a case-control study.

OBJECTIVE: Secreted frizzled-related protein 1 (SFRP1) is an adipokine whose production is significantly altered in metabolic disorders. Considering the relationship between dysfunction of Wnt/ß-catenin signaling and metabolic disorders as well as the inhibitory effects of SFRP1 on this signaling pathway, the present work aimed to investigate the correlation between serum SFRP1 levels and type 2 diabetes mellitus (T2DM) and its developing risk factors for the first time. METHODS: This case-control study measured serum levels of SFRP1, tumor necrosis factor (TNF)-α, interleukin (IL)-6, adiponectin, and fasting insulin using enzyme-linked immunosorbent assay kits in 80 T2DM patients and 80 healthy individuals. Biochemical parameters were determined using the AutoAnalyzer instrument. RESULTS: The T2DM group had higher levels of SFRP1 compared with the controls (146.8100 ± 43.61416 vs 81.9531 ± 32.78545 pg/mL; P < .001). There was a positive correlation between SFRP1 and insulin (r = 0.327, P = .003), TNF-α (r = 0.420, P < .001) as well as homeostatic model assessment for insulin resistance (r = 0.328, P = .003) in the T2DM group. In addition, 10-unit changes in SFRP1 levels showed the risk of T2DM in both the unadjusted (odds ratio [OR] [95% CI] = 1.564 [1.359-1.800]) and adjusted models accounting for age, gender, and body mass index (OR [95% CI] = 1.564 [1.361-1.799]; P < .001). A cut-off value of SFRP1 (105.83 pg/mL) was identified to distinguish between the T2DM patients and the healthy subjects, with sensitivity of 75.0% and specificity of 80.0%. CONCLUSION: According to our research, there was a significant and positive link between the amount of SFRP1 and the likelihood of developing T2DM as well as the related factors like insulin resistance index and TNF-α. These results indicated that SFRP1 might have a potential role in the development of T2DM.

Salivary Protein and Electrolyte Profiles during Primary Teeth Eruption: A Cross-Sectional Study.

This study aimed to assess the qualitative changes in the saliva during the process of primary teeth eruption. This cross-sectional study was conducted on 147 children from 2 to 48 months, of which 49 were in group A (no erupted primary teeth), 53 were in group B (at least one active erupting primary tooth), and 45 were in group C (eruption of all 20 primary teeth was completed). Salivary proteins were evaluated by sodium dodecyl sulfate electrophoresis with polyacrylamide gel, while the concentrations of salivary sodium, potassium, chloride, and calcium ions were evaluated by ion selective electrodes. The data were analyzed using ANOVA and Bonferroni tests (alpha = 0.05). The concentration of proteins with molecular weights of 20-30 KDa was significantly higher in group A, and it gradually decreased with age. The concentration of proteins with molecular weights of 50-60 KDa in group B was significantly lower than those of groups A and C. The calcium ion concentration in group A was significantly higher than that of the other groups. The concentration of potassium ions was minimal in group C. The proteins and electrolyte profiles of the subjects' saliva changed in the process of primary tooth eruption. The highest concentrations of proteins such as statherin, histatin, P-B peptide, and cystatin and the lowest concentrations of proteins such as amylase were present in group B.

CCN3/NOV serum levels in coronary artery disease (CAD) patients and its correlation with TNF-α and IL-6.

INTRODUCTION: Dysregulation in the secretion of adipokines or adipocytokines plays a significant role in triggering a pro-inflammatory state, leading to endothelial dysfunction and insulin resistance, and ultimately elevating the risk of atherosclerosis and coronary artery disease (CAD). Previous studies have shown a link between NOV/CCN3 (an adipokine) and obesity, insulin resistance, and inflammation. However, no research has explored the relationship between CCN3 serum levels and CAD. Therefore, we conducted the first investigation to examine the correlation between CCN3 and CAD risk factors in patients. METHODS: In a case-control study, we measured the serum levels of CCN3, IL-6, adiponectin, and TNF-α in 88 angiography-confirmed CAD patients and 88 control individuals using ELISA kits. Additionally, we used an auto analyzer and commercial kits to measure the biochemical parameters. RESULTS: In patients with CAD, the serum levels of CCN3, TNF-α, and IL-6 were significantly higher compared to the control group, whereas lower levels of adiponectin were observed in the CAD group (P < 0.0001). A positive correlation was found between CCN3 and IL-6 and TNF-α in the CAD group ([r = 0.38, P < 0.0001], [r = 0.39, P < 0.0001], respectively). A binary logistic regression analysis showed the risk of CAD in the model adjusted (OR [95% CI] = 1.29 [1.19 - 1.41]), (P < 0.0001). We determined a cut-off value of CCN3 (3169.6 pg/mL) to distinguish CAD patients from the control group, with good sensitivity and specificity obtained for this finding (83.8% and 87.5%, respectively). CONCLUSION: This study provides evidence of a positive association between CCN3 serum levels and CAD, as well as inflammation markers such as IL-6 and TNF-α. These findings suggest that CCN3 may serve as a potential biomarker for CAD, and further investigations are necessary to validate this association and explore its potential use in clinical settings.

Color blindness defect and medical laboratory technologists: unnoticed problems and the care for screening.

Color-blindness is the inability to perceive differences between some color that other people can distinguish. Using a literature search, the results indicate the prevalence of color vision deficiency in the medical profession and its on medical skills. Medical laboratory technicians and technologists employees should also screen for color blindness. This research aimed to study color blindness prevalence among Hospitals' Clinical Laboratories' Employees and Students in Tehran University of Medical Sciences (TUMS). A cross-sectional descriptive and analytical study was conducted among 633 TUMS Clinical Laboratory Sciences' Students and Hospitals' Clinical Laboratories' Employees to detect color-blindness problems by Ishihara Test. The tests were first screened with certain pictures, then compared to the Ishihara criteria to be possible color defective were tested further with other plates to determine color - blindness defects. The data was saved using with SPSS software and analyzed by statistical methods. This is the first study to determine the prevalence of color - blindness in Clinical Laboratory Sciences' Students and Employees. 2.4% of TUMS Medical Laboratory Sciences Students and Hospitals' Clinical Laboratories' Employees are color-blind. There is significant correlation between color-blindness and sex and age. But the results showed that there is not significant correlation between color-blindness defect and exposure to chemical agents, type of job, trauma and surgery history, history of familial defect and race. It would be a wide range of difficulties by color blinded students and employees in their practice of laboratory diagnosis and techniques with a potentially of errors. We suggest color blindness as a medical conditions should restrict employment choices for medical laboratory technicians and technologists job in Iran.

Extracellular NAMPT/Visfatin induces proliferation through ERK1/2 and AKT and inhibits apoptosis in breast cancer cells.

BACKGROUND: Visfatin is a novel adipokine and proinflammatory cytokine which is implicated in breast cancer progression. The exact proliferative and anti-apoptotic mechanisms of visfatin are still under debate. In this study, the effect of extracellular visfatin on proliferation and apoptosis of breast cancer cells were investigated considering key regulatory molecules in these procedures. METHODS: BrdU (Bromodeoxyuridine) experiment was used to assess cell proliferation in response to visfatin treatment. Cell viability and apoptosis were assessed using MTT assay and flowcytometry, respectively. Phosphorylation levels of AKT and ERK1/2 as well as survivin levels and Poly ADP ribose polymerase (PARP) cleavage were investigated by western blot analysis. RESULTS: Visfatin induced proliferation of MCF-7 and MDA-MB-231 cells, an effect that was repressed by using AKT and ERK1/2 inhibitors, indicating involvement of these two signaling pathways in the proliferative effect of visfatin. Similarly, phosphorylation of AKT and ERK1/2 were elevated by visfatin treatment. On the other hand, visfatin improved cell viability and prevented TNF-α-induced apoptosis as well as PARP cleavage. Visfatin also exerted a protective effect on survivin. CONCLUSION: The results of this study suggest that visfatin induces breast cancer cell proliferation through AKT/PI3K and ERK/MAPK activation and protects against apoptosis in these cells. Thus increased visfatin levels may augment breast cancer development and attenuate treatment efficiency in breast cancer patients.

Enterolactone Reduces Telomerase Activity and The Level of Its Catalytic Subunit in Breast Cancer Cells.

OBJECTIVE: There is a positive correlation between higher serum phytoestrogen concentrations and lower risk of breast cancer. The activation of telomerase is crucial for the growth of cancer cells; therefore, the aim of this study was to examine the effects of enterolactone (ENL) and enterodiol (END) on this enzyme. MATERIALS AND METHODS: In this experimental study, we performed the viability assay to determine the effects of different concentrations of ENL and END on cell viability, and the effective concentrations of these two compounds on cell growth. We used western blot analysis to evaluate human telomerase reverse transcriptase catalytic subunit (hTERT) expression and polymerase chain reaction (PCR)-ELISA based on the telomeric repeat amplification protocol (TRAP) assay for telomerase activity. RESULTS: Both ENL and END, at 100 µM concentrations, significantly (P<0.05) reduced cell viability. However, only the 100 µM concentration of ENL significantly (P<0.05) decreased hTERT protein levels and telomerase activity. Lower concentrations of ENL did not have any significant effects on telomerase activity and hTERT protein levels. CONCLUSION: High concentration of ENL decreased the viability of MCF-7 breast cancer cells and inhibited the expression and activity of telomerase in these cells. Although END could reduce breast cancer cell viability, it did not have any effect on telomerase expression and activity.

Stepwise binding of nickel to horseradish peroxidase and inhibition of the enzymatic activity.

The incubation of horseradish peroxidase C (HRPC) with millimolar concentrations of nickel, at room temperature and at pH 4.0, induced the progressive formation of a metal-enzyme complex characterized by alterations of the enzyme Soret absorption band that were time- as well as nickel concentration- dependent. For any given incubation period between 1 and 60 min, 2 values for the apparent dissociation constant (K(d)) were found, suggesting the presence of binding sites with different affinities for nickel. The value of each K(d) dropped as the incubation time increased, indicating a progressive stabilization of the metal-enzyme complex. Hill plots suggested a cooperative binding of up to four Ni2+ ions per molecule of HRPC. The inhibition of the enzymatic activity by nickel was studied by following the H2O2-mediated oxidation of o-dianisidine by HRPC under steady-state kinetic conditions. Ni2+ was found to be either a noncompetitive or a mixed inhibitor of HRPC depending both on the duration of preincubation with the enzyme and on Ni2+ concentration. The enzyme remained active only over a limited metal concentration range and data indicated that binding of one Ni2+ affected the substrate binding site, binding of a second Ni2+ affected both substrate and peroxide binding sites, and binding of more than 2 Ni2+ per HRPC molecule led to complete loss of enzymatic activity. Results pointed to the damaging effects of prolonged exposure to heavy metals and also to the existence of a critical metal concentration beyond which immediate abolishing of enzymatic activity was observed.

Establishment of a prenatal diagnosis schedule as part of a prophylaxis program of factor XIII deficiency in the southeast of Iran.

Factor XIII deficiency (FXIIID) is an extremely rare bleeding disorder with a prevalence of 1 in 3 million in the general population. Compared to its global incidence, it has the greatest prevalence in Sistan and Baluchistan Province in the southeast of Iran. The high incidence of FXIIID in this region causes a high rate of morbidity and mortality among the affected individuals because of life-threatening episodes such as central nervous system (CNS) bleeding, umbilical cord bleeding, as well as miscarriage. CNS bleeding leads to a considerable number of neurological and behavioral complications. Therefore, we have designed an established prenatal diagnosis (PND) program to prevent the increasing incidence of life-threatening bleeding episodes and related complications among neonates with congenital FXIIID. This study was conducted from September 2013 to August 2014. A consent form was signed by the parents. Fetal sampling was done via abdominal chorionic villus sampling passage under local anesthesia and ultrasonic guidance within the first trimester of pregnancy. Fetal DNA was extracted, and PCR-restriction fragment length polymorphism was performed for the only reported mutation of FXIII (Trp187Arg) in the southeast of Iran. During the period of study, PND was performed on eight fetuses. Six fetuses were offspring of parental consanguineous marriages, and all of them had a positive family history of FXIIID. Seven out of the eight fetuses had a family member with CNS bleeding due to FXIIID. Four fetuses had a FXIIID-related death. One of the fetuses bore homozygous Trp187Arg mutation, whereas six were heterozygous, and one of the mothers gave birth to an unaffected fetus. To the best of our knowledge, PND is a possible solution to control high incidence of life-threatening episodes of FXIIID in southeast Iran.

Heterogeneous inhibition of horseradish peroxidase activity by cadmium.

Inhibition of horseradish peroxidase (HRP) activity by cadmium was studied under steady-state kinetic conditions after preincubation of the enzyme with millimolar concentrations of Cd(2+) for various periods of time. The H(2)O(2)-mediated oxidation of o-dianisidine by HRP was used to assess the enzymatic activity. Cd(2+) was found to be either a noncompetitive inhibitor of HRP or a mixed inhibitor of HRP depending both on the duration of incubation with HRP and on Cd(2+) concentration. Furthermore, for the same inhibition type, K(i) values dropped as incubation time increased. These results suggested that Cd(2+) would slowly bind to the enzyme and progressively induce conformational changes. Spectrophotometric analysis showed that indeed Cd(2+) altered the heme Soret absorption band on binding HRP and exhibited a K(d) which decreased as the incubation time of HRP with Cd(2+) increased. Hill plots suggested a cooperative binding of up to three Cd(2+) ions per molecule of HRP. Thus, Cd(2+) binding to HRP resulted in progressive inhibition of enzymatic activity with a change in the inhibition type as the number of Cd(2+) ions per HRP molecule increased. Results also illustrated the potential danger of long-term exposure to heavy metals, even for enzymes with low affinity for them.

Relationship between prooxidant-antioxidant balance and severity of coronary artery disease in patients of Imam Khomeini Hospital of Tehran, Iran.

The balance between reactive oxygen species production and antioxidant activity has an important role in oxidative stress associated diseases including coronary artery disease. In this study, the prooxidant-antioxidant balance (PAB) and its correlations with serum lipid levels, uric acid levels, and severity of coronary artery involvement were examined. The aim of this study was to determine the diagnostic value of PAB as a predictor in coronary artery disease (CAD). Seventy two patients and 68 healthy subjects were selected. PAB was determined using standard solutions and ELISA. Triglyceride, total cholesterol, LDL-cholesterol, HDL-cholesterol and uric acid levels were measured by enzymatic method. Mean PAB was 66.4 ± 2.84 (HK units) in healthy people, 77.37 ± 33.51 (HK units) in patients with one vessel CAD, 63.76 ± 29.47 (HK units) in patients with two vessel CAD and 68.59 ± 24.51 (HK units) in patients with three or more vessel CAD. There was no significant difference between PAB values in different severity groups (P=0.41). PAB significantly and indirectly correlated with uric acid level in two vessels CAD. The study shows that PAB can be a predictor of CAD associated with other risk factors, but not alone.

Effect of eicosapentaenoic acid on the expression of ABCG1 gene in the human monocyte THP-1 cells.

Cardiovascular disease (CVD) is the leading cause of death and disability in developed countries. Atherosclerosis is the major cause of CVD, accounting for about half of the attributed deaths. Cholesterol homeostasis is one of the most important factors in atherosclerosis. ATP-Binding cassette transporters cholesterol. Omega (ω) 3 fatty acids are important ligands for regulation of ABC transporters such as ABCG1. Concern has been raised that the low absolute intakes of EPA and high ratios of ω-6 polyunsaturated fatty acids (ω-6 PUFA) to EPA may predispose some individuals to CVD. Eicosapentaenoic acid (EPA) is the most abundant ω3 fatty acid in the diet. The objective of this study was to evaluate the effect of different concentrations of EPA on the expression of ABCG1 gene in the human monocyte THP-1 cells. In this study, THP-1 cells were cultured in RPMI 1640 medium, THP-1 monocytes were then differentiated to macrophages with PMA (phorbol myristic acid) and stimulated with 50, 75 and 100 µM of EPA for 24 h at 37°C. We examined the effects of EPA treatment on the expression of ABCG1 gene using Quantitative Real time RT-PCR (qRT-PCR). Our results, indicate that ABCG1 mRNA expression was significantly reduced by 50, 75 and 100 µM EPA fatty acid treatments as compared to the control cells (р = 0.009, р < 0.001 and р = 0.002, respectively). These results suggest that polyunsaturated fatty acids (PUFAs) such as EPA have an effect on the cholesterol homeostasis in macrophages, and they can change the expression of ABCG1 gene. It seems that EPA has different effects on gene expression and lipid metabolism.

Survey of serum procalcitonin in cirrhotic patients.

Procalcitonin (PCT) is a prohormone that has been used as a marker for the diagnosis of bacterial infections. The aim of this study was to survey PCT levels in patients with cirrhosis. Sixty-four patients with hepatic cirrhosis and 32 healthy blood donors were enrolled in this study. Serum PCT levels was detected using immunoluminometric assay. The rate of positive PCT was higher in patients with hepatitis C cirrhosis (92.8%) than the other groups. Among other cirrhotic patients, positive PCT levels were 77% for hepatitis B, 70% for cancer and 53.3% for unknown groups respectively. Serum procalcitonin levels were significantly higher in cirrhotic patients with bacterial infection (2.65±1.11 ng/ml) than those without infection (0.59±0.16 ng/ml, P=0.0001). PCT assay in cirrhotic patients may help diagnosis of sepsis and reduce unnecessary antibiotic use.

Significance of albumin and C-reactive protein variations in 300 end stage renal disease patients in Tehran University of Medical Sciences Hospitals during year 2010.

Protein- energy malnutrition, wasting and inflammation are frequent complication among patients with end-stage renal disease (ESRD). Malnutrition is associated with cardiac co-morbidity, inflammation and poor survival in ESRD patients. Serum albumin is a well-known marker of nutrition in ESRD patients. Serum albumin is still the most commonly used nutritional marker in ESRD patients. C-reactive protein (CRP), the major acute phase response (APR) protein is elevated in these patients. High CRP levels are linked to the degree of atherosclerosis in coronary, peripheral, and extracranial brain arteries. The aim of the present study was to investigate nutritional factor (albumin) and CRP levels in ESRD patients. In this cross- sectional study a total of 300 patients who had ESRD and had been on hemodialysis treatment for at least 6 months were selected. The laboratory tests consisted of measurement of CRP and albumin using high sensitive ELISA kits. The study patients included 157 males (52.3%) and 143 females (47.7%) with average age of 41.5 ± 14.3 years. Mean CRP level was 7.96 mg/ dl (±1.52), mean serum albumin was 4.07 g/dl (±0.19).Of 300 patients, 21 died (7%). These were patients with serum albumin <4 g/dl and CRP>9.5 mg/dl. This study showed that low albumin and high CRP levels are the main predictors for death. There was a significant difference between CRP and albumin levels in ESRD patients (P<0.0001). Measuring CRP as a marker of inflammation can be helpful in managing these patients.

Allele-specific oligonucleotide polymerase chain reaction for the determination of Rh C/c and Rh E/e antigens in thalassaemic patients.

BACKGROUND: Thalassaemia is a genetic disease in which there is a relative or complete lack of alpha or beta globin chains. Patients with moderate to severe forms of thalassaemia need transfusions from the early years of life. Antibody production against blood group antigens may cause many problems in preparing compatible blood units for transfusion. The identification of definite blood group phenotypes by the haemagglutination method can be difficult because of the mixed population of red blood cells from the donor and recipient. MATERIALS AND METHODS: Forty multiply transfused thalassaemic patients and ten healthy controls with no history of blood transfusion were enrolled in this study. Allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) and haemagglutination methods were used to determine the presence of Rhesus (Rh) C, c, E and e antigens. RESULTS: In this study four primer sets were used for ASO-PCR amplification of RhC/c and RhE/e. Although PCR assays for RhC/c and RHE/e genotyping have been described previously, in this study we used a new condition for PCR by decreasing the annealing temperature from 63 °C to 58 °C in order to amplify all four genes in the same condition. In order to evaluate this single run molecular method, we used the haemagglutination test as the standard method and compared the results from the two methods. We found discrepancies between phenotype and genotype results among patients with beta thalassaemia, but complete agreement between phenotype and genotype in the control group. CONCLUSIONS: The advantage of this new ASO-PCR method compared to a restriction fragment length polymorphism (RFLP) PCR method is that with the former all four genes can be amplified at the same time by PCR, and electrophoresis can be performed immediately to determine individual antigen profiles. The simplicity of the ASO-PCR method makes it suitable for routine use in medical centres and it is also cheaper than RFLP-PCR. Furthermore, as shown by previous studies, the results of haemagglutination and PCR tests often differ because the existence of donor red blood cells in the patient's circulation can interfere with the interpretation of the haemagglutination test.

Serum leptin concentrations during the menstrual cycle in Iranian healthy women.

Leptin, a circulating 16-kd polypeptide consisting of 167 amino acids, appears to be involved in the body weight homeostasis. Moreover leptin plays an important role for the reproductive system, early embryogenesis, and fat metabolism during pregnancy and puberty. Significant correlations have been found between leptin and sexual hormones, which is a cytokine and has hormonal properties. The aim of this study was to determine serum leptin levels during the menstrual cycle, and the association between serum leptin and reproductive hormones in young, healthy Iranian women. 42 healthy women volunteered for the study. They all had regular menstrual cycles, with cycle length varying between 26 and 32 days. None of them used oral contraceptives. All were of normal weight, with body mass index ( BMI) < 25 Kg/m2. Fasting blood samples were collected during the follicular phase, mid cycle and luteal phase of the menstrual cycle. FSH and LH were measured with coated tube immunoradiometric assay. Estrogen and progesterone were measured using antibody -coated tubes. Serum Leptin concentration were measured by Leptin (sandwich) ELISA. In menstruating women, serum leptin increased from 13.15+/-1.60 ng/ml in the early follicular phase to 16.57+/-1.68 ng/ml (P<0.01) at the luteal phase. Serum leptin concentration negatively correlated with LH and progesterone (P<0.05). Mean serum leptin levels correlated with body mass index (BMI) (r =0.78, P<0.001).