Effect of Bothrops diporus venom on the vascular system of Gallus gallus domesticus embryos

Abstract

The majority of snakebites in northeastern Argentina are caused by Bothrops diporus (yarará chica). Envenomation causes predominantly local myotoxicity, characterized by myonecrosis often associated with hemorrhage, blistering and edema. The venom proteome of this snake comprises PI- and PIII-SVMPs, PLA2 molecules, BPP-like peptides, L-amino acid oxidase and serine proteinases. The aim of this work was to evaluate the changes induced by B. diporus venom in the vascular system of chicken. Briefly, fertilized chicken eggs of Gallus gallus domesticus were obtained from ?La Elina? establishment, disinfected and then incubated at 37°C and 65% relative humidity. The viability of the embryos and the vasculature of the CAM were visually inspected. An opening on the apex of the eggs was made on day 8, venom solution (1 mg/mL) was injected and then sealed with parafilm to avoid contamination and desiccation. Controls were injected with sterile physiological solution. After 48h incubation, parafilm paper was removed, the orifices were enlarged and embryos were removed. The embryotoxicity of the venom was analysed by histological evaluation. Histopathological evaluation evidenced, specifically in the cardiac tissue of the atrial region, disorganization and spaces of loss of muscle fibers. The capillaries showed abundant prolongations and the light partially occluded, the thickness of the endothelial wall was variable. In the ventricular region, areas of muscle fiber necrosis and infiltrate were observed. At the level of the chorioallantoic membranes an increase in capillary thickness was observed, accompanied by cytoplasmic acidophilicity. Endothelial vascular damage caused intense edema, which can be associated with hypoxic phenomena and ischemic processes that would generate cell death. In conclusion, Bothrops diporus venom induces alterations in the vascular system of the G. g. domesticus embryo that contribute to tissue ischemia and necrosis intoxication.