Microcystin-LR acute exposure does not alter in vitro and in vivo ATP, ADP and AMP hydrolysis in adult zebrafish (Danio rerio) brain membranes

Maurício Reis Bogo,Carla Denise Bonan,Luiza Wilges Kist,Rachel Seemann Fritsch,João Sarkis Yunes

doi:10.4081/xeno.2012.e9

Abstract

Microcystins (MCs) are toxins produced by cyanobacteria during the blooms that could accumulate in aquatic animals and be relocated to higher trophic levels. Adenosine triphosphate (ATP) acts as an excitatory neurotransmitter and/or a neuromodulator in the extracellular space playing important roles in physiological and pathological conditions. The aim of this study was, therefore, to evaluate the acute effects of different concentrations of MC-LR on nucleoside triphosphate diphosphohydrolases and 5&rsquo;-nucleotidade in adult zebrafish (<em>Danio rerio</em>) brain membranes. The results have shown no significant changes in ATP, adenosine diphosphate (ADP) and adenosine monophosphate (AMP) hydrolysis in zebrafish brain membranes. MC-LR <em>in vitro</em> also did not alter ATP, ADP and AMP hydrolysis in the concentrations tested. These findings show that acute exposure to MC-LR did not modulate ectonucleotidase activity in the conditions tested. However, additional studies including chronic exposure should be performed in order to achieve a better understanding about MC-LR toxicity mechanisms in the central nervous system.

Highlights

Microcystins (MCs) are heptapeptides primarily known as potent hepatotoxins released into water during cyanobacterial blooms.[1]
The results have shown no significant changes in Adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) hydrolysis in zebrafish brain membranes
This study was designed in response to a series of factors: i) MCs synthesized by cyanobacteria can either accumulate in the brain and change locomotor behavior in fish; ii) the neurotoxic effects of MCs exposure are far from being completely understood; did not alter ATP, ADP and AMP hydrolysis stress, a dysfunction of cytoskeleton assembly, iii) zebrafish is a well-established organism in the concentrations tested

Summary

Introduction

Microcystins (MCs) are heptapeptides primarily known as potent hepatotoxins released into water during cyanobacterial blooms.[1]. MC-LR induced oxidative tion in zebrafish brain[4] and altered adult zebrafish swimming performance parameters.[12] This study was designed in response to a series of factors: i) MCs synthesized by cyanobacteria can either accumulate in the brain and change locomotor behavior in fish; ii) the neurotoxic effects of MCs exposure are far from being completely understood; did not alter ATP, ADP and AMP hydrolysis stress, a dysfunction of cytoskeleton assembly, iii) zebrafish is a well-established organism in the concentrations tested

Brief Report

Nucleotide hydrolysis assay

Discussion

In vitro exposure

Membrane preparation