Effect of Cd(II) on Nucleolar Activity from Liver and Gill Cells of Odonthestes bonariensis (Pisces).

CARRIQUIRIBORDE P.; DE LUCA J.C.; RONCO A. E.

Porto, Portugal

Conferencia; Biomarker’s 2001; 2001

Centre of Marine and Environmental Research and Institute of Biomedical Sciences Abel Salazar, University of Porto

The nucleolus is a subcellular organelle related to the rRNA synthesis of the cell and therefore it is connected to the protein synthesis too. There is evidence that the nucleolar activity can be easily assessed by means of changes in morphological parameters such as area, volume and number. On the other hand, Cd(II) is a well known anthropic contaminant that affects the synthesis of some proteins like metallothioneins. The present study was focused on the sublethal effects of Cd(II) on the nucleolar activity in liver and gill cells from Odontesthes bonariensis after a short time exposure. Three month-old fish were exposed to 1 and 10 mg/L Cd(II). Fish were sampled at 1, 6, 12, 24 and 48h. Tissue samples were fixed in methanol-acetic acid (3:1). Slides were carried out using the routine air-dry technique and stained with AgNO3. Observations were done by means of optical microscopy and images captured by a digital camera. Image analyses was carried out using Image Pro Plus 3.0 software. The parameters assessed were nucleolar area, volume and number. Results showed a response of nucleolar activity in both gill and liver cells, with significant differences (p<0.05) at 24 and 48h exposure. The concentration producing nucleolar activity changes in treated organisms were at least one order of magnitude below the corresponding 48h LC50.  The present results indicate that nucleolar activity could be an early warning indicator of Cd exposure.