CHARACTERIZATION OF THE EFFECTS OF CATFISH Pseudoplatystoma fasciatum VENOM IN THE MICROCIRCULATION AND MUSCLE FIBERS: AN INTRAVITAL MICROSCOPIC STUDY

ERLICHMAN C. (1), CONCEIÇÃO K. (2), PIMENTA D.C. (2), CHARVET-ALMEIDA P. (3), LOPES-FERREIRA M. (1)

(1) Lab. Imunopatologia, (2) Lab. Especial de Toxinologia Aplicada (CAT/CEPID), Instituto Butantan, São Paulo, (3) Universidade Federal do Paraíba.

One of the most abundant venomous species of catfish found in the North of Brazil is Pseudoplatystoma fasciatum (surubim). The accidents are characterized by local effects as intense pain and edema. The aim of this study was characterize the effects of the venom on the microcirculatory net and on muscle fibers, using intravital microscopy. In addition, eletrophoretical and cromatography profile of the venom was determined. The cremaster muscle of Swiss mice were displayed and different doses of the venom (5, 15, 30, and 60 µg) were topically applyed. Control experiments were performed by applying 30 ml PBS under otherwise identical conditions. Five minutes of observation were recorded before application of the venom to analyze the dynamics in control tissue. Experiments were carried out for up to 30 min. The higher dose of venom (60 µg) induced hypercontraction in muscle fibers, a signicant increase of leukocytes rolling, and a blood clot formation in venules. After application of 30 µg the same alterations were obseverd but in later periods. Using 15 µg it was obseved only hypercontraction in fibers. No alteration were seen after 5 µg application. The electrophoretic profile (SDS-PAGE) showed intense bands at 18, 25, and 66 kDa. Subsequently it was carried out chromatographic profile usig HPLC that showed 3 hidrofilic peaks and 2 hidrofobic peaks. These data suggest that the P. fasciatum venom induce an important inflammatory activity characterized for alterations in the microcirculation and muscle fibers, and these modification could be related with toxins present in the venom.

KEY WORDS: Catfish, venom, Pseudoplatystoma fasciatum, intravital microscopy.

FINANCIAL SUPPORT: Fapesp and CNPq/PIBIC.

CORRESPONDENCE TO: Clarisse Erlichman- clarisseerlichman@terra.com.br