Cellular migration induced by Thalassophryne nattereri fish venom and its toxins (Natterinsand Nattectin)

Mello-Reingruber P; Pavão DL; Lima C; Lopes-Ferreira M.

Laboratório de Imunopatologia, Instituto Butantan, São Paulo, Brazil

Thalassophrynenattereri is one the most venomous brazilian fish, found in north and northeast regions. It has one of the most developed inoculation system, composed by 4 spines, and 4 associated glands. Envenomation caused by this fish represents an important medical, economical and social problem. Until now, there is no efficient treatment for the local pain, oedema and necrosis induced by this venom. Recent studies have demonstrated the complexity of the venom leading us to further investigations with their toxins. The aim of this work was to evaluate the inflammatory response induced by the venom and its main toxins, Natterins and Nattectin. To isolate the toxins, the venom was submitted to ion-exchange chromatography. Then, Balb/c mice were injected intraperitoneally with 10 mg of venom or toxins in 500 mL of sterile PBS. At different time points after injection (6, 24, 48, and 72h) the animals were bled, and the peritoneal cavity of the mice were washed for collection of cellular suspension for cell counts. Total cell counts were performed in a hemocytometer and differential cell counts in cytocentrifuge preparations stained with Wright-Giemsa. Ours results show that venom induced a later influx of cells to peritoneal cavity significantly different from control-group (PBS). Neutrophils and macrophages were first observed at 24 h after injection, and in 48h after injection the influx was characterized by the presence of macrophages, and in 72h observed the influx of lymphocytes. In contrast, Natterins elicited an earlier increase in neutrophils, macrophages, and lymphocytes at 6h after injection. Twenty-four and 48 h after injection the influx was represented by increase in macrophage number, after which it decreased toward background levels. The total number of cells in peritoneal cavity recovered from mice injected with Nattectin was significantly different from control-mice throughout the period of time analysed. We observed at 6h an increase in neutrophil number, followed by an increase in macrophages and lymphocytes at 24h, and only in macrophage number in 48 and 72h. Changes in peripheral blood were observed in mice injected with venom or toxins throughout the period of time analysed. There was a significant increase in lymphocyte number in peripheral blood mainly induced by Natterins and Nattectins. These results suggest that T. nattereri venom, Natterins and Nattectin were able to induce an intense cellular recruitment to the peritoneal cavity, however this presented different patterns, in number, as in cellular types of cells.

Supported by FAPESP

Correspondence to: patriciareingruber@hotmail.com