Diethylhexyl phthalate exposure amplifies oxidant and inflammatory response in fetal hyperglycemia model predisposing insulin resistance in zebrafish embryos

Exposure of zebrafish embryos to glucose is a suitable model for the fetal hyperglycemia seen in gestational diabetes. Diethylhexyl phthalate (DEHP), which is considered an endocrine-disrupting chemical, is one of the most common phthalate derivatives used in stretching plastic and is encountered in every area where plastic is used in daily life. In the present study, the effects of DEHP on pathways related to insulin resistance and obesity were examined in zebrafish embryos exposed to glucose as a fetal hyperglycemia model. Zebrafish embryos were exposed to DEHP, glucose, and glucose + DEHP for 72 h post-fertilization (hpf), and developmental parameters and locomotor activities were monitored. At 72 hpf ins, lepa, pparγ, atf4a, and il-6 expressions were determined by RT-PCR. Glucose, lipid peroxidation (LPO), nitric oxide (NO) levels, glutathione S-transferase (GST), superoxide dismutase (SOD), and acetylcholine esterase (AChE) activities were measured spectrophotometrically. Compared with the control group, glucose, LPO, GST activity, il6, and atf4a expressions increased in all exposure groups, while body length, locomotor, and SOD activities decreased. While AChE activity decreased in the DEHP and glucose groups, it increased in the glucose + DEHP group. Although glucose exposure increased pparγ and lepa expressions, DEHP significantly decreased the expressions of pparγ and lepa both in the DEHP and glucose + DEHP groups. Our findings showed that DEHP amplified oxidant and inflammatory responses in this fetal hyperglycemia model, predisposing insulin resistance in zebrafish embryos.

Gentisic acid exerts neuroprotective effects in neurotoxin-induced Parkinson's disease model in zebrafish: Cross-talk between pathways related with neurodegeneration in the gut-brain axis

Given that global prevalence of Parkinson's disease (PD) is expected to rise over the next few decades, understanding the mechanisms and causes of PD is critical. With emphasis on gut-brain axis, we sought to assess the impact of gentisic acid (GA), a diphenolic compound generated from benzoic acid, in rotenone (Rot) induced PD model in zebrafish. For thirty days, adult zebrafish were exposed to GA and rotenone. Tox-Track program was used to analyze locomotor behaviors in the control, GA, Rot, and Rot + GA groups. LC-MS/MS was performed in brain and intestinal tissues. Proteome Discoverer 2.4 was used to analyze raw files, peptide lists were searched against Danio rerio proteins. Protein interactions or annotations were obtained from STRING database. Tyrosine hydroxylase (Th) staining was performed immunohistochemically in the brain. PD-related gene expressions were determined by RT-PCR. Lipid peroxidation, nitric oxide, superoxide dismutase, glutathione S-transferase, and acetylcholinesterase were measured spectrophotometrically. Improved locomotor behaviors were observed by GA treatment in Rot group as evidenced by increased average speed, exploration rate, and total distance. 5214 proteins were identified in intestinal tissues, 4114 proteins were identified in brain by LC-MS/MS. Rotenone exposure altered protein expressions related to oxidative phosphorylation in brain and intestines. Protein expressions involved in ferroptis and actin cytoskeleton changed in brain and intestines. Altered protein expressions were improved by GA. GA ameliorated Th-immunoreactivity in brain, improved park2, park7, pink1, and lrrk2 expressions. Our results show that GA may be a candidate agent to be evaluated for its potential protective effect for PD.

Synthesis of salicylic acid from wintergreen oil by green chemistry overcomes its cytotoxicity in keratinocyte cells and teratogenicity in zebrafish embryos

Salicylic acid topical is used to treat variety of skin conditions. However, salicylic acid in these products is generated through industrial synthesis and has been shown to negatively impact fetal development and cause congenital abnormalities. We hypothesized that teratogenic effects reported in salicylic acid can be prevented by naturally synthesizing salicylic acid from wintergreen oil using green chemistry method. For this purpose, we investigated the effects of natural salicylic acid (NSA) synthesized from wintergreen oil using green chemistry and synthetic salicylic acid (SSA) on keratinocyte cell (HaCaT) proliferation and zebrafish embryo development. NSA structures were analyzed by 1H NMR, 13C NMR, and GC/MS methods. Percentage inhibition against HaCaT cell was determined by MTS assay. xCelligence system was used for cellular activities. Zebrafish embryos were exposed to NSA and SSA for 72 h post-fertilization. Lipid peroxidation, nitric oxide, sialic acid, glutathione-S-transferase, catalase, and superoxide dismutase were evaluated using biochemical methods. Expressions of nqO1, gfap, bdnf, vtg, egr, cyp1a, and igf2 were determined by RT-PCR as developmental indicators. MTS and RT-cell analysis showed increased cell viability by NSA, whereas SSA decreased cell viability. NSA beneficially affected zebrafish embryo development while SSA exerted deleterious effects through oxidant-antioxidant status, inflammation, and development. Results of our study showed for the first time that synthesis of salicylic acid from wintergreen oil by green chemistry overcomes its cytotoxicity in keratinocyte cells and teratogenicity in zebrafish embryos. This finding is important for drug research on safe topical applications during pregnancy, when preventing exposure to drug and chemical-derived teratogens is vital.

Whole-Mount RNA In Situ Hybridization of Zebrafish Embryos

A commonly employed technique in molecular biology to evaluate the temporal and spatial expression of a certain gene is in situ hybridization. This method is an effective strategy to construct synexpression groups, co-expressed genes acting in shared biological processes, and to find new members of genes engaged in the same signaling pathways to discover similar spatial and temporal expression patterns in zebrafish embryos. The major disadvantage of this method is that RNA probes can penetrate within 2 days of post-fertilization embryos, and therefore, in later developmental stages, the probe can only reach the surface tissues. Further application of the method in histological sections will be required for a complete and accurate gene expression investigation. However, this method is highly effective at late embryogenesis and early larval stages for observing gene expression in endodermal derivatives and sensory organs. RNA probes for in situ hybridization can be prepared through in vitro transcription from plasmids carrying specific promoter elements and mRNA-specific cDNA, or an alternative polymerase chain reaction (PCR) method can be used through PCR amplification. This chapter describes the procedures for detecting gene expression in zebrafish embryos using whole-mount RNA in situ hybridization.

Morphine ameliorates pentylenetetrazole-induced locomotor pattern in zebrafish embryos; mechanism involving regulation of opioid receptors, suppression of oxidative stress, and inflammation in epileptogenesis

Zebrafish (Danio rerio) is becoming an increasingly important model in epilepsy research. Pentylenetetrazole (PTZ) is a convulsant agent that induces epileptic seizure-like state in zebrafish and zebrafish embryos and is most commonly used in antiepileptic drug discovery research to evaluate seizure mechanisms. Classical antiepileptic drugs, such as valproic acid (VPA) reduce PTZ-induced epileptiform activities. Opioid system has been suggested to play a role in epileptogenesis. The aim of our study is to determine the effects of morphine in PTZ-induced epilepsy model in zebrafish embryos by evaluating locomotor activity and parameters related to oxidant-antioxidant status, inflammation, and cholinergic system as well as markers of neuronal activity c-fos, bdnf, and opioid receptors. Zebrafish embryos at 72 hpf were exposed to PTZ (20 mM), VPA (1 mM), and Morphine (MOR) (100 µM). MOR and VPA pretreated groups were treated with either MOR (MOR + PTZ) or VPA (VPA + PTZ) for 20 min before PTZ expoure. Locomotor activity was quantified as total distance moved (mm), average speed (mm/sec) and exploration rate (%) and analyzed using ToxTrac tracking programme. Oxidant-antioxidant system parameters, acetylcholinesterase activity, and sialic acid leves were evaluated using spectrophotometric methods. The expression of c-fos, bdnf, oprm1, and oprd1 were evaluated by RT-PCR. MOR pretreatment ameliorated PTZ-induced locomotor pattern as evidenced by improved average speed, exploration rate and distance traveled. We report the restoration of inflammatory and oxidant-antioxidant system parameters, c-fos, bdnf, and opioid receptor oprm1 as the possible mechanisms involved in the ameliorative effect of MOR against PTZ-induced epileptogenic process in zebrafish embryos.

Identification of molecular network of gut-brain axis associated with neuroprotective effects of PPARδ-ligand erucic acid in rotenone-induced Parkinson's disease model in zebrafish

Disruption of the gut-brain axis in Parkinson's disease (PD) may lead to motor symptoms and PD pathogenesis. Recently, the neuroprotective potential of different PPARδ-agonists has been shown. We aimed to reveal the effects of erucic acid, peroxisome proliferator-activated receptors (PPARs)-ligand in rotenone-induced PD model in zebrafish, focusing on the gut-brain axis. Adult zebrafish were exposed to rotenone and erucic acid for 30 days. Liquid chromatography-mass spectrometry and tandem mass spectrometry (LC-MS/MS) analysis was performed. Raw files were analysed by Proteome Discoverer 2.4 software; peptide lists were searched against Danio rerio proteins. STRING database was used for protein annotations or interactions. Lipid peroxidation (LPO), nitric oxide (No), alkaline phosphatase, superoxide dismutase, glutathione S-transferase (GST), acetylcholinesterase and the expressions of PD-related genes were determined. Immunohistochemical tyrosine hydroxylase (TH) staining was performed. LC-MS/MS analyses allowed identification of over 2000 proteins in each sample. The 2502 and 2707 proteins overlapped for intestine and brain. The 196 and 243 significantly dysregulated proteins in the brain and intestines were found in rotenone groups. Erucic acid treatment corrected the changes in the expression of proteins associated with cytoskeletal organisation, transport and localisation and improved locomotor activity, expressions of TH, PD-related genes (lrrk2, park2, park7, pink1) and oxidant-damage in brain and intestines in the rotenone group as evidenced by decreased LPO, No and increased GST. Our results showed beneficial effects of erucic acid as a PPARδ-ligand in neurotoxin-induced PD model in zebrafish. We believe that our study will shed light on the mechanism of the effects of PPARδ agonists and ω9-fatty acids in the gut-brain axis of PD.

The emerging relationship between vitamin K and neurodegenerative diseases: a review of current evidence

Neurodegenerative disease refers to a group of disorders that predominantly damage the neurons in the brain. Despite significant progress in the knowledge of neurodegenerative diseases, there is currently no disease-modifying drug available. Vitamin K was first established for its involvement in blood clotting, but there is now compelling evidence indicating its role in the neurological system. In particular, the results of recent studies on the effects of vitamin K2 on preventing apoptosis, oxidative stress, and microglial activation in neuron cells through its role in electron transport are very promising against Alzheimer's disease. In addition to its protective effect on cognitive functions, its inhibitory effects on inflammation and α-synuclein fibrillization in Parkinson's disease, which has been revealed in recent years, are remarkable. Although there are many studies on the mechanism and possible treatment methods of neurodegenerative diseases, especially Parkinson's and Alzheimer's disease, studies on the relationship between vitamin K and neurodegenerative diseases are very limited, yet have promising findings. Vitamin K has also been proposed for therapeutic use in multiple sclerosis patients to lower the intensity or to slow down the progression of the disease. Accordingly, the aim of this study is to review the current evidence for the use of vitamin K supplementation in neurodegenerative diseases, in particular Alzheimer's disease, Parkinson's disease, and multiple sclerosis.

Bisphenol A reveals its obesogenic effects through disrupting glucose tolerance, oxidant-antioxidant balance, and modulating inflammatory cytokines and fibroblast growth factor in zebrafish

Obesogens affect lipid metabolism, and genetic or epigenetic factors may also contribute to the progression of obesity. Endocrine-disrupting chemicals (EDCs) are the most striking among obesogens. Bisphenol A (BPA) is an estrogenic EDC used in food containers, adhesives, dye powders, and dental fillers. We aimed to elucidate molecular mechanisms of BPA's obesogenic effects focusing on obesogenic pathways in the liver including fibroblast growth factor (FGF) and Dnmt3a which is its epigenetic regulator, oxidant-antioxidant status, and inflammatory cytokines. Zebrafish were divided into three groups as control, low-dose BPA (1 μm BPA), and high-dose BPA groups (10 μm BPA). At the end of 30 days, oral glucose tolerance test (OGTT) was performed, fasting blood glucose levels were measured, and hepatopancreas tissues were taken. Malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione S-transferase (GST), and nitric oxide (NO) activities were examined in the hepatopancreas. Inflammatory cytokines, lepa, fgf21, and dnmt3a expressions were determined by RT-PCR. BPA exposure increased the body weights, il1ß, tnfα, il6, lepa, fgf21, and dnmt3a expressions, impaired glucose tolerance, and oxidant-antioxidant status in a dose-dependent manner. Hepatocyte degeneration, lipid vacuolization, and vasocongestion were observed in both BPA-exposed groups. Our study suggests impaired glucose tolerance, oxidant-antioxidant balance, increased inflammatory response, fgf21 expression, and dnmt3a expressions as the possible mechanisms for the BPA-induced obesity model in zebrafish.

Morphine attenuates neurotoxic effects of MPTP in zebrafish embryos by regulating oxidant/antioxidant balance and acetylcholinesterase activity

Parkinson's disease (PD) is one of the most common neurodegenerative diseases due to the loss of dopaminergic neurons in the midbrain in the substantia nigra. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxic agent causing disruptions in mitochondria of dopaminergic neurons leading to impaired oxidant-antioxidant balance. Both zebrafish and zebrafish embryos are sensitive to MPTP. In zebrafish embryos, MPTP decreases the dopaminergic cells in the diencephalon by damaging dopaminergic neurons. Morphine is an opioid pain killer and a strong analgesic that is used to treat chronic pain. Until today morphine has been shown to regulate the survival or death of neurons and both protective and destructive effects of morphine have been reported in the central nervous system. This study aimed to evaluate the effects of morphine in MPTP-exposed zebrafish embryos. Developmental parameters were monitored and documented daily during embryonic development. Locomotor activity of zebrafish embryos at 96 h postfertilization (hpf) was determined. Acetylcholinesterase (AChE) activity and oxidant-antioxidant parameters were analyzed by biochemical methods. RT-PCR was used to evaluate bdnf, dj1, lrrk and pink1 expressions. Morphine treatment improved mortality and hatching rates, locomotor activity, AChE, and antioxidant enzyme activities as well as the expressions of bdnf, dj1, lrrk and pink1 in a dose-dependent manner that were altered by MPTP. Increased lipid peroxidation supports the role of morphine to induce autophagy to prevent PD-related pathologies. Our study provided important data on the possible molecular mechanism of the therapeutic effects of morphine in PD.

3-Pyridinylboronic acid normalizes the effects of 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine exposure in zebrafish embryos

1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a neurotoxin that damages dopaminergic neurons. Zebrafish has been shown to be a suitable model organism to investigate the molecular pathways in the pathogenesis of Parkinson's disease and also for potential therapeutic agent research. Boron has been shown to play an important role in the neural activity of the brain. Boronic acids are used in combinatorial approaches in drug design and discovery. The effect of 3-pyridinylboronic acid which is an important sub-class of heterocyclic boronic acids has not been evaluated in case of MPTP exposure in zebrafish embryos. Accordingly, this study was designed to investigate the effects of 3-pyridinylboronic acid on MPTP exposed zebrafish embryos focusing on the molecular pathways related to neurodegeneration and apoptosis by RT-PCR. Zebrafish embryos were exposed to MPTP (800 μM); MPTP + Low Dose 3-Pyridinylboronic acid (50 μM) (MPTP + LB) and MPTP + High Dose 3-Pyridinylboronic acid (100 μM) (MPTP + HB) in well plates for 72 hours post fertilization. Results of our study showed that MPTP induced a P53 dependent and Bax mediated apoptosis in zebrafish embryos and 3-pyridinylboronic acid restored the locomotor activity and gene expressions related to mitochondrial dysfunction and oxidative stress due to the deleterious effects of MPTP, in a dose-dependent manner.

Methylnitrosourea, dimethylbenzanthracene and benzoapyrene differentially affect redox pathways, apoptosis and immunity in zebrafish

Cancer continues to be a major cause of mortality globally. Zebrafish present suitable models for studying the mechanisms of genotoxic carcinogens. The aim of this study was to investigate the interaction between oxidant-antioxidant status, apoptosis and immunity in zebrafish that were exposed to three different genotoxic carcinogens methylnitrosourea, dimethylbenzanthracene, benzoapyrene and methylnitrosourea + dimethylbenzanthracene starting from early embryogenesis for 30 days. Lipid peroxidation, nitric oxide levels, superoxide dismutase and glutathione-S-transferase activities and mRNA levels of apoptosis genes p53, bax, casp3a, casp2 and immunity genes fas, tnfα and ifnγ1 were evaluated. The disruption of the oxidant-antioxidant balance accompanied by altered expressions of apoptotic and immunity related genes were observed in different levels according to the carcinogen applied. Noteworthy, ifnγ expressions decreased in all carcinogen-exposed groups. Our results will provide basic data for further carcinogenesis research in zebrafish models.

Bisphenol A and di(2-ethylhexyl) phthalate exert divergent effects on apoptosis and the Wnt/β-catenin pathway in zebrafish embryos: A possible mechanism of endocrine disrupting chemical action

Polyethylene terephthalate (PET) and polycarbonate (PC) are the most commonly used plastics in water bottles. Di(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer in PET plastics, and bisphenol A (BPA) is used to produce PC. Both DEHP and BPA are known for their potential endocrine disrupting effects. The Wnt/β-catenin signaling pathway has important roles in cell proliferation, cell specification and cell fate determination during embryonic development. Recent reports suggest a link between the Wnt/β-catenin signaling pathway and apoptosis. The aim of this study was to investigate the relation between Wnt/β-catenin signaling and apoptosis in the case of BPA and DEHP exposure in zebrafish embryos. Accordingly, in vivo cell death was assessed using acridine orange staining, and reverse transcription polymerase chain reaction was used to determine the expressions of wnt3a, gsk3β and ccnd1. Proliferative cell nuclear antigen, β-catenin and Wnt3a expressions were determined immunohistochemically. Vitellogenin levels were determined using Enzyme Linked ImmunoSorbent Assay (ELISA). Increased vitellogenin levels, apoptosis, and wnt3a and gsk3β expressions were observed in BPA-exposed zebrafish embryos. Increased apoptosis in the BPA-exposed embryos may be due to the pro-apoptotic changes induced by Wnt3a, whereas DEHP might be suggested to have a minor effect as Wnt3a expression; vitellogenin levels and apoptosis did not increase significantly following exposure to DEHP.

Galectin-3 and plasma cytokines in patients with acute myocardial infarction

OBJECTIVE

To investigate the concentrations of plasma cytokines and Galectin-3 (Gal-3) as inflammatory markers in patients with acute myocardial infarction (AMI).

METHODS

The study population consisted of 29 patients with AMI and 29 healthy control subjects. We measured Gal-3, tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6) levels in plasma using enzyme-linked immunosorbent assays (ELISAs). We measured levels of C-reactive protein (CRP) via the nephelometric method.

RESULTS

Patients with AMI showed significantly higher plasma Gal-3, TNF-α, and IL-6 levels compared with controls. Gal-3 levels were positively and significantly correlated with plasma IL-6, TNF-α, and CRP levels in the control and patient groups.

CONCLUSION

Our findings suggest that Gal-3 can be a new circulating biomarker of inflammation associated with AMI.

Determination of oxidant stress in plasma of rheumatoid arthritis and primary osteoarthritis patients

Determination of oxidant stress in plasma of rheumatoid arthritis (RA) and primary osteoarthritis (POA) patients is important in understanding the pathogenesis of these diseases. In this study, we examined the relationship between oxidant stress and inflammation by measuring protein carbonyl content, thiol levels and plasma protein fractions as the oxidation markers and erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) tests as inflammation markers. Protein carbonyls content was higher in RA and POA patients, as compared to controls (p<0.0001), while the plasma thiol levels in both groups of patients were significantly lower than controls (p<0.0001). Increased levels of proteins under 40 kDa molecular mass were detected in the RA and POA patients compared to that of controls (p<0.0001) both in HPLC and SDS-PAGE analysis. Total protein concentration in plasma of RA patients was higher than the controls (p<0.001), while in POA patients was lower than that of controls (p<0.001). ESR and CRP levels were higher in both the patient groups than the normal group (p<0.001). These results suggested that alterations in the oxidant stress markers could be the cause of inflammation in these diseases. Thus, while working for RA/POA treatment strategies, consideration of the relationship between oxidant stress and inflammation would be worth evaluating.

Effect of sample storage on stability of salivary glutathione, lipid peroxidation levels, and tissue factor activity

Saliva samples are often required to be stored for longer periods of time either because of the project protocol or because of lack of funding for analysis. The effects of 6 months storage (fresh, 30, 60, 90 120, 150, and 180 d) on the stability of salivary reduced glutathione (GSH), lipid peroxidation (LPO) and 90 days of storage (fresh, 15, 30, 60, and 90 d) on the stability of salivary tissue factor (TF) activity and the stability of saliva imprint samples at -20 degrees C were evaluated in this study. Salivary GSH, malondialdehyde (MDA) levels as an index of LPO, and TF activities were determined using the methods of Beutler, Yagi, and Quick, respectively. Saliva imprint samples were stained with Giemsa and microscopically examined. Salivary GSH levels and TF activities decreased, whereas MDA levels increased significantly after 6 months of storage at -20 degrees C. Leucocyte, epithelium and bacterium cell counts did not significantly change at the end of 90 d of storage. Saliva samples may be stored up to 1 month at -20 degrees C for LPO assay. For cytological examinations, saliva samples may be stored for 90 d at -20 degrees C. Further studies are needed to determine the stability of salivary GSH, and salivary TF activity stored less than 30 days at -20 degrees C. On the other hand, if saliva samples are required to be stored, to avoid the changes because of different storage periods, we recommend that they must be stored under the same circumstances and in the same time period.

Consumption of pistachio nuts beneficially affected blood lipids and total antioxidant activity in rats fed a high-cholesterol diet

Although nuts are typically high in dietary fat, novel studies have shown that regular consumption of these heart-healthy foods might confer a beneficial effect on cardiovascular disease risk. In the present study, we aimed to analyse the effects of pistachio consumption on blood lipids, antioxidant activity, oxidative stress and sialic acid levels in high-fat-fed rats for 8 weeks. The oxidant-antioxidant status was evaluated by the determination of lipid peroxidation (thiobarbituric acid-reactive substances), total antioxidant activity, reduced glutathione content, activity of superoxide dismutase and total thiol levels. Furthermore, tissue damage was evaluated by total sialic acid levels in serum. Total cholesterol, triglycerides, sialic acid and thiobarbituric acid-reactive substances significantly increased whereas total antioxidant activity, reduced glutathione, total thiol levels significantly decreased in the hyperlipidaemic group compared to the control group. Pistachio consumption significantly decreased triglycerides and thiobarbituric acid-reactive substance levels and significantly increased total antioxidant activity in the hyperlipidaemic group. In conclusion, pistachio supplementation may improve blood lipids and ameliorate oxidative stress in experimental hyperlipidaemia, which may have beneficial applications in the prevention of cardiovascular diseases. However, its antioxidant mechanisms remain to be investigated.

Investigation of zinc and copper levels in methimazole-induced hypothyroidism: relation with the oxidant-antioxidant status

Thyroid hormones are associated with the oxidative and antioxidative status of the organism. Depression of metabolism by hypothyroidism has been reported to decrease oxidant production and thus protect tissues against oxidant damage. The purpose of the present study was to investigate Zn and Cu levels in MMI-induced hypothyroidism and to show whether there is a connection between these trace elements and the oxidant-antioxidant status in experimental hypothyroidism. 3-Nitrotyrosine was measured as a marker of nitro-oxidative stress. In order to examine the antioxidant status of MMI-induced hypothyroidism in rats, GSH and SOD levels were determined as well. Significantly decreased 3-nitrotyrosine, Cu and Zn levels were observed in our experimental model when compared with the controls. On the other hand, GSH and SOD levels remained constant. It may be suggested that Cu and Zn serve as antioxidant molecules and exert their effects in an indirect manner to reduce oxidative stress in experimental hypothyroidism.

Investigation of tissue factor and other hemostatic profiles in experimental hypothyroidism

The influence of thyroid failure on hemostasis has been studied and is still not well understood. These patients have high risk for cardiovascular diseases because of the lipid metabolism and procoagulant agents. But the influence of thyroid failure on hemostasis is controversial. Tissue factor (TF) has an important role in the thromboembolic state. Recent experiments have demonstrated that TF-dependent activation of the coagulation cascade plays an important role in the pathophysiology of intravascular thrombus formation. The purpose of the present study was to investigate the contributions of TF, factor VII:C (FVII:C), factor XII:C (FXII:C), and fibrinogen in experimental hypothyroidism. TF was obtained from the thyroid gland and lung tissue of 10 rats following experimental hypothyroidism induced for 30 d and compared with similar tissue from 10 control rats. Significantly increased TF activities were found in hypothyroid rats. By contrast, FVII:C level was significantly decreased when compared with the control group. In this respect it is interesting to note that a hypercoagulable state due to increased thromboplastic activity may occur. Based on those results, elevated tissue factor activities (TFa) of the patients with low thyroid dysfunction may have another risk factor for cardiovascular diseases.

Lipid peroxidation, erythrocyte superoxide-dismutase activity and trace metals in young male footballers

Physical training is known to induce oxidative stress in individuals subjected to intense exercise. In this study, we investigated plasma malondialdehyde (MDA) levels and erythrocyte superoxide dismutase (SOD) activity of 25 young male footballers and a control group of similar age. Red blood cell (RBC) count, haemoglobin (Hb) and haematocrit (Hct) values, and copper (Cu) and zinc (Zn) levels were also examined. The maximal oxygen uptake (VO2max) of all subjects was determined in order to establish their functional capacity. The main finding of the present study was that plasma MDA levels, one of the most commonly used markers of lipid peroxidation, of this group of footballers aged under 21 decreased slightly when compared with those of the control group (p < 0.001). In contrast, erythrocyte SOD activity was higher in the footballer group than in the controls (p < 0.001). Footballers who are under regular training showed an improved antioxidant activity in comparison to sedentary controls. Plasma copper concentration, RBC count and Hb concentration of the footballer group were all significantly lower than those of the control group, (p < 0.001, p < 0.01, p < 0.01, respectively). Investigating the footballers' data with Spearman's correlation analyses, the correlation coefficients (r) between Zn/Cu ratio and SOD was positive (r=0.44; p < 0.05); and between VO2max and SOD (r=0.42; p < 0.05) were both positive. On the basis of statistical analysis, we suggest that regular exercise may be beneficial in cases of oxidative damage by reducing the amount of lipid peroxidation and increasing the activity of the antioxidant enzyme SOD.