PhTx-2

PhTx-2 is a toxic fraction of the venom of the Brazilian wandering spider Phoneutria nigriventer.

Target

This fraction is responsible for most of the venom's effects, acts on voltage-gated ion channels, this fraction is composed of nine different peptides, of which PhTx-2-5 and PhTx-2-6 activate voltage-gated ion channels.^[1] PhTx-2 has been shown to be related to the activation and delay of inactivation of neuronal sodium channels, leading to an increase in the concentration of neuronal Ca++ and the release of glutamate, resulting in the release of neurotransmitters such as acetylcholine and catecholamines.^[2] Primates are more sensitive to the PhTx-1 & 2 components than in the case of mice, about 4 to 5 times more sensitive. The LD50 for a 70kg adult human is 6.3 mg, but the spider has only 1-2 mg and usually delivers 0.4 mg.

References

^ Fernanber (2013-04-30). TOXINOLOGIA CLINICA. LESIONES POR PICADURAS Y MORDEDURAS DE ANIMALES (in Spanish). Bubok. ISBN 978-84-686-3691-7.
^ Weiss, Marcelo Barros; Paiva, Jorge Wilson Souza (2018-10-10). Acidentes com Animais Peçonhentos (in Brazilian Portuguese). Thieme Revinter Publicações LTDA. ISBN 978-85-5465-084-1.

[1] Fernanber (2013-04-30). TOXINOLOGIA CLINICA. LESIONES POR PICADURAS Y MORDEDURAS DE ANIMALES (in Spanish). Bubok. ISBN 978-84-686-3691-7.

[2] Weiss, Marcelo Barros; Paiva, Jorge Wilson Souza (2018-10-10). Acidentes com Animais Peçonhentos (in Brazilian Portuguese). Thieme Revinter Publicações LTDA. ISBN 978-85-5465-084-1.

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