Distinct pathophysiological mechanisms of Heterometrus laoticus and Lychas mucronatus scorpion venoms on cardiovascular and renal functions

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  Distinct pathophysiological mechanisms of Heterometrus laoticus and Lychas mucronatus scorpion venoms on cardiovascular and renal functions Abstract Background:    Heterometrus laoticus and Lychas mucronatus are widely distributed in Southeast Asia, yet their pathophysiological effects of both venoms remain poorly characterized due to low human fatality rates. This study compared their venom compositions and acute cardiovascular and renal effects. Methods:   Anesthetized male New Zealand White rabbits were monitored for blood pressure (BP), heart rate (HR), and renal clearance following intravenous administration of crude venom (0.5 mg/kg). Venom components were identified via LC-MS/MS, and hematological/biochemical parameters were assessed. Results:    H. laoticus venom induced a rapid, transient hypotension ( p < 0.05), followed by a mild, prolonged hypotensive phase (up to 120 min). Conversely, L. mucronatus venom elicited a biphasic response: ...

Diversification of Dolichothele mottai (Araneae: Theraphosidae), a Cerrado endemic tarantula

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Diversification of Dolichothele mottai (Araneae: Theraphosidae), a Cerrado endemic tarantula

Abstract

The Cerrado is a savannah domain occurring along the Central Brazilian Plateau and is a biodiversity hotspot. Two main hypotheses have been suggested in the study of lineage diversification in this domain. The first suggests that Pleistocene climatic fluctuations isolated populations of species in refugia, leading to their diversification. The second considers geomorphological or ecological processes in the Neogene as the main drivers of diversification in the Cerrado. Here, the first phylogeographical study of a Cerrado endemic spider, Dolichothele mottai, was conducted to test these diversification hypotheses, using genomic and mitochondrial data combined with tests of demographic models. Dolichothele mottai lineages diversified in the Mio-Pliocene, and a pattern of east–west genetic structuring along Central Cerrado plateaus was identified. Vicariance was the preferred model in demographic analysis, and geomorphological events in the Araguaia River Valley region during the Mio-Pliocene might have been relevant to the evolutionary history of this species. However, owing to demographic analyses, the influence of Pleistocene processes cannot be discarded as a possible hypothesis to explain lineage diversification in this species. Diversification patterns inferred here are concomitant with other Central Cerrado animal lineages, suggesting that processes in the Neogene influenced the diversification of phylogenetically distant groups.

Vespasiano, C. T., Serino-Silva, C., Machado Silveira, G. P., Rodrigues, F. S., Rameh-de-Albuquerque, L. C., Sant'anna, S. S., Grego, K. F., & Tanaka-Azevedo, A. M. (2025). Investigating the Influence of Hepatic Neoplasms on Bothrops Venom Biochemistry. Toxicon, 108561. https://doi.org/10.1016/j.toxicon.2025.108561