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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Natural variation in abiotic factors, such as temperature and pH, probably influence the activity of enzymes used as potential biomarkers in bivalve mollusks to assess environmental contamination in the field. Changes in levels of an enzymatic biomarker may thus merely reflect natural variation in the annual physiological cycle of a species rather than exposure to contaminants. To investigate this issue, we documented the relationship between pesticide levels in water and three different enzymatic biomarkers over 1 year in enclosed populations of the freshwater unionid mussel Anodonta cygnea at three different sites of exposure. We considered the natural variation in temperature, pH and dissolved oxygen over the year and across the different sites as a potential correlate of enzymatic activity to disentangle the relative contribution of abiotic factors and pesticide levels. Pesticide levels varied among the three sites and over the course of the year. Catalase (CAT) and acetylcholinesterase activity (AChE) varied as a function of abiotic factors but showed no relation to pesticide levels. Glutathione S-transferase (GST) activity was also related to abiotic factors but also decreased with increases in total pesticide levels. The lack of activity induction or inhibition by pesticides and the natural variation in abiotic factors among sites and across time limits the use of CAT and AChE to assess environmental contamination in this species.
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PMID:The role of abiotic factors and pesticide levels on enzymatic activity in the freshwater mussel Anodonta cygnea at three different exposure sites. 1278 40

A battery of biochemical parameters was used to evaluate the response of mussels to a contaminated coastal environment. A multimarker approach was developed, establishing a scale for the classification of the water quality in European coastal sites (BIOMAR European programme). This study allows the evaluation of the temporal trends of this scale when applied to selected sites of European Mediterranean coast (BEEP Biological Effects of Environmental Pollution in Marine Coastal Ecosystems: European programme). Acetylcholinesterase activity (AChE) is highly sensitive to organophosphorus and carbamate insecticides and, to some extent, also to heavy metals. Catalase activity (CAT) and lipid oxidation (evaluated as malonedialdehyde) are markers of oxidative stress, glutathione S-transferase (GST) activity is related to conjugation of organic compounds and benzo(a)pyrene hydroxylase activity (BPH) is a marker of effect of certain planar organic compounds (e.g. polycyclic aromatic hydrocarbons, PAHs). These parameters were measured either in gills (AChE, GST) or digestive gland (BPH, GST, CAT, MDA). For each biomarker, a discriminatory factor was calculated (maximum variation range/confidence interval) and a response index was allocated. For each site, a Multimarker Pollution Index (MPI) was calculated as the sum of the response index of each of the five more discriminating biomarkers. As the result of our calculation method, the quality of the coastal environment at each site can be classified according to a five levels scale. Samples collected for five cruises in May 2001, 2002, 2003, and September 2001 and 2002 showed MPI evolutions. The results show that water quality can be classified from class 1 (clean areas in some sites of France, Italy and Spain) to class 4 (high pollution in main harbours). Results of the use of the biomarker scale in WP3 (Work Package Concernant Biomonitoring Programmes in Mediterranean Sea) during the BEEP programme make a strong contribution to the establishment of standardized strategies and methods for internationally agreed protocols for biomarker-based monitoring programmes. In comparison with scale pollution methodology used in the BIOMAR programme, the main contribution of BEEP was (1) to select from discriminatory analysis the biomarkers to be included in calculation of scale pollution; (2) to improve the use of the biomarker index in order to identify the main contaminants by analysis of individual contributions to the MPI; and (3) to apply methodology for temporal trends at sampled sites.
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PMID:Scale of classification based on biochemical markers in mussels: application to pollution monitoring in Mediterranean coasts and temporal trends. 1609 93

Spatial memory is coordinated with different brain regions especially hippocampus (HIP) and medial prefrontal cortex (mPFC). Influence of noise stress on working and reference memory error in rats was evaluated by radial eight-arm maze experiment. Changes in the dendritic count were observed in the brain regions such as CA1, CA3 regions of HIP and layers II, III of mPFC. In order to understand the possible mechanism behind noise stress-induced changes, free radical status and acetylcholinesterase (AChE) activity in HIP and mPFC were evaluated. Plasma corticosterone level was also evaluated. Results obtained in this study showed that after noise-stress exposure, 100 dBA/4h per day for 30 days, working and reference memory error increased significantly (P < 0.05) when compared to control animals. Neuronal dendritic count in the HIP was reduced in the 2nd and 3rd order dendrites but not in the mPFC. Superoxide dismutase, lipid peroxidation, plasma corticosterone level and AChE activity were significantly increased in the 1 day, 15 days and 30 days stress groups animal significantly. Catalase and glutathione peroxidase activity were increased in the 1 day and 15 days noise-stress groups but decreased in the 30 days noise-stress group and GSH level was decreased in all the stress exposed animals. In conclusion, oxidative stress, increased AChE activity, reduced dendritic count in HIP, mPFC regions and elevated plasma corticosterone level which develops in long-term noise-stress exposed rats, might have caused the impairment of spatial memory.
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PMID:Effects of chronic noise stress on spatial memory of rats in relation to neuronal dendritic alteration and free radical-imbalance in hippocampus and medial prefrontal cortex. 1648 Nov 10

Microdialysis has been widely used to measure acetylcholine (ACh) release in vivo and has provided important insights into the regulation of cholinergic transmission. However, microdialysis can be constrained by limited spatial and temporal resolution. The present experiments utilize a microelectrode array (MEA) to rapidly measure ACh release and clearance in anaesthetized rats. The array electrochemically detects, on a second-by-second basis, changes in current selectively produced by the hydrolysis of ACh to choline (Ch) and the subsequent oxidation of choline and hydrogen peroxidase (H(2)O(2)) at the electrode surface. In vitro calibration of the microelectrode revealed linear responses to ACh (R(2) = 0.9998), limit of detection of 0.08 microm, and signal-to-noise ratio of 3.0. The electrode was unresponsive to ascorbic acid (AA), dopamine (DA), or norepinephrine (NE) interferents. In vivo experiments were conducted in prefrontal cortex (PFC) of anaesthetized rats. Pressure ejections of ACh (10 mm; 40 nL) through an adjoining micropipette produced a rapid rise in current, reaching maximum amplitude in approximately 1.0 s and cleared by 80% within 4-11 s. Endogenously released ACh, following local depolarization with KCl (70 mm; 40, 160 nL), was detected at values as low as 0.05 microm. These signals were volume-dependent and cleared within 4-12 s. Finally, nicotine (1.0 mm, 80 nL) stimulated ACh signals. Nicotine-induced signals reflected the hydrolysis of ACh by endogenous acetylcholinesterase (AChE) as inhibition of the enzyme following perfusion with neostigmine (10 microm) attenuated the signal (40-94%). Collectively, these data validate a novel method for rapidly measuring cholinergic transmission in vivo with a spatial and temporal resolution that far exceeds conventional microdialysis.
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PMID:Second-by-second measurement of acetylcholine release in prefrontal cortex. 1715 1

The effects of the herbicide, clomazone, on acetylcholinesterase (AChE), catalase and TBARS formation in teleost fish (Rhamdia quelen) were studied. The fish were exposed to 0.5 or 1.0 mg L(-1) of clomazone for 12, 24, 48, 96 and 192 h. After 192 h of exposure period, fish were transferred to clean water and kept in the same for 192 h to study the recovery response. Same parameters as that of exposure period were assayed after 96 and 192 h of recovery period. Specific AChE activity was reduced in the brain and muscle after treatments, reaching a maximum inhibition of 47% in the brain and 45% in the muscle after 12h of exposure. Fish exposed to clomazone increased TBARS production in the liver for all exposure periods. The brain presented elevated TBARS levels after 12, 24 and 48 h, but after 96 and 192 h, these levels decreased. The decrease of TBARS levels persisted in brain tissue after 96 h of recovery and returned to the control value after 192 h in clean water. Catalase activity was reduced for all periods of exposure. Histological analysis showed vacuolation in the liver after herbicide exposure. Some of the alterations observed were completely restored after recovery period.
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PMID:Effect of clomazone herbicide on biochemical and histological aspects of silver catfish (Rhamdia quelen) and recovery pattern. 1728 Jul 6

Blue mussels (Mytilus edulis) were exposed to an extract made of natural cyanobacterial mixture containing toxic cyanobacterium Nodularia spumigena (70-110 microg nodularin l(-1), 24-h exposure followed by 144-h depuration period in clean water). Toxin concentration increased from initial 400 to 1100 mg kg(-1) after 24-h exposure, measured by liquid chromatography/mass spectrometry (LC/MS). Acetylcholinesterase activity (AChE), a biomarker of direct neurotoxic effects, showed inhibition after 12 and 24h exposure but returned to control level during the depuration period. Catalase (CAT) activity, an indicator of oxidative stress, showed significantly elevated levels in exposed mussels but only 72 h after the end of the exposure. No change in the activity of glutathione-S-transferase (GST) involved in conjugation reactions could be observed. A gradual yet incomplete elimination of nodularin (from 1100 to 600 mg kg(-1)) was observed during the depuration period, and the tissue levels were 30% lower in clean water after 24 h. The observed increase in oxidative stress indicated by elevated CAT activity is likely connected to detoxification reactions leading to the production of reactive oxygen species, including an apparent time lag in this specific enzymatic defence response. That no change in GST activity was observed suggests that this enzyme is not significantly involved in the detoxification process of nodularin-containing cyanobacterial extract in M. edulis.
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PMID:Accumulation and depuration of cyanobacterial toxin nodularin and biomarker responses in the mussel Mytilus edulis. 1736 31

Experiments were carried out on adult male zebrafish (Danio rerio) to assess early changes induced by waterborne exposure to different isotopic compositions of uranium (depleted uranium associated or not with 233U). Oxidative stress and neurotoxicity were selected as effect endpoints to characterize uranium chemo- and radiotoxicity. Catalase, glutathione peroxidase, and superoxide dismutase activities and total glutathione content of hepatic extracts, as well as brain acetylcholinesterase activity and uranium bioaccumulation, were measured. Oxidative stress induced by uranium exposure led to decreases in superoxide dismutase and catalase activity levels as well as total glutathione content in liver extracts. These perturbations were significantly more marked in 233U-exposed fish. Furthermore, significant increase in acetylcholinesterase activity was observed in brain extracts at the same level, whatever the isotopic composition of uranium.
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PMID:Bioaccumulation, oxidative stress, and neurotoxicity in Danio rerio exposed to different isotopic compositions of uranium. 1737 14

Ischemic stroke is a leading cause of mortality and disability particularly in the elderly. Hypertension is the most important risk factor in strokes, representing roughly 70% of all cases. Oxidative stress is believed to be one of the mechanisms taking part in neuronal damage in stroke. It is well documented that cholinergic system plays a key role in normal brain functions and in memory disturbances of several pathological processes, such as in cerebral blood flow regulation. This study investigated the oxidative status and acetylcholinesterase (AChE) activity in whole blood in patients diagnosed with acute and chronic stages of ischemia, as well as with hypertension. Malondialdehyde (MDA) levels and protein carbonylation content showed increased levels both in the acute ischemic groups and in the hypertensive group, when compared to the control. Catalase activity and reduced glutathione (GSH) levels in the acute group were also higher than in the hypertensive, chronic ischemic and control groups (p<0.05). The activity of AChE in acute ischemic patients was significantly higher than that presented by the control, hypertensive and chronic ischemic patients (p<0.05). The hypertensive group presented AChE activity significantly lower than control and chronic groups. In spite of having a defined location the ischemic event results in a systemic disorder that induces changes, which can be detected by measuring the peripheral markers of oxidative stress and AChE activity in erythrocytes.
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PMID:Oxidative stress and erythrocyte acetylcholinesterase (AChE) in hypertensive and ischemic patients of both acute and chronic stages. 1803 75

Arsenic is a known global groundwater contaminant. The organochlorine insecticide endosulfan has gained significance as an environmental pollutant due to its widespread use in the control of many food- and non-food-crop-damaging insects. The adverse effects produced by arsenic or endosulfan alone in humans and animals are well documented, but very little is known about the consequences of their coexposure. We evaluated whether their simultaneous exposure can induce oxidative stress and affect antioxidative systems and certain membrane-bound enzymes in erythrocytes of broiler chickens. Day-old chicks were exposed to 3.7 ppm of arsenic via drinking water or 30 ppm of endosulfan-mixed feed or similarly coexposed to these in the same dose levels for 60 days. At term, the impact of their coexposure was assessed by evaluating lipid peroxidation (LPO), activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), glutathione-S-transferase (GST), different ATPases and acetylcholinesterase (AChE) in erythrocytes, serum glucose, and levels of glutathione (GSH) and glycosylated hemoglobin (GHb) in blood. LPO was increased with all of the treatments. Catalase was decreased with endosulfan and the coexposure, but not with arsenic, whereas GSH was decreased with arsenic and endosulfan, but not with the coexposure. All of the treatments increased SOD and GPx activities. GST activity was increased only in the coexposed birds. None of the treatments affected the activities of total ATPase and Mg2+-ATPase. Na+-K+-ATPase activity was decreased in the endosulfan-treated and the coexposed birds. All three exposures increased erythrocyte AChE activity. Endosulfan increased the serum glucose level and arsenic and endosulfan increased GHb levels, but these were not altered in the coexposed birds. Erythrocyte protein content was insignificantly decreased with these treatments. Overall, the effects of coexposure were not appreciably different from either of the agents, except on AChE, GSH, and glucose. The results do not reflect any specific type of interaction between these agents in chicken erythrocytes, but they do indicate that the coexposure induces a low level of oxidative stress, which is comparable to that induced by arsenic or endosulfan.
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PMID:Effects of subchronic coexposure to arsenic and endosulfan on the erythrocytes of broiler chickens: a biochemical study. 1844 43

Laboratory studies were conducted to determine the effects of carbamate fungicide TATTU (mixture of propamocarb and mancozeb, 0.091 mg L(-1)) on biochemical markers of exposure in Rana ridibunda from clean (reference) and polluted sites. The untreated animals from the polluted site had lower Cu,Zn- and Mn-superoxide dismutase (SOD) and acetylcholinesterase activity, the levels of lipid peroxidation products (TBARS) and protein carbonyls in the liver and vitellogenin-like proteins (Vtg-LP) in the serum, but higher levels of glutathione in the liver in comparison with untreated frogs from the reference site. Catalase activity, superoxide anion and metallothionein levels were the same in both groups. The animals from two sites demonstrate different response on the effect of TATTU during 14 days. In the frogs from polluted site the oxidative damage (the decrease of Mn-SOD activity, lipids and protein oxidative destruction), neurotoxicity (depletion of acetylcholinesterase activity), and endocrine disruption (increase of Vtg-LP level) were revealed. On the other hand, the part of the indices in the animals from the reference site was unchanged after the treatment and the level of metallothionein was elevated demonstrating the satisfactory ability for the adaptation to unfavourable conditions.
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PMID:Different responses of biochemical markers in frogs (Rana ridibunda) from urban and rural wetlands to the effect of carbamate fungicide. 1858 79


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