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

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’-nucleotidade in adult zebrafish (Danio rerio) 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 in vitro 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.