The importance of lymphocyte micronucleus test for the detection of genotoxic events.

DNA lesion induced by xenobiotics is implemented either through direct interaction of the chemical with DNA through covalent binding or intercalation, or indirectly, through interference with the processes of DNA replication and repair, interaction with proteins, nuclease release from lysosomes etc. The present study emphasizes that the assessment of genotoxic risk arising from xenogenous substances demands the development of sensitive, direct and more exact genotoxic testing methods. One of them is micronucleus assay. It is a simple and quick test for investigating of cytogenic damage with the advantage that exposure to both clastogens and aneugens may be detected.

Effect of chloridazone on the animal organism.

The acute toxic effect of the herbicide chloridazone and mitochondrial respiration were investigated and typical clinical signs of intoxication were described in rats (Wistar), pheasants (Phasianus colchicus) and sheep (Slovak Merino). The LD50 of chloridazone was calculated to be for rats 800 mg/kg bw (range 552 to 1160 mg/kg bw) and for pheasants 3684 mg/kg bw (range 1768 to 7677 mg/kg bw). According to WHO chloridazone is moderately toxic for rats and slightly toxic for pheasants. The LD50 for sheep is 161 mg/kg bw (range 76 to 340 mg/kg bw). Chloridazone thus presents an acute risk for ruminants, which is in coincidence with the WHO classification characterising it as a very toxic compound. The following clinical features of intoxication were observed after p.o. administration of chloridazone: apathy, dyspnoea, hyperventilation, hypersalivation (sheep - foam hypersalivation), paralysis, tonic-clonic convulsions and death in clonic convulsions. Very quick rigor mortis. Chloridazone interfered with mitochondrial respiration in the liver of rats yet its mode of action was different from that of succinate substrate or glutamate-malate. Succinate dependent respiration was significantly decreased in both states (3 and 4) of respiration. Glutamate-malate respiration was not changed in state 4, though it significantly increased in state 3 after ADP administration. RCP (respiration control proportion) value was increased on using either of the substances.

Acute oral toxicity of the herbicide BUREX EKO in pheasants.

The aim of this study was to determine the acute LD50, clinical symptoms and pathological changes of acute BUREX EKO intoxication in pheasants according to OECD No 205. Medium lethal dose (LD50) of BUREX EKO in pheasant is 3.84 ml/kg body weight with the upper level of reliability 4.50 ml and lower level of reliability 3.27 ml/kg body weight. As far as the calculation to the effective substance is concerned it is 1077 mg of chloridazone per kg body weight with the interval of reliability from 919 to 1263 mg/kg body weight. Calculated the effective substance of chloridazone (3.84 ml is LD50 of BUREX EKO which contains 1077 mg of chloridazone) BUREX EKO can be classified as the moderately toxic substance to pheasants. There were following clinical symptoms of the BUREX EKO intoxication in pheasants: apathy, drowsiness, incapability to move, ruffled feathers, slight diarrhoea, strenuous respiration, tonico-clonical cramps before death, decease with the head expressively bent rearwards. There was a relatively fast beginning of rigor mortis in dead pheasants. Pathologico-anatomical dissection of the pheasants obtained under conditions of acute intoxication did not reveal any changes on the organs of both experimental and control pheasants which would be immediately connected with the effect of the administered substance. Hyperaemia was recorded by histologico-pathological investigation of the liver and kidneys. No changes on the brain and intestine wall were recorded.

Chronic influence of pyrethroid supermethrin on some reproductive features in Japanese quail (140 days long avian reproduction test).

We observed the influence of chronic effect of pyrethroid supermethrin on some reproduction features in Japanese quails. They received 3 different doses (P1 10.7 mg.kg-1.day-1; P2 21.4 mg.kg-1.day-1 and P3 35.7 mg.kg-1.day-1) of the tested substance during 20 weeks. The total health status, reproduction of Japanese quails, the damage rate (degree) of the organs and tissues as well as the determination of residue in the eggs and muscles of the experimental birds showed that pyrethroid insecticide supermethrin can be considered a safe pesticide.

[Biochemical aspects of the toxic effects of Supermethrin in a 140-day avian reproductive test]. / Biochemické aspekty toxického úcinku supermetrínu v podmienkach chronického 140-dnového aviárneho reprodukcného testu.

Chronic toxic effects of supermethrin on some biochemical parameters (AST, ALT, LDH, creatinine and total proteins) were investigated in 84 individuals of Japanese quail divided into four groups (control-K, experimental group I-P1, experimental group II-P2, experimental group III-P3) in the conditions of 140-day avian reproductive test. The three experimental groups received the tested substance at these doses: P1-10.7 mg/kg l.w./day, P2-21.4 mg/kg l.w./day, P3-35.7 mg/kg l.w./day. The results of observation of the enzyme activities AST and ALT show that only the AST activity (in the course of 140-day avian reproductive test) significantly increased to 1.225 mu kat/l in the females of experimental group P1, to 1.053 mu kat/l in P2 and to 1.014 mu kat/l in P3 against the control, in which the AST activity was 0.670 mu kat/l. The values of AST activity in the males were 1.143 mu kat/l in P1, 1.117 mu kat/l in P2 and 1.090 mu kat/l in P3 against the control 0.8395 mu kat/l. The investigation of variations in total LDH activity in Japanese quail after 140-day avian reproductive test has shown an increase in the LDH activity in the males (11.193 mu kat/l in P1, 11.269 mu kat/l in P2, 8.245 mu kat/l in P3 and 7.362 mu kat/l in K) as well as in the females (10.91 mu kat/l in P1, 12.023 mu kat/l in P2, 10.196 mu kat/l in P3 and 7.055 mu kat/l in K).(ABSTRACT TRUNCATED AT 250 WORDS)

Resistance of ruminal microorganisms to supermethrin.

The effect of the pyrethroid insecticide supermethrin on the growth and cyanogenic activity of 8 ruminal bacterial species (S bovis A0 24/85, S xylosus 310, E faecium 2, L plantarum, M elsdenii 4MJ, S ruminantium A17, B succinogenes 16J and B ruminicola 3/3) in pure culture was examined. Bacteria grown in 0.66 and 6.6 mg supermethrin/ml had similar growth rates and resistance to supermethrin. Production of cyanide from supermethrin occurred by all examined strains of ruminal bacteria, but the enzyme activity varied considerably with species and with the supermethrin concentrations.

Clinical signs and mechanism of supermethrin intoxication in sheep.

Three Slovak Merino sheep, weighing 38, 40 and 41 kg, were given single doses of 1500, 2700 or 3000 mg supermethrin/kg body weight. Clinical signs of intoxication were observed, and after death or sacrifice free cyanide levels were determined in the rumen contents and liver. The sheep that received 3000 mg supermethrin/kg had 7.2 and 0.58 mg cyanide/kg in the rumen contents and liver, respectively; the sheep that received 2700 mg supermethrin/kg had 5.8 and 0.52 mg cyanide/kg in the rumen contents and liver, respectively; whereas the sheep given 1500 mg supermethrin/kg had no free cyanide detected in the rumen contents or liver.