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(41-24) Sublethal effects of the herbicide propanil on plasma eel metabolism. Fernandez-Vega, Cristina*,1, Sancho, Encarnacion1, Ferrando, Maria-Dolores1, Andreu, Enrique1, 1 Fac. Biological Sciences, Univ. Valencia; Dr. Moliner 50; Burjasot, Valencia, Spain ABSTRACT- Albufera Natural Park (Valencia, Spain) forms a relevant ecosystem where a traditional rice culture of inundation has being historically done. Herbicides used to control weeds in inundated rice fields can arrive to Albufera Lake and surrounding irrigation channel waters. Propanil (3,4-dichloropropionanilide), is one of the major herbicides world-wide employed on rice farming and is extensively used in this protected wetland. Populations of European eel, Anguilla anguilla, commonly inhabit this ecosystem. Fish exposure to sublethal levels of pesticides can produce a stressful condition and disorders of the normal animal physiology. The lethal toxicity (LC50) of propanil in the European eel (A. anguilla) was previously determinated resulting in 31.55 mg/L at 96 hours exposure. In order to investigate sublethal effects of propanil on fish physiology, a sublethal concentration (1/50 LC50-96h) was selected. Eels from Albufera Lake were exposed to 0.63 mg/L of propanil for 96 hours in a continuous flow-through system. At 0, 2, 12, 24, 48, 72 and 96 hours animals were randomly removed and anesthethized with MS222. Blood was taken out from the heart with a heparinized syringe and centrifuged. Finally, plasma was used for determination of glucose, lactate, total proteins and acetylcholinesterase (AChE, EC 3.1.1.7.) as total and specific activities of the enzyme. Propanil induced a significant high increase in plasma glucose levels (p<0.05) from the first hours of exposure compared with levels at 0 hours. It was accompanied with a rapid increase in blood lactate levels (p<0.05) and maintained throughout the toxicant exposure. On the other hand, the results showed that AChE activity and plasma total proteins were not significantly (p>0.05) altered by the exposure to this acetanilide herbicide. The effects observed in (A. anguilla) metabolism induced by propanil are discussed in terms of a generalized stress situation. Key words: plasma, metabolites, acetylcholinesterase, propanil-toxicity |
