Bioconcentration pattern in biofluids of fish exposed to carbamazepine, sildenafil and their mixtures.

ELORRIAGA, Y.; RONCO, A.E.; CARRIQUIRIBORDE, P.

Vancouver

Congreso; Society of Environmental Toxicology and Chemistry North America 35th Annual Meeting; 2014

SETAC-NA

Sewages are the main source of environmental pharmaceuticals and concern exist on the potential impact of these emerging pollutants on the aquatic ecosystems. Complex mixtures of several pharmaceuticals are commonly found in sewages. In particular, carbamazepine was found as the most ubiquitous drug in sewages, but it is not alone; it is always accompanied by many other pharmaceuticals such as sildenafil. Understanding the accumulation of pharmaceuticals in aquatic organisms is important to develop models for predicting exposure and assessing potential environmental risks. In particular, the bioaccumulation of pharmaceuticals mixtures was little explored. In the present study the accumulation pattern of these two pharmaceuticals in the plasma and bile of the common carp (Cyprinus carpio) was assessed under single and combined exposures. Fish juveniles were waterborne exposed to single and combined environmentally (0,042 µM) and pharmacologically (0,042 mM) relevant equimolar concentrations y of carbamazepine and sildenafil during 96h. Bile and plasma were treated with the same volume of cold acetonitrile and centrifuged 10.000g for 15 min. Supernants were analyzed by HPLC-MS using electrospray ionization in positive mode and analyzed in full scan. Extracted ion areas for each compound in the bile and plasma of fish under each treatment and in the respective water samples were compared. In fish exposed to the pharmacological levels, concentrations of carbamazepine and sildenafil in the plasma of single exposed fish were around 10 and 20 times lower than in the water, respectively. On the other hand, in fish exposed to the mixture concentrations in the plasma were similar of that in the water for both compounds. In the bile concentrations were always in the same order of magnitude than in the water for both compounds. In addition, relative concentrations of carbamazepine and sildenafil were 1.5 in the plasma and 0.7 in the bile independently of the single or combine exposure. At the environmental relevant exposure level sildenafil was detectable but not quantifiable, so samples will further run using single ion mode to enhance sensitivity. Results not only shed light on the accumulation of the studied pharmaceuticals but also indicate different bioconcentration patterns between single and combined exposures.