Ammonia triggers the promotion of oxidative stress in the aquatic macrophyte Myriophyllum mattogrossense

Nimptsch, Jorge; Pflugmacher, Stephan

Keywords: oxidative stress, eutrophication, ammonia, aquatic macrophytes, ros, Antioxidants 1. Introduction Aquatic ecosystems are increasingly subjected to anthropogenic pollution. The input of inorganic nitrogen due to human activities

Abstract

The effect of increased ammonia content on sub-acute biochemical responses was assessed in the rooted submersed aquatic macrophyte Myriophyllum mattogrossense (common name: ‘‘Brazil Milfoil’’ or ‘‘Matogrosso Milfoil’’), in a seven day aquarium experiment. The pH and temperature were monitored in order to determine the proportions of both ionized ðNHþ 4 Þ and un-ionized (NH3) forms of ammonia. Specific activities of several enzymes such as catalase (CAT), guaiacol peroxidase (POD), glutathione peroxidase (GPx) and glutathione S-transferase (GST’s) were measured as well as the content of the soluble antioxidant glutathione and lipid peroxidation were determined as these parameters are considered as indicators of cell-level disorder. The results showed that ammonia is able to generate oxidative stress, expressed through an elevated GSH content and the enhancement of CAT, POD, GPx and GST’s activities in treatments with elevated ammonia content. As the toxic mechanism of ammonia is a complex phenomenon, this work adds an additional point of view to explain in parts the oxidative stress generating effect of ammonia promoting oxidative stress. Additionally the different modes of action proposed by other research groups are discussed, thus trying to combine the various points of view.

Más información

Título de la Revista: CHEMOSPHERE
Volumen: 66
Editorial: PERGAMON-ELSEVIER SCIENCE LTD
Fecha de publicación: 2007
Página de inicio: 708
Página final: 714
Notas: ISI