Toksični učinak letalne koncentracije olovnog nitrata na škrge indijskog smeđeg soma Heteropneustes fossilis (Bloch)
| Autor: | Ram Sanehi Parashar, Tarun Kumar Banerjee |
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| Jazyk: | angličtina |
| Rok vydání: | 2002 |
| Předmět: | |
| Zdroj: | Veterinarski arhiv Volume 72 Issue 3 |
| ISSN: | 1331-8055 0372-5480 |
| Popis: | Toxicopathological impact of lethal concentration (925 mg/l) of lead nitrate on the gills of air-breathing catfish Heteropneustes fossilis was analysed. Following exposure the gills exhibited rapid alterations that include detachment and lifting of the epithelial linings from the surfaces of the gill filament (primary, PL) and respiratory (secondary, SL) lamellae. This led to extensive haemorrhage from the gills. Thus the quantity of blood flowing across the gills decreased substantially. Simultaneously, uncontrolled regeneration of the PL and SL occured, leading to extensive hyperplasia of the epithelial cells lining the PL, and SL. Consequently, the gill filaments appeared as a cylindrical solid mass of cells with very little or almost no free surface left on the SL for gaseous exchange. The goblet mucous cells also exhibited periodic fluctuations in their density and staining behaviour. The chloride cells showed periodic fluctuation in their number at different stages of exposure. The density of the chloride cells is inversely proportional to the thickness of the epithelial lining of the PL and SL. Due to prolonged exposure, the neighbouring SL fused together and the entire gills appeared as solid mass of undifferentiated cells. Subsequently, the ladder-like arrangement of the pillar cells-blood capillaries of the gills also collapsed, causing asphyxiation and the death of the fish. Analiziran je toksopatološki učinak letalne koncentracije (925 mg/l) olovnog nitrata na škrge indijskog smeđeg soma Heteropneustes fossilis (Bloch). Ubrzo nakon izloženosti olovnom nitratu na škrgama je utvrđeno odvajanje i podizanje epitelnog sloja od površine škržnog filamenta (primarno, PL) i respiratornih lamela (sekundarno, SL). To je dovelo do opsežnog krvarenja na škrgama pa se bitno smanjila količina krvi što protječe kroz njih. Istodobno je došlo do nekontrolirane regeneracija PL i SL što je dovelo do snažne hiperplazije epitelnih stanica koje okružuju PL i SL. Škržni filamenti su izgledali kao cilindrične nakupine stanica s vrlo malo ili gotovo bez slobodne površine preostale za izmjenu plinova na SL. Promjene su bile utvrđene i na vrčastim stanicama s obzirom na njihovu gustoću i svojstva bojenja. U različitim fazama izloženosti utvrđene su i povremene promjene u broju kloridnih stanice. Gustoća kloridnih stanica bila je obrnuto proporcionalna debljini epitelnog sloja PL i SL. Nakon produžene izloženosti spojile su se susjedne SL pa su škrge izgledale poput čvrste mase nediferenciranih stanica. Kao posljedica toga kolabirale su stupnjevito poredane stanice krvnih kapilara škrga što je dovelo do uginuća ribe. |
| Databáze: | OpenAIRE |
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