Unusual profile of leukocyte recruitment in mice induced by a skin secretion of the tree frog Phyllomedusa hypochondrialis

Phyllomedusa hypochondrialis skin secretion can cause both systemic and local effects. In this study, we describe the pattern of local acute inflammatory response after P. hypochondrialis skin secretion injection. The inflammatory reaction in the mice footpad was analysed, including the leukocyte recruitment into local tissue from the peripheral blood, in a mouse model of tissue injury. We also investigated the release of the cytokines IL-1, IL-6 and TNF-α, chemokines KC and MCP-1 and the eicosanoids LTB 4 and PGE2 in mice. The present findings support the ability of P. hypochondrialis skin secretion to induce local inflammation. In addition, these skin secretion components play a role in the initial rolling and slowing of recruited leukocytes and the transition from rolling to adhesion. Levels of the proinflammatory cytokine IL-6, chemokines KC and MCP-1 as well as the eicosanoid PGE2 were significantly increased after injection of a skin secretion of P. hypochondrialis (0.6 μg/30 μl intraplantar), whereas no changes in other parameters were observed. Finally, the mechanisms involved in the local inflammatory process induced by P. hypochondrialis skin secretion is one of the questions of relevance related to the complex pathophysiology induced by this particular secretion and other toxins.