Barietin, a snake venom vascular endothelial growth factor from puff adder Bitis arietans venom, increases the heart rate with minor effect on blood pressure in rats

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  Barietin, a snake venom vascular endothelial growth factor from puff adder Bitis arietans venom, increases the heart rate with minor effect on blood pressure in rats ABSTRACT Snake venom vascular endothelial growth factors (svVEGFs) are homodimeric proteins comprising two equal subunits bound by two intermolecular disulfide bonds. The main biological effects of svVEGFs are local vasodilatation, increasing of vascular permeability, and hypotension. Barietin, a svVEGF purified from the venom of puff adder Bitis arietans , differs from other representatives of this toxin family by its shortened C-terminal amino acid sequence. No data about barietin effects on hemodynamics are available. Studying those in rats we found that barietin at a dose of 1 mg/kg significantly increased heart rate, exerting only a minor influence on blood pressure. In this respect, it differs from other svVEGFs having a significant effect on blood pressure. We aimed to find the barietin active fragment which m...

A histopathological guide for the social spider Stegodyphus dumicola

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A histopathological guide for the social spider Stegodyphus dumicola

Abstract

The study of invertebrate pathology relies on histopathological tools to define visible internal structures and processes in understudied taxa like spiders. Histopathology involves the infiltration of tissues and organ structures with wax or resin, allowing for the visualisation of cellular anatomy and morphological structure, which can lead to the identification of abnormalities (e.g., pathology) and symbioses (e.g., parasites). In this study, southern African social spiders − Stegodyphus dumicola (Araneae: Eresidae) − were histologically prepared whole and their tissue appearances described (eyes, stomach, heart, ovaries, cuticle, stercoral pocket, chelicerae, book lungs, and silk gland). In addition to healthy tissues, an intranuclear, baculovirus-like pathology was identified. The availability of this material and whole-preparation method makes for a valuable histological resource, where few such resources currently exist for spiders.
Clark, G., Keiser, C. N., Cassidy, S. T., Dalton, D., & Bojko, J. (2024). A histopathological guide for the social spider Stegodyphus dumicola. Journal of Invertebrate Pathology, 108236. https://doi.org/10.1016/j.jip.2024.108236