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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