Stingray (Potamotrygon rex) maturity is associated with inflammatory capacity of the venom.

Several studies have been carried out with venom from sting and mucus of stingrays of marine or fluvial environments to compare the toxicity of their venom. However, studies demonstrating the existence of the influence of both sex and the maturation stage of stingrays on the variability of the toxic effects of venom are still scarce. Here, we investigated whether the sex and/or the stage maturation of the Potamotrygon rex stingray influence the toxic capacity of the venom to develop acute inflammation in mice. We carried out the main toxic activities in mice using venom from female or male of young and adult stingrays. Our results described here show that the nociception is mainly induced by venom from young female stingrays. In contrast, we observed the action of venom from both sex of adult stingrays in the induction of exudative phase of inflammatory process, including vascular leakage and neutrophil infiltration. Our data illustrate that the composition of the venom of P. rex is influenced by the stage of maturity of the stingray, modulating the production of peptides and proteins capable of acting on leukocytes-endothelial interactions and favoring neutrophil infiltration to the damage tissue.