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...

Spiders (Arachnida: Araneae) of a wildlife and cattle savanna ranch in South-Western Zimbabwe

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Spiders (Arachnida: Araneae) of a wildlife and cattle savanna ranch in South-Western Zimbabwe

In order to contribute to spider diversity distribution records within Zimbabwe, spiders were sampled at a mixed wildlife and cattle ranch using pitfall traps and sweep-netting. Sampling was conducted from June 2017 to April 2018. A total of 2328 spiders representing 25 families, 94 genera, and 166 species were recorded. The most species-rich families were Salticidae (33 spp.), followed by the Gnaphosidae (28 spp.) and Lycosidae (20 spp.), while eight families were represented by a single species. Pitfall traps accounted for 1857 individuals overall, with the ground-dwelling fauna dominated by Stenaelurillus guttiger (37.86% of the total abundance). Sweep-nets accounted for 471 individuals overall, with the grass-dwelling fauna dominated by Thyene thyenioides (15.29% of the total abundance). The most abundant functional group was the free-living ground-dwellers (n = 1809, 77.71%), followed by free-living plant-dwellers (n = 266, 11.43%) and orb-web builders (n = 186,
7.98%). The current study contributes to the knowledge of a megadiverse group of predatory arthropods in the region.

Conservation implications: Sampling and monitoring of rangelands is essential, as the former aids in the identification of new species not previously recorded, as well as increasing knowledge on the distribution of spider species, which if not adequately conserved could face significant threats to their survival even before their documentation.

Sebata, Sicelo, Charles R. Haddad, Moira J. FitzPatrick, & Stefan H. Foord. "Spiders (Arachnida: Araneae) of a wildlife and cattle savanna ranch in South-Western Zimbabwe." Koedoe [Online], 65.1 (2023): 7 pages. Web. 12 Mar. 2024