Serum Nitric Oxide Metabolite Levels Research Articles

Glyceryl trinitrate for the treatment of preterm labor.

This study was conducted to compare the tocolytic efficacy of glyceryltrinitrate (GTN) with that of magnesium sulfate (MgSO4) and to investigate serum nitric oxide metabolites before and after tocolysis. In total, 48 women between 27 and 34 weeks' gestation with threatened preterm labor and intact membranes were randomly allocated to receive either GTN or MgSO4 tocolysis. Main outcome measures included tocolytic efficacy and maternal side effect(s) of the tocolytic agent. Obstetric and neonatal outcomes as well as pretreatment and posttreatment nitric oxide (NO) metabolites were assessed. Forty-one patients were included into the final analysis. Uterine contraction cessation times were 3.66±1.28 and 6.83±3.47 hours for GTN and MgSO4 groups, respectively. Similarly, maternal side effects were significantly lower in the GTN group than in the MgSO4 group, and no serious maternal side effects were recorded. Serum NO metabolite levels before treatment were significantly lower in the treatment groups than in the controls. Serum nitrite levels were significantly increased after tocolytic treatment both in MgSO4 and GTN groups. GTN effectively delays preterm delivery and reduces neonatal morbidity and mortality with less maternal side effects and seems to be an effective and safe alternative to MgSO4.

Nitric oxide production, systemic inflammation and lipid metabolism in periodontitis patients: possible gender aspect

Nitric oxide (NO) plays a crucial role in vascular tone regulation and is involved in pathogenesis of periodontitis. In this cross-sectional study, we investigated the serum and saliva levels of NO metabolites in periodontal disease and their relationship with serum C-reactive protein (CRP) levels, lipids metabolism and periodontal disease severity. Serum and saliva were collected from non-smoking patients with generalized severe periodontitis (n = 89) and healthy controls (n = 56). Serum and salivary levels of NO metabolites, serum levels of high density lipoproteins (HDL), low density lipoproteins (LDL), triglycerides, cholesterol and CRP were measured. Data were analysed in whole population and in different gender groups. Periodontitis patients exhibited significantly lower serum and saliva levels of NO metabolites and significantly higher LDL, cholesterol and CRP levels than control group. Similar findings were observed within male but not within female population. Serum NO metabolites levels exhibited significant negative correlation with CRP in whole population and in male population. Significant positive correlation of serum NO metabolite levels with HDL levels was observed in whole population. NO production is reduced in periodontitis, especially in male population. Gender might be an important factor in assessing risk of cardiovascular disease in periodontitis.

Effect of nitrate and l-arginine therapy on nitric oxide levels in serum, heart, and aorta of fetal hypothyroid rats

Reduced nitric oxide availability and a heterogeneous pattern of nitric oxide synthase activity in some tissues have been reported in hypothyroidism. This study aimed at determining the effects of oral nitrate and L-arginine administration on serum, heart, and aorta nitric oxide metabolite concentrations in fetal hypothyroid rats. In an experimental study, pregnant Wistar rats were administrated tap water or 0.02 % of 6-propyl-2-thiouracil in drinking water during pregnancy and their male pups were followed (n = 8/group). In adult progeny, serum, heart, and aorta nitric oxide metabolite concentrations were measured by the Griess method after 1-week administration of sodium nitrate (500 mg/L) or L-arginine (2 %) in drinking water. Serum thyroid hormone and thyroid-stimulating hormone levels were also measured. Compared to controls, fetal hypothyroid progeny had significantly lower nitric oxide metabolite concentrations in heart (0.32 ± 0.07 vs. 0.90 ± 0.14 nmol/mg protein, p = 0.004) and aorta (2.98±0.56 vs. 6.15±0.74 nmol/mg protein, p = 0.011) tissues. Nitrate therapy restored heart nitric oxide metabolite levels decreased by fetal hypothyroidism, while L-arginine administration further decreased aorta nitric oxide metabolite levels. Sodium nitrate increased and L-arginine decreased serum nitric oxide metabolite levels in both control and fetal hypothyroid animals. In conclusion, nitrate therapy restores decreased heart nitric oxide metabolite levels, whereas L-arginine decreases aorta nitric oxide metabolite levels even further in fetal hypothyroid rats, findings relevant to the cardiovascular consequences of congenital hypothyroidism in adulthood.

Endotoxaemia in the pathogenesis of cytopenias in liver cirrhosis. Could oral antibiotics raise blood counts?

Cytopenias are frequently observed in patients with cirrhosis and are associated with increased morbidity. In particular, thrombocytopenia can impact routine care of patients with cirrhosis by potentially postponing or interfering with diagnostic and therapeutic procedures including liver biopsy and medically indicated or elective surgery. The pathogenesis of cytopenias in cirrhosis remains largely unknown. Historically, the concept of hypersplenism has long been associated with the cirrhosis-related hematological disorders but was never proven. On the other hand, intestinal bacterial overgrowth and altered gut permeability in cirrhotic patients lead to increased translocation of bacteria and endotoxin into the portal circulation. The impaired phagocytic function of the reticuloendothelial system together with the portosystemic shunting allow endotoxin to reach the systemic circulation and high concentrations of circulating endotoxin are found in cirrhotic patients even with no clinical evidence of infection and correlate with the severity of liver disease. Endotoxin activates monocytes and promotes the release of proinflammatory cytokines. Indeed, serum levels of interleukin-1, interleukin-6, tumor necrosis factor-α, and interferon-γ are elevated in patients with cirrhosis in proportion to the severity of liver disease. Endotoxaemia stimulates the vascular production of nitric oxide (NO) directly or indirectly via the cytokine cascade, and correlates with serum NO metabolite levels in cirrhosis. Several lines of evidence strongly suggest that endotoxaemia may reduce peripheral blood counts either directly or through the release of cytokines and NO. Previous studies in experimental models of cirrhosis and cirrhotic patients have demonstrated that long-term administration of oral antibiotics such as trimethoprim-sulfamethoxazole, norfloxacin, and rifaximin can reduce bacterial translocation and circulating levels of endotoxin, TNF-α, IL-6, and NO. We hypothesize that endotoxaemia plays a pivotal role in the pathogenesis of cytopenias in cirrhosis and that intestinal decontamination could raise peripheral blood counts by the suppression of endotoxaemia and the inhibition of cytokine and NO production.

Serum nitric oxide metabolite levels in a general healthy population: Relation to sex and age

This study aims at determining serum nitrite/nitrate (NO x) levels in healthy subjects within the framework of a population-based study. NO x concentration was measured in 3505 subjects aged ≥ 20 years. Subjects with diabetes, renal dysfunction, those undergoing treatment for dyslipidemia and hypertension, were excluded; also excluded were smokers, pregnant women, and subjects with cardiovascular and infectious diseases or cancer; leaving 1983 (667 men, 1316 women) asymptomatic non-smoking subjects for the analysis. NO x concentrations were determined in serum and compared in different age groups. Mean ± SE of NO x concentration was 24.8 ± 0.02 and 24.4 ± 0.01 µmol/l in men and women respectively. Men aged 20–29 years had significantly higher NO x levels compared to corresponding women (25.1 ± 0.03 vs. 22.7 ± 0.02). Serum NO x concentration peaked at 50–59 years in both genders. Comparison between lower and upper quartiles of NO x levels was performed in both genders. Women with high serum NO x were older and had significantly higher body mass index and fasting plasma glucose. The results of this study determine the normal levels of serum NO x concentrations in asymptomatic non-smoker subjects; also show that serum NO x concentrations indicate sex and age differences in these subjects.

Influence of ibuprofen-arginine on serum levels of nitric oxide metabolites in patients with chronic low back pain--a single-blind, placebo controlled pilot trial (ISRCTN18723747).

To determine whether ibuprofen-arginine has a cyclooxygenase-independent pain modulating property in addition to its known antiinflammatory effect. Patients with chronic low back pain were randomly divided into 2 groups treated either with oral ibuprofen-arginine (400 mg) or with placebo. Blood was drawn from study subjects before, during, and after treatment and they were asked each time about the intensity of their pain. Concentrations of nitric oxide (NO) metabolites were determined. Twenty minutes after intake of ibuprofen-arginine, but not after placebo, there was a relevant and significant reduction of NO metabolites in serum. In both groups there was significant analgesic effect compared to baseline. An early lowering of the serum NO metabolite levels after ibuprofen-arginine administration could be detected in patients with chronic low back pain.

The Significance of Serum Nitric Oxide Levels in Behçet's Disease and Recurrent Aphthous Stomatitis

Behçet's disease (BD) is an inflammatory multisystem disorder characterized by recurrent oral and genital aphthous ulcers, arthritis, uveitis, and thrombophlebitis; it can involve several organs. However, recurrent aphthous stomatitis (RAS) can be seen without a confirmed diagnosis of BD. Moreover, there is no way of predicting whether a patient with RAS will develop BD. Nitric oxide (NO) is a free radical synthesized from L-arginine by one of the family of nitric oxide synthase (NOS) enzymes. Increased production of NO during several inflammatory and infectious processes has been recently postulated. Our aim was to investigate the serum NO levels in patients with active and inactive BD and RAS. Forty-six patients with BD, 30 patients with RAS and 30 healthy controls were enrolled in the study. The patients with BD were separated into two groups: clinically active (n = 24) and inactive (n = 22). A blood sample was collected from all subjects in order to determine their serum NO levels. In patients with active BD, higher serum levels of NO metabolite were found in comparison with patients with inactive BD, in patients with RAS, or healthy controls (p < 0.05). We also found higher serum NO metabolite levels in patients with RAS than in healthy controls (p < 0.05). In patients with inactive BD, statistically significant higher levels of serum NO levels were found in comparison with the control group (p < 0.05). However, we found no statistically significant difference between the patients with inactive BD and RAS, which indicated that inactive BD cannot be distinguished from RAS by serum NO levels. We conclude that serum NO levels may be an important marker for estimating the severity of BD. However, further studies are needed to confirm our findings.

Serum nitric oxide metabolite levels and the effect of antipsychotic therapy in schizophrenia

Recently it was proposed that nitric oxide metabolites (NO) may have a role in the pathophysiology of schizophrenia and major depressive disorders. The present study was performed to assess changes in serum nitric oxide metabolite levels in schizophrenic patients compared with healthy controls. Our secondary aim was to further evaluate the impact of psychopharmacologic treatment on circulating NO levels not assessed previously. Serum NO levels of patients with schizophrenia (n=20) before and after 6 weeks of treatment were compared with those of healthy controls (n=20). Severity of schizophrenia and response to treatment were assessed with positive and negative symptoms of schizophrenia. NO levels were estimated by Griess method in serum samples. In patients with schizophrenia, pre-treatment serum NO levels were higher than those of control subjects (39.15 +/- 18.24 vs. 25.40 +/- 5.83 micromol/L, p=0.036) and also of post-treatment values (34.41 +/- 16.35 vs. 25.40 +/- 5.83 micromol/L, p=0.049), respectively. However, no significant difference was found between serum NO levels in pre- and post-treatment values. Our findings of increased serum NO levels in schizophrenic patients confirmed the role of NO in the pathophysiology of schizophrenia. However, we found that antipsychotic drugs do not reveal significant effects on serum levels of NO in schizophrenia in a 6-week treatment regimen. Further studies with longer therapy periods may suggest some new clues for novel treatment strategies employing antioxidants and NOS inhibitors in schizophrenia.