, 2004) by Natterins, a new family of proteins with kininogenase activity found in this venom ( Magalhães et al., 2005). In previous studies, it was demonstrated that the injection of S. plumieri venom in the footpad or peritoneal cavity of mice leads to endothelial barrier dysfunction, microvascular hyper-permeability and sustained inflammatory response ( Boletini-Santos et al., 2008). Recently, we demonstrated that S. plumieri venom (0.4–5.0 μg/g mice) caused nociceptive and dose-dependent

edematogenic responses in mice footpad ( Gomes et al., 2011), similar to that described in humans by Haddad Jr. et al. (2003). Nevertheless, the molecular mechanisms of these local effects have not been elucidated. In the view of these facts, IWR-1 this study aimed to characterize the inflammatory reaction induced by S. plumieri venom, as well as to investigate the role of major inflammatory mediators involved in setting-up this response. Male Swiss mice, weighing about selleck inhibitor 20–25 g, were housed in the animal care facility

at the Federal University of Espírito Santo and used in accordance with the guidelines provided by the Brazilian College of Animal Experimentation (COBEA)/105-2011. Scorpionfish venom was obtained from wild specimens of S. plumieri, collected on shallow water beaches on the coast of Espírito Santo State – Brazil, and maintained alive in oxygenated seawater. The venom extraction was carried out according to the batch method ( Schaeffer et al., Y-27632 2HCl 1971) as adapted by Carrijo et al. (2005). Briefly, the dorsal (12) and anal (3) fin spines were removed from the fish (10–30 cm and 200–400 g), previously restrained by chilling at – 20 °C for about 30 min, stripped and their

contents solubilized in phosphate buffered saline (PBS) at 4 °C. The extract was centrifuged for 15 min at 4 °C/14.000 g to remove the insoluble particulate material and supernatant was collected and named S. plumieri Venom (SpV). The protein concentration was determined by the method of Lowry et al. (1951), using bovine serum albumin as standard. In order to determine the best storage conditions that maintain the inflammatory activity of the venom, samples of freshly extracted SpV were lyophilized or stored at 24, 4, −15 and −196 °C by 80 h. Then, edematogenic activity was induced in the intraplantar (i.pl.) region of the mice right hind paw (n = 4) using 15 μg of venom protein (fresh or stored) in 30 μL of PBS, according to Gomes et al. (2011). The paw thickness was assessed before venom injection for basal measurement and thereafter 0.5 h (n = 4), using a digital caliper (Zaas Precision). Results were expressed as mean ± SEM (Standard Error of the Mean) of the percentage of paw thickness increase ( Lima et al., 2003). Animals injected with 30 μL of PBS were considered as negative control. S. plumieri venom (15 μg of protein in 30 μL of PBS) or PBS were injected in the intraplantar region of right hind paw of mice. After 0.