Immune response of juvenile common carp (Cyprinus carpio L.) exposed to a mixture of sewage chemicals.

Pharmaceuticals and household chemicals are important components of municipal sewage. Many of them are biologically active, disrupting not only hormonal regulation of aquatic animals but also, indirectly, disturbing their immunological protection. In the environment, chemicals rarely act as individual substances, but as elements of mixtures. Therefore, the aim of this study was to check whether the acute laboratory exposure of common carp juveniles to a mixture of ibuprofen, sodium dodecyl sulphate (SDS), dimethyl sulfoxide (DMSO) and 17 α-ethynylestradiol in increasing concentrations, modifies the levels of innate immunity (lysozyme, C-reactive protein) as well as general stress (metallothioneins, heat shock proteins HSP70) markers in brain, liver, gills, spleen and mucus. The levels of the markers were measured by an immunodetection technique. Not only do the pharmaceuticals and household chemicals impair immunological reactions of young carp in various tissues but also do that in a concentration-dependent manner in the liver, gills, spleen and mucus. This has a very important implication, since it may result in higher sensitivity of young fish to pathogens due to energy allocation to defence processes. The comparisons of the pattern of stress reactions in the studied organ samples indicated that mucus appeared to be a good, non-invasive material for monitoring of environmental state and fish conditions.

DNA damage in grasshopper Chorthippus brunneus (Orthoptera) hatchlings following paraquat exposure.

Comet assay was applied to study genotoxic damage induced by paraquat (PQ) in brain cells of Chorthippus brunneus (Insecta: Orthoptera) hatchlings. Percentage of the comet fluorescence in the tail (TDNA), length of the comet tail (TL) and Olive tail moment (OTM) were used for quantitative assessment of the DNA damage. Multiple regression analysis supplemented standard statistical elaboration of the results. Increasing PQ concentrations applied either directly to the brain cells suspension (10, 50, and 250 µM PQ final concentration--in vitro protocol) or indirectly (50, 250, and 1250 µM PQ final concentration--in vivo protocol) provoked significant increase of oxidative damage to DNA (higher median TDNA and OTM values). The damage increased with time of exposure (0, 5, 15, and 30 min) following in vitro application, but decreased in longer interval (3 vs 24 h) after in vivo administration of paraquat. On contrary, median TL values did not correlate with paraquat concentration irrespectively of the exposure protocol. Possible reason of this discrepancy in light of paraquat toxicity is discussed.

Lipid peroxidation and activity of antioxidative enzymes in the rat model of ozone therapy.

Hypothetical, therapeutic effects of ozone were investigated in an animal model. One ml of oxygen or mixture of 40 micrograms ozone with oxygen were injected intraperitoneally to male rats for 10 days. Previously, rats had been poisoned with 50 ppm Cd2+ in drinking water for 12 weeks. Exhaustive treadmill running was applied to some animals before sacrification. Ozone injections increased iron-ascorbate-stimulated lipid peroxidation (LPO) in the liver and kidney, catalase (CAT) activity in the heart and glutathione S-transferase (GST) activity in the heart, kidney and liver. Oxygen increased GST activity in the brain and reduced glutathione peroxidase (GPX) activity in the kidney. Cadmium enhanced LPO in the liver and GST activity in the brain, heart, kidney and liver. In contrast to ozone, cadmium inhibited GPX activity in the brain, kidney and liver. Cadmium combined with ozone enhanced the changes of GPX activity in the kidney and liver, that of GST activity in the heart, kidney and liver as well as of CAT activity and LPO in kidney. The results suggest that ozone injections combined with tested factors may provoke an oxidative stress. The effects of ozone therapy can not be explained as the results of ozone action on the antioxidative enzymes in rat.

Iron ascorbate-stimulated lipid peroxidation in vitro. Why is the method controversial?

In vitro generation of thiobarbituric acid reactive substances (TBARS) is frequently used to assess organ susceptibility to lipid peroxidation. The yield of TBARS is severalfold enhanced by an addition of iron ions with reductors or chelators such as ascorbate, NADPH, ADP or pyrophosphate. The process cannot be interpreted in a simple way, since it involves several enzymatic and nonenzymatic reactions. There are no clear interpretations of the ambiguous effects of denaturating factors and chelating agents on TBARS generation. Also controversy arises from the curvilinear relationship between the homogenate concentration and the yield of TBARS. This has been modelled in the present work by combining two functions describing the sequential reaction with two limiting steps. One of them is related to catalytic action of iron and ascorbate, while the other to an enzyme, possibly phospholipase A2, as has been suggested by some investigators. Two models should be considered since it is impossible to decide which kinetic equation should predominate in the model. Nevertheless, the model reflects kinetic properties of the process. The effects of catalyst concentration and some other modification upon the yield of TBARS were also investigated experimentally. The results of experiments and modelling showed that the analytical procedures used by investigators need standardisation as the results obtained under a variety of procedures may reflect quite different properties of the living systems.

The activity of mitochondrial enzymes in the muscles of rats subjected to physical training and subchronical intoxication with lead and zinc.

The aim of this study was to evaluate the effect of lead and excess zinc on the adaptation of mitochondria from skeletal muscles to physical effort. Rats were intoxicated once a week for 12 weeks by subcutaneous injection of the solution containing 2 mg Zn+2 and/or 3 mg Pb2+ per kg of body weight. During the last 6 weeks, 6 times weekly, rats performed endurance training which involved swimming 15 minutes daily with additional load of 5% of the body weight. The activities of isocitrate (ICD), malate (SDH), succinate (MDH) dehydrogenases, cytochrome oxidase (COX) and protein content (PM) were determined in the mitochondrial fractions obtained from the soleus muscle (ST fibres), and from the superficial (FTb fibres) and deep (FTa fibres) parts of the gastrocnemius muscle. In the control group (C), which was injected with saline, higher activities of ICD and MDH were obtained in FTa and FTb fibres than in the ST fibres. SDH and COX had higher activities in FTa and ST compared to FTb fibres. Zinc treatment (Zn) caused diminution of ICD, SDH and COX activities in ST fibres. Lead intoxication (Pb) resulted in a decrease of MDH activity in all fibre types, and in a decrease of SDH activity in ST fibres. Simultaneous action of zinc and lead produced an increase in ICD activity and diminution of COX activity in FTb fibres. It also resulted in an increase of SDH and decrease of COX activity in ST fibres. These results suggest that the ST fibres are more susceptible to disturbances of adaptation to physical exercise caused by zinc and lead. There are no signs of uniform antagonism between zinc and lead action in the processes under investigation.

Sodium-dependent depolarizing potentials in veratrinized crayfish muscle fibres.

In the slow abdominal flexor muscle fibers of the crayfish Procambarus clarkii, veratrine or veratridine applied during several minutes produced the persistent transformation of the muscle fibre from a nonspiking into a Ca-dependent spiking one and spikes were followed by a long-duration depolarization. The long-duration potential depends on external Na+ but is not blocked by 30 microM tetrodotoxin (TTX). In solutions containing normal concentrations of Na+ (207 mM) the absence of Ca2+ or the presence of calcium channel blockers abolished both potentials. The results show that alkaloid toxins reveal a Ca2+-dependent, TTX-resistant Na+ conductance in crayfish tonic muscle fibres.

Metabolic adaptation of muscles to exercise, vibration and raised temperature under the influence of cernitins.

Wistar rats were used to study the effects of cernitins, i.e. aqueous and oil extracts of pollens, on the metabolic adaptation of the soleus muscle to exercise, vibration and raised ambient temperature. The animals were exposed to selected combinations of these factors for 5 days during 1.5 hour daily. A part of the animals was given orally cernitins in daily doses of 6 mg/kg of body weight for 10 days before the exposure. Among the adaptation changes studied in the soleus muscle, 24 hours after the last exposure, cernitins caused: a reduction of the amount of total protein, an increase in the proportion of soluble proteins in the protein fraction, an increase in the tissue oxygen consumption, an increase of already elevated pyruvate kinase activity, a further rise in ATP level, an increase in lactic dehydrogenase activity, a rise in the activity of cholinesterases. Moreover, it increased significantly the body weight and the weight of the studied soleus muscle. Cernitins, in combination with certain types of exposure used in this experiment, exerted a catabolic action, increased the rate of anaerobic metabolism and enhanced adaptation to exercise, vibration and temperature. The direction of the adaptation changes depended on the type of exposure to environmental factors.