PARENT SESSION
73 - Effects of Pharmaceuticals
8:00 AM to 6:30 PM, Wednesday, 15 May 2002
Exhibition Area

(73-10) In vitro toxicity of five veterinary pharmaceuticals on RTG-2 and RTH-W1 fish cell lines.

Babín, Mar¹, Boleas, Sara^*,1, García, Pilar¹, Carbonell, Gregoria¹, Tarazona, José¹, ¹ INIA. Department of Environment. Crta. de La Coruña Km 7., Madrid, Spain

ABSTRACT- The large number of products used in veterinary medicine are derived from very different groups of active ingredients. An environmental risk assessment is required for new substances. The toxicity of five veterinary products: the antibiotics tetracycline (TC) and oxytetracycline (OTC), germicides sulfachlorpyridazine (SCP) and septrin (ST), and antiparasitic chlorpirifos (CHP) was tested after 24h of toxic exposure on RTG-2 and RTH-W1 fish cell lines, through changes of ethoxyresorufin O-deethylase (EROD) and beta-galactosidase (-Gal) enzymatic activities, neutral red assay (NR) and FRAME KB protein assay (KBP) as toxicity endpoints. SCP had no effects at the highest tested concentration, 200 mg/L. The -Gal activity was undetectable in CHP treated cells. A decrease in EROD activities of RTG-2 and RTH-W1 cells exposed to TC, OTC and CHP was observed, while the activity was induced by ST. The EROD EC50s ranged between 1.89 x 10-2 mg/L (CHP) to 71.64 mg/L (TC) on RTG-2 cell line, and between 2.61 x 10-2 mg/L (CHP) to 167.63 mg/L (TC) on RTH-W1 cell line. The -Gal EC50s ranged between 29.26 mg/L (ST) to 91.67 mg/L (TC) on RTG-2 cell line, and between 17.68 mg/L (ST) to 84.59 mg/L (TC) on RTH-W1 cell line. The neutral red and protein EC50s were in general less sensitive than enzymatic EC50s. All assays were carried out in each well. Concentrations of the products of the EROD (resorufine) and -Gal (4-methylumbelliferone) reaction and neutral red and total proteins were measured in the same well with a fluorescence-absorbance plate reader. Funded by EU project ERAVMIS CC1999-0003-EVKI

Key words: veterinary products, RTG-2, RTH-W1