We observed differences in the quantity

and intensity of sting venom and skin mucus fractions obtained. While the fractionation of venom resulted in 11 fractions (Fv1 to Fv11), skin mucus resulted in 13 fractions (Fm1 to Fm13). With respect to peptide fractions, Pifithrin-�� molecular weight these occurred in greater number and intensity in the skin mucus whilst the protein fractions although equal in number were more intense in the venom. The results of MALDI-ToF mass spectrometry analyses of peptide content presented here offer additional support for the difference of these secretions. The molecular masses detected for fractions that seemed to be equivalent based on their retention times were found to be different. Also interesting to note that although the skin mucus peptide fractions were in greater intensity, the mass spectrometric analysis revealed a greater number of components for peptide fractions in the venom. We also note that of all analyzed fractions obtained in skin mucus only two were pure, showing molecular mass around 1500 Da, but these sequences were

not determined. Fish are in constant interaction with the aquatic environment, which contains a range of pathogenic or non-pathogenic microorganisms. The epidermis and the epidermal skin mucus act as biological barriers between fish find more and potential pathogens present in the environment (Shephard, 1993). Several previous Molecular motor workers have demonstrated the protective role of skin mucus and its components in several fish species (Austin and McIntosh, 1988; Fouz et al., 1990; Hjelmeland et al., 1983; Grinde et al., 1988; Nagashima et al., 2001; Sarmaşik, 2002), suggesting that the epidermal skin mucus acts as the first line of defense against pathogens and may be a potential source of new antimicrobial components. Although the skin mucus of some fish have been exploited for obtaining antimicrobials, there is little information so far about the peptides with antimicrobial activity in venomous fish such as that studied here.

Two peptide fractions (Fv1 and Fv2) obtained from sting venom showed antimicrobial activity against the gram-positive bacteria M. luteus, the gram-negative bacteria E. coli and against the fungus C. albicans. In contrast, the Fm1 and Fm2 skin mucus fractions presented antimicrobial activity only against E. coli. An interesting result obtained by Junqueira et al. (2007) was the induction of inflammatory activity by sting venom and skin mucus of C. spixii. Considering that the inflammatory process begins in the area of microcirculation we evaluated the action of sting venom and skin mucus fractions in microcirculation by employing intravital microscopy on the cremaster muscle of mice. This approach allowed direct visualization of the microcirculatory network in anesthetized and live animals.