engleski

Toxic effects of copper upon the planarian Polycelis felina (Daly.)

In this paper we established the effects of low doses of copper upon the planarian Polycelis felina (Daly.) in laboratory conditions. Six groups of ten animals were treated for 24 hours with 50, 100 and 150 umol/dm3 of copper (II) acetate. The seventh group of ten nimals was kept in clean water and was usedas a control group. Morphological changes and changes in behaviour were monitored for twenty days. For cytological and histological analysis of tissue of treated animals, markedly damaged planarians were fixed 24 hours after the beginning of treatment and also on second, third and seventh day after the treatment. Bouine fixative was used for fixation. The fixed tissue was embedded in paraplast and cut by microtome. The preparations were stained with Hämallaun-Eosine and embedded in Canada balsam. Immediately after treatment damaged parts of planarians were fixed with glutaraldehide and postfixed with osmium (VII) oxide, and cellular changes were examined under electron microscope. The tissue was dehydrated in ethanol and embedded in epoxy raisin. The cuts were contrasted with uranyl acetate and additionally fixed with Reynolds' solution. Water solution of copper (II) acetate causes distinct changes in behaviour of treated planarians, as well as mortality, morphological, cytological and histological changes immediately after the treatment. Depigmented areas and large hollow channels filed with mucus are result of damages to cellular membranes, nucleus, endoplasmic reticulum and mitochondria of many parenchymal cells. Even after regeneration, deformations were found in smaller number of damaged body parts as result of disturbed differentiation of neoplasts and morphogenesis. Copper concentration of 100 and 150 umol/dm3 caused highest mortality and most distinct changes in behaviour, morphological, cytological and histological structure of planarians. Most planarians were able to regenerate damages by means of neoblasts.

Copper; Toxicity; Polycelis felina; cytological damages

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