03033nas a2200325 4500008004100000022001400041245012800055210006900183260001600252300001100268490000700279520209300286653001202379653001602391653001202407653001502419653003702434653001502471653002802486653001502514653001402529653001502543653001602558653001702574100001402591700001802605700001402623700001802637856005202655 2005 eng d a0166-445X00aToxicity testing of herbicide norflurazon on an aquatic bioindicator species--the planarian Polycelis felina (Daly.)0 aToxicity testing of herbicide norflurazon on an aquatic bioindic c2005 Jul 30 a342-520 v733 a

Norflurazon is a bleaching, preemergence herbicide. Due to its mobility and long half-life it presents a potential for groundwater contamination. The aim of our study was to investigate toxic effects of norflurazon on non-targeted aquatic bioindicator organism, the planarian Polycelis felina (Daly.). Animals were exposed to water solutions of norflurazon in concentrations 200, 20, 2 and 0.2 microM. Mortality, locomotive and morphological changes were monitored. Histological changes were studied both on treated and control animals with light microscopy. The primary DNA damage on single planarian cells was studied using the alkaline comet assay. Three comet parameters were studied: tail length, percentage of DNA in comet tail and tail moment. The results showed that norflurazon caused mortality, locomotive, morphological and histological changes in treated animals compared to corresponding controls. The most prominent histological changes were damage of the outer mucous layer, lack of rhabdites, damage to epidermis and extensive damage to parenchyma cells. The results of alkaline comet assay indicated that norflurazon in concentrations of 2 and 0.2 microM induces significant increase of primary DNA damage in planarian cells compared to the corresponding control animals. The mean values of all three measured parameters were significantly elevated on the fourth day of the treatment compared with the first and the seventh day. Based on the results of mortality and locomotive observations, we conclude that the fourth day of the treatment represents a certain threshold within planarian metabolism followed by the beginning of detoxification and recovery. However, histological preparations and comet data statistics show results indicating that high toxicity on the seventh day of the treatment gave the results of decrease of DNA damage due to the tissue/cell damage (apoptosis) and not recovery. The present study showed the ability of norflurazon to induce a wide range of different toxicological responses in freshwater planarian Polycelis felina (Daly.).

10aAnimals10aComet Assay10aCroatia10aDNA Damage10aDose-Response Relationship, Drug10aHerbicides10aHistological Techniques10aLocomotion10aMortality10aplanarians10aPyridazines10aTime Factors1 aHorvat, T1 aKalafatić, M1 aKopjar, N1 aKovacević, G uhttps://continenticola.myspecies.info/node/171702708nas a2200397 4500008004100000022001400041245014900055210006900204260001300273300001100286490000700297520155200304653001201856653002101868653002201889653001801911653002701929653001201956653003701968653003302005653001102038653001602049653001202065653001802077653001402095653002302109653001502132653001702147653001302164653001302177653001702190100001802207700001402225700001902239856005202258 2004 eng d a0887-233300aThe impairments of neoblast division in regenerating planarian Polycelis felina (Daly.) caused by in vitro treatment with cadmium sulfate0 aimpairments of neoblast division in regenerating planarian iPoly c2004 Feb a99-1070 v183 a

The effects of cadmium sulfate on the neoblast mitotic activity in regenerating planarian Polycelis felina (Daly.) were investigated. Mitotic abnormalities and chromosomal aberrations were evaluated after 6-h treatment and 24-h recovery period. The blastema were fixed, and examined cytologically through routine lactoorceine squash preparations. Mitotic indices were also determined. Cadmium sulfate induced a dose-dependent decrease in neoblast mitotic activity, accompanied with disturbances in distribution of cells over mitotic phases. Different cytological abnormalities with varying frequency were observed. Marked mitotic depression was concentration-dependent. Toxic effects of cadmium in regenerating planarian were mainly associated with mitotic spindle disturbances. Immediately after treatment mitotic abnormalities were prevalent over chromosomal and C-mitosis was the most prominent one. After 24-h recovery period a prevalence of mitotic over chromosomal aberrations was still present in animals treated with two higher concentrations of cadmium sulfate. However, the proportions of cells with chromosome stickiness in all treated animals were significantly increased compared to their post-treatment values. Observed mitotic impairments could be related to mitotic arrest contributing to retardations and delays, especially in animals treated with the highest concentration tested. The results obtained indicated usefulness of short term invertebrate assays as an alternative to in vitro pre-screening of toxic chemicals.

10aAnimals10aBiological Assay10aCadmium Compounds10aCell Division10aChromosome Aberrations10aCroatia10aDose-Response Relationship, Drug10aDrug Evaluation, Preclinical10aFemale10aForecasting10aMitosis10aMitotic Index10aMortality10aOxygen Consumption10aplanarians10aregeneration10aSulfates10aSurvival10aTime Factors1 aKalafatić, M1 aKopjar, N1 aBesendorfer, V uhttps://continenticola.myspecies.info/node/1715