Fotografía Treknature [[- The Genus Phoneutria, Perty 1833, wandering spiders: These spiders belong to the family Ctenidae where Phoneutria is one of around 40 genus and the only one knowned that have a venom potent enough to be a danger to humans. The genus Phoneutria can be found over large parts of South America and some parts of Central America, and 5 species are described so far after a revision of the genus in 2001.
Phoneutria differs from other genus in the family Ctenidae by a thick comb of hairs on the lateral edge and ventral part of the pedipalps. Phoneutria also differs from other ctenids by its unique warning display -the body and the two first legpair are kept vertical and then the spider rock from side to side horizontally. The Venon: The most famous species is Phoneutria fera that in popular literature been dubbed as the most venomous spider in the world. Its open for debate if that is truly the case but fact is they got a very potent neurotoxin, just as nigriventer have. Most people that are bitten by a member of this family is bitten by a nigriventer, mostly because the species appear in heavily populated areas like Sao Paolo and Rio de Janiero while P. fera are found for most part in the Amazon region where the poulation is less dense. The research on Phoneutria venom is done on nigriventer and some believe that bites that been refered as fera bites most likely are in reality misidentified nigriventer bites and envenomations (pers. corr. Rogerio Bertani, Butantan Inst.). So how dangerous are nigriventer? Deaths have occured and during the years 1926-1996 14 fatalities happened. Nowadays there are a good working serum available in Brazil that are produced on Butantan Institute in Sao Paulo. The imidiate effects after a bite is intense local pain and swelling in the bite area, followed by serious systematic effects like irregular heart rythm, stoppage of the coagulare effects in the blood, priapism, lung edema and vomiting. One should never take a bite lightly despite the statistics that show that the risk of dying after a bite is quite small. If you are unlucky unpleasant effects and even death can be the result and one should be extra careful if serum is not regulary available. To give some idea of the potency of the venom the LD50 for nigriventer has shown to be 0.3 mg and for comparison in the same test showed 5.5 mg for black widow , Latrodectus mactans. Note that all LD50 results should be taken with a grain of salty so to speak. Conclusion: Phoneutria are nice and interesting spiders to keep in captivity, if you have a long experience in keeping fast and aggressive spiders. If not it is better to stay away from these genus because of the dangerous venom. They are easy to care for and demand not much except a big dose of common sence and much respect (Source: Minaxtarantulas) Link Treknature.]].
Otras investigaciones ya habían identificado el potencial de sustancias del veneno de la araña de las bananeras (Phoneutria nigriventer) para tratar problemas cerebrales y de erección.
Según Gomez, los investigadores de la Santa Casa de Belo Horizonte experimentaron con éxito el uso de neurotoxinas purificadas del veneno de la araña como agente terapéutico para tratar el dolor, la arritmia cardíaca y la isquemia cerebral.
«La toxina phkv, presente en el veneno de esta araña, inhibe las arritmias cardíacas atrial y ventricular«, aseguró el investigador en su testimonio.
«El uso de la toxina tx3-4 en experimentos mostró acción neuroprotectora; redujo la muerte de células del hipocampo y restableció la función de las neuronas afectadas por isquemia cerebral (derrame)«, agregó el especialista.
Gomez explicó que los experimentos fueron realizados a nivel preclínico, es decir con la inyección de las sustancias purificadas del veneno en ratones de laboratorio.
«Con la investigación obtuvimos formas recombinantes de las toxinas para posteriormente utilizarlas como agentes terapéuticos. Una de las toxinas puede ser útil para el combate al dolor de pacientes con cáncer o con sida en los casos de intolerancia a morfina«, aseguró.
Diferentes investigadores brasileños trabajan hace más de dos décadas en el análisis de las sustancias del veneno de la araña de las bananeras y ya han conseguido aislar, purificar y sintetizar diferentes toxinas de la misma con uso medicinal.
Además de propiedades para tratar el dolor, la isquemia cerebral, las arritmias cardíacas, y la protección de las neuronas y de las células del sistema nervioso, otras sustancias del veneno vienen siendo analizadas por su capacidad de transmisión de impulsos nerviosos y su acción sobre los músculos de los vasos sanguíneos y del intestino.
Las investigaciones demostraron que dos de las toxinas (Tx2-5 y Tx2-6) tienen capacidad para provocar el priapismo (erección del pene) y pueden ser usadas para desarrollar medicinas contra la impotencia sexual.
broadtrix 08 de octubre de 2008
TarantulasTubeWorld 22 de julio de 2008: Nome científico: Phoneutria nigriventer Nome comum: Aranha Armadeira Esta espécie e dada como a mais agressiva do mundo, ergue-se apoiada sobre as patas traseiras e salta sobre o agressor, que muitas vezes é atacado sem saber. Costuma viver em locais onde existem bananeiras, lenhas, telhas e tijolos empilhados e terrenos baldios. Tem hábitos noturnos e não tem moradia fixa podendo entrar dentro de casas e, ao amanhecer, abrigar-se em sapatos e botas, causando acidentes quando são vestidos. Seu veneno tem ação neurotóxico, é extremamente dolorido e pode levar a vítima ao «estado de choque», e até a morte quando se trata de crianças pequenas e pessoas de idade. Os adultos que suportam a dor recebem tratamento local com anestésicos e anti-histamínicos. Casos mais graves necessitam soroterapia e acompanhamento médico.
Rafasuttispider 21 de abril de 2008: Aranha Armadeira (Phoneutria nigriventer) atacando.
(27 febrero 2010)
