Carla Simone Seibert

Studies on pharmacological properties of mucus and sting venom of Potamotrygon cf. henlei

Stingrays from the Potamotrygon cf. henlei species are widely distributed in high numbers throughout the rivers of central-west Brazil, being the source of numerous envenomations occurring in the dry season, posing a serious public health problem even if not properly reported. The accidents usually involve fishermen and bathers, and to date there is no effective treatment for the injured. Considering these facts and limitations of studies aiming at understanding the effects induced by P. cf. henlei envenoming, this study aimed to describe the principal pharmacological and certain biochemical properties of the mucus and sting venom. We found that mucus and sting venom is toxic to mice having nociceptive, edematogenic and proteolysis activities. Our results also indicate that the inflammatory cellular influx observed could be triggered by the venom and mucus. Furthermore the venom and mucus were partially purified by solid-phase extraction tested for antimicrobial activity in which only the mucus presented activity. It could be inferred from the present study that P. cf. henlei venom possesses a diverse mixture of peptides, enzymes and pharmacologically active components.

Parâmetros eritrocitários e curva de fragilidade osmótica de Colossoma macropomum (Pisces, Osteichthyes, Mileinae) em cativeiro

In order to establish reference values for certain haematological parameters and osmotic fragility curve for the blood of Colossoma macropomum , blood samples were collected from 38 fish bred on farms in the state of Tocantins, Brazil. Red blood cell count, haemoglobin content and haematocrit were determined. Osmotic fragility curves were determined for 30 minutes under resting conditions at 30oC, incubated curves at 37, 30 and 27oC for 24 hours and incubated curves for 12 hours at 27oC. The haematimetric values obtained were: red blood cell count= 1.58 ± 0.08 x10 12 /L; haemoglobin= 7.2 ± 0.32 g/dL; haematocrit= 34.0 ± 1.6%; MCV= 217.6 ± 13.2fL; MCH= 46.3 ± 2.6 pg and MCHC= 21.5 ± 1.4%. Osmotic fragility of fish erythrocytes was assessed according to haemolysis rate. Haemolysis began at 85.5 mM NaCl and total haemolysis occurred at 17 mM NaCl. Samples from incubated curve for 24 hours showed total haemolysis in all concentrations, regardless of temperature. In the samples from incubated curve at 27oC for 12 hours initial haemolysis was observed at 154 mM and total haemolysis at 17 mM NaCl