CONICET | Buscador de Institutos y Recursos Humanos

The occurrence of xenobiotics in the diet of animals is a factor that can affect important functions in them. In response to these xenobiotics, organisms must rapidly perform various behavioral and physiological adjustments in order to survive. Digestive tract is the most important organ involved in coordinating the digestion and acquisition of nutrients, both vital function for organisms. This system has a high capacity to adapt to different conditions, both internal signals and external agents. In this sense it has been observed that certain environmental pollutants can affect the enzymatic activity of the digestive system in some vertebrates. However, this effect is poorly studied in birds. Considering that atrazine is a widely used pesticide in our country and worldwide, and that negative effects on the physiology of some organisms have also been described, we propose as the general objective of this study to elucidate the long-term atrazine effects on digestive enzymes of Eared Dove (Zenaida auriculata). To achieve our goal, we established three independents groups of birds (n=6 each group),two groups were exposed during 15 days to 25 mg/kg and 250 mg/kg atrazine concentration in corn oil administered by intermittent gavage each day at the same time, and one control group that were administered only with corn oil without atrazine. After exposure, body weight measure, blood extraction and subsequent removal of the intestine, stomach, liver and pancreas were performed at the same time (8:00 am), to avoid disturbing by circadian/daily variation. The intestinal enzymatic activity of sucrose and maltase was determined in proximal, medial and distal portions. Statistical analysis performed for enzymes was RM-ANOVA and one-way ANOVA for organ mass (Tukeypost-hoc test, p < 0.05). No difference between groups was observed in enzyme activity of maltase and sacarase (p > 0.05), body mass, intestine, stomach and liver mass (all´s p > 0.05). The pattern found of intestinal enzymes activities were similar as those reported for other bird species, a higher activity on proximal and medial section. Although atrazine has been shown to have pathological effects in some species of birds, our results showed a non-significant inhibition of these enzymes in doves exposed to atrazine and a lack of effect in organ mass. However, further histological studies are necessary to support this observation in digestive organs. About enzyme activity, in vitroexperiments could give more information about enzyme activity inhibition, since the presence of crop in this birds could interfere the real concentration in the gut. Supported by CyT-UNSL PROICO 02-0820 and FONCYT PICT-201-0595.

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