(1971). The whole venom apparatus or 15 spines from a medium size fish (about

20 cm in length and ∼400 g weight) yielded an average of 10–16 mg of protein. The fresh venom extract (SpV) was immediately used for cardiovascular, edema-inducing and nociceptive assays. The protein concentration of the S. plumieri venom was determined by the method of Lowry et al. BGB324 price (1951), using bovine serum albumin as standard. All procedures were conducted in accordance with the Biomedical Research Guidelines for the Care and Use of Laboratory Animals (1996), as stated by the Brazilian College of Animal Experimentation (COBEA). The ability of S. plumieri venom to induce edema was studied in male Swiss mice (20–25 g) according to Lima et al. (2003). Samples of 30 μl of sterile phosphate buffer saline (PBS) containing different doses of SpV (7.5, 15, 60 μg of protein/animal) check details were injected via intraplantar (i.pl.) route in the right hind paw of mice. Local edema was quantified periodically in 0.5, 2, 4, 6, 12, 24, 48, 72 and 96 h after injection (N = 4) by measuring the thickness of injected paws with a digital caliper (Zaas Precision). Mice injected with sterile PBS were considered as control group. Results were expressed as percentage increase

of paw thickness after venom administration. Nociceptive activity of the SpV was assayed according to Hunskaar et al. (1985). Each mouse (20–25 g) was kept in a chamber mounted on a mirror. After an adaptation period (10 min), 30 μl of sterile PBS containing different doses of S. plumieri venom (7.5, 15, 30, 60 and 100 μg of protein/animal) were injected (i.pl.) in the right hind paw of mice (N = 4). Afterwards, each animal was returned to the observation chamber and the period of time spent licking or biting the right hind paw was recorded during 30 min and taken as index of nociception. Mice injected with sterile PBS were considered as control group (N = 4). Effects of SpV on blood pressure and heart rate were evaluated in male Wistar rats (250–300 g, N = 7) anesthetized 4-Aminobutyrate aminotransferase with urethane (1.2 g/kg,

i.p.). A midline incision was made in the cervical region and polyethylene catheters (PE-50) were implanted into the carotid artery and jugular vein of rats for cardiovascular recordings and venom injections, respectively. During all procedures, depth of anesthesia was checked through the pinch of the rear paw. When necessary, additional doses of anesthetic were injected. During all experiments, animals breathed spontaneously. The venom extract was administrated in bolus in a dose of 300 μg protein/kg in 100 μL of saline. The dose used was selected according to our previous work ( Gomes et al., 2010). The pulsatile arterial pressure (PAP) was recorded through a blood pressure transducer (Grass Instrument Div., Warnick, USA) and signals were processed using the BIOPAC-System (MP100, Model PT300, Santa Barbara, USA).