Before analysis, some changes were defined ( Table 1) in order to facilitate their identification during experiment. Evaluation of S. cyanea venom-induced oedema was performed by a single subplantar injection of four different venom doses, 5, 12.5, 25 AZD2281 price and 50 μg/paw, in 5 μL saline (n = 5 in
each group), into the right hindpaws of sodium thiopental-anesthetized Wistar rats (200–250 g), similar to the protocol previously described by Eno (1997). Saline solution (0.9%) in the same volume was injected into the left paws as controls. The volume of each paw was measured with a manual hydroplethysmometer immediately before subplantar injection and at 10 min intervals during a one-hour experiment. Paw volume was always assessed by the same investigator. Data obtained from each rat in each time point were adjusted according to the following formula: (value obtained − baseline value of the rat)/(maximum value observed − baseline value of the rat) and were expressed as percentages
of changes in paw volumes. A male guinea pig (Cavia porcellus) was deprived of food for 24 h and euthanized with 120 mg/kg Thiopental intraperitoneal. Segments of 1.5–2.5 cm of the distal end of the ileum were used. After the intraluminal check details contents were flushed, the ileum segments were suspended in a 10 mL bath containing aerated Tyrode solution (in mM: NaCl 137, KCl 3, CaCl2 2, MgCl2·6H2O 1, NaHCO3 12, glucose 6, NaH2PO4 0.4, pH 7.0) kept at 32 °C. The ileum segments were equilibrated for 15 min
prior to the tests. Isometric muscular responses were recorded on a Narco polygraph with Narco force transducers (model F-60). Responses induced by either whole venom or drugs were obtained in a non-cumulative manner from ileum segments. Different concentrations of Bradykinin (BK; 0.01–1.06 μg/mL) and S. cyanea whole venom (20–200 μg/mL) were used in this assay. A single concentration (0.22 μg/mL) of Captopril (Cap) was used in the tests. Bradykinin and Captopril were purchased from Sigma Chemical Co. Captopril was administered alone or combined with bradykinin or whole venom, and was added to the bath three minutes before bradykinin or whole venom administration. Two different S. cyanea venom doses – 50 click here and 200 μg – were used to determine the hemorrhagic activity on Swiss albino mice (M. musculus) of approximately 30 g. The venom was dissolved in 100 μL saline solution (0.9%) and injected by intracutaneous route on the dorsal region of the mice; the venom was injected on the left side of the skin and saline solution, as negative control, on the right side. After two hours, the mice were euthanized, followed by the skin removal and measurement of the hemorrhagic halo in its internal surface. The diameter of the hemorrhagic haloes was measured with a digital pachymeter.