Effect of chlorpyrifos and enrofloxacin on selected enzymes in rats.

This study examined the effect of chlorpyrifos and/or enrofloxacin on the activity of acetylcholinesterase (AChE) in the blood and brain, and the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum. The experiment was conducted on Wistar strain rats. Chlorpyrifos was administered with a stomach tube at a dose of 0.04 LD50 for 28 days and enrofloxacin at a dose of 5 mg/kg bw for 5 consecutive days. The experiment found that enrofloxacin changed the activity of the enzymes under study only to a small extent. At the dose applied in the experiment, chlorpyrifos decreased the activity of AChE significantly, both in blood and in the brain, and increased the activity of ALT and AST in rat serum. The administration of chlorpyrifos in combination with enrofloxacin changed the activity of the enzymes under study only slightly. A weaker, but longer, inhibition of AChE activity in both blood and the brain was observed in this group compared to the animals exposed only to chlorpyrifos. However, although enrofloxacin, like chlorpyrifos, increases the activity of ALT and AST in serum, their combined administration did not increase the hepatotoxic effect.

Concentration of hepatic vitamins A and E in rats exposed to chlorpyrifos and/or enrofloxacin.

The aim of the study was to determine the level of antioxidant vitamins A and E in the liver of rats exposed to chlorpyrifos and/or enrofloxacin. Chlorpyrifos (Group I) was administered at a dose of 0.04 LD50 (6 mg/kg b.w.) for 28 days, and enrofloxacin (Group II) at a dose of 5 mg/kg b.w. for 5 consecutive days. The animals of group III were given both of the mentioned above compounds at the same manner as groups I and II, but enrofloxacin was applied to rats for the last 5 days of chlorpyrifos exposure (i.e. on day 24, 25, 26, 27 and 28). Chlorpyrifos and enrofloxacin were administered to rats intragastrically via a gastric tube. The quantitative determination of vitamins was made by the HPLC method. The results of this study indicated a reduction in the hepatic concentrations of vitamins A and E, compared to the control, which sustained for the entire period of the experiment. The four-week administration of chlorpyrifos to rats resulted in a significant decrease of vitamins in the initial period of the experiment, i.e. up to 24 hours after exposure. For vitamin A the maximum drop was observed after 24 hours (19.24%) and for vitamin E after 6 hours (23.19%). Enrofloxacin caused a slight (3-9%) reduction in the level of the analysed vitamins. In the chlorpyrifos-enrofloxacin co-exposure group reduced vitamins A and E levels were also noted, but changes in this group were less pronounced in comparison to the animals intoxicated with chlorpyrifos only. The decrease in the antioxidant vitamin levels, particularly noticeable in the chlorpyrifos- and the chlorpyrifos combined with enrofloxacin-treated groups, may result not only from the increase in the concentration of free radicals, but also from the intensification of the secondary stages of lipid peroxidation.

Glutathione and glutathione-related enzymes in rats exposed to dimethoate and/or pyrantel.

The study was undertaken to examine the effect of single and combined administration of dimethoate (an OP insecticide) and pyrantel embonate (an anthelmintic agent) on the concentration of reduced glutathione (GSH) and the activity of glutathione peroxidase (GPx) and glutathione reductase (GR) in rats. Dimethoate (Group I) was administered to rats at a dose of 1/10 LD50 for 5 consecutive days and pyrantel embonate (Group II) at a dose of 1/5 LD50 for 3 consecutive days. The animals of group III were given both of the mentioned above compounds in the same manner as group I and II, but pyrantel embonate was applied on day 3, 4, and 5 from the beginning of dimethoate intoxication. Material from 6 rats randomly selected from each group was obtained after 3, 6 and 12 hours and 2, 7 and 14 days following the last applied dose of the compounds under study. It was found that application of pyrantel embonate caused only slight changes in the analysed parameters i.e. GSH, GPx and GR. Dimethoate administration caused disturbances in the antioxidative system manifested as a decrease in GSH concentration in the liver (max.--37.7% after 6 hours) and an increase of GPx and GR activities in erythrocytes (max.--21.7% and 29.6% after 3 hours, respectively), compared to the control group. The profile of changes after combined intoxication was similar, but their intensity was higher compared to the group of animals exposed to dimethoate only. Based on current studies, it was concluded that both dimethoate and pyrantel embonate at the applied doses showed a pro-oxidative activity.

Activity of selected antioxidative enzymes in rats exposed to dimethoate and pyrantel tartrate.

This study presents the results of research concerning the effect of single and combined application of pyrantel tartrate and dimethoate on selected antioxidative enzymes: catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx), in rat erythrocytes. Pyrantel tartrate was applied twice, at a dose of 85 mg/kg bw at a two week interval, i.e. on day 14 and 28 of the experiment, orally, in a water solution with a stomach tube. Dimethoate was administered with drinking water for 28 days at a dose of 25 mg/kg bw/day. It was found that pyrantel tartrate caused only small changes in the activity of the antioxidative enzymes under analysis. Subchronic exposure of rats to dimethoate caused a significant increase in the activity of CAT, SOD and GPx in erythrocytes, indicating the existence of strong oxidative stress. In combined intoxication, no significant effects of administering pyrantel tartrate on the activity of CAT, SOD and GPx was found in animals poisoned with dimethoate. The profile of changes was similar to that observed in rats exposed only to the organophosphorus insecticide. This may indicate a lack of interaction between the compounds used in the experiment.

Activity of superoxide dysmutase, catalase and glutathione peroxidase in rats exposed to chlorpyrifos and erofloxacin.

The aim of the study was to investigate the influence of administration of chlorpyrifos and/or enrofloxacin on the activity of chosen antioxidative enzymes i.e.: superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) in erythrocytes of rats. Chlorpyrifos was administered by stomach tube during 28 days at a dose of 3 mg/kg bw (0.02 LD50), and enrofloxacin was administered by stomach tube at a dose of 5 mg/kg bw during 3 subsequent days. It was stated that administration of enrofloxacin at applied dose did not cause any major changes in the activity of investigated antioxidative enzymes. The four-week exposure of rats to chlorpyrifos caused noticeable decrease in SOD and CAT activity in erythrocytes of rats at the beginning of the experiment (up to 24th hour) in comparison with the control group. The activity of GPx during all periods of the experiment was increased. In the group of animals in which both chlorpyrifos and enrofloxacin were applied, the profile of changes in activity of examined enzymes was similar to that one, which was observed after administration of chlorpyrifos exclusively, what may indicate lack of co-action between compounds used in the experiment.

The influence of administering "effective microorganisms" to pullets on chosen haematological and biochemical blood indexes.

"Effective Microorganisms" (EM)--a mixture of lactic acid bacteria, photosynthetic bacteria, yeasts and fungi are used mainly in agriculture and organic waste treatment. Recently, they have also been added to water and feed for animals, as well as to processing their excrements into compost and to eliminate the stench. The objective of the present study was to assess the influence of a 14-day administration of an EM solution in drinking water to layer hens on chosen haematological and biochemical indexes. The research was carried out on 120 hens divided into two equal groups. The birds in the experimental group were given drinking water with dissolved EM (5% solution), and those in the control group--water without the preparation. On the 64th day of the aviculture, the hens were weighted and their blood was taken from the wing vein for haematological and biochemical examinations. Administering EM with water to hens did not influence significantly their body weight nor chosen haematological and biochemical indexes. A significant increase was found only in the number of platelets, the level of albumins, the content of total cholesterol and the LDH activity, however, a decrease in the ALT activity was observed.

The effect of dimethoate and pyrantel on vitamin C concentration in the rat liver.

The aim of this study was to determine the content of vitamin C in the liver of rats exposed to dimethoate or pyrantel embonate as well as co-intoxication with both agents. Investigations were carried out in two stages. At each stage, the rats were divided into three experimental groups (I-III) and a control (C) group. In the first stage, rats from group I were administered pyrantel embonate at a two-week interval at a dose of 1/2 LD50, while the animals from group II received dimethoate for 28 days at a dose of 1/25 LD50, and those from group III - both mentioned compounds in an identical manner as in groups I and II. In the second stage, the rats from group I received pyrantel embonate at a dose of 1/5 LD50 for 3 consecutive days, while the animals from group II received dimethoate at a dose of 1/10 LD50 for 5 consecutive days, and those from III received both compounds, but pyrantel was administered on day 3, 4 and 5 of dimethoate administration. The concentration of vitamin C after pyrantel embonate and dimethoate administration was influenced not only by doses of the compounds used but also by the manner of their application (single or co-administration). Dimethoate delivered at a dose of 1/25 LD50 evoked an increase in vitamin C concentration that was observed to continue up to the 14th day after the exposure, whereas when applied at a dose of 1/10 LD50 it increased the vitamin C level only at the 3rd hour. A considerable decrease in the vitamin C level was reported after pyrantel treatment at a dose of 1/5 LD50. In rats from groups where the compounds were co-administered, increased level of vitamin C was observed at both stages of the experiment only in the first period after intoxication, i.e. up to the 6th hour.