PhTx3-4, a Spider Toxin Calcium Channel Blocker, Reduces NMDA-Induced Injury of the Retina

作者：Binda Nancy Scardua; Petruceli Carayon Charles Porto; Agostini Rafael Mourao; do Nascimento Pinheiro Ana Cristina; Cordeiro Marta Nascimento; Romano Silva Marco Aurelio; Silva Juliana Figueira; Rita Pereira Elizete Maria; da Silva Junior Claudio Antonio; de Castro Junior Celio Jose; Sena Guimaraes Andre Luiz; Gomez Marcus Vinicius^*

来源：Toxins, 2016, 8(3): 70.

DOI：10.3390/toxins8030070

• Neuroprotection
• PhTx3-4
• retina
• phoneutria nigriventer
• spider toxins

The in vivo neuroprotective effect of PhTx3-4, a spider toxin N-P/Q calcium channel blocker, was studied in a rat model of NMDA-induced injury of the retina. NMDA (N-Methyl-d-Aspartate)-induced retinal injury in rats reduced the b-wave amplitude by 62% +/- 3.6%, indicating the severity of the insult. PhTx3-4 treatment increased the amplitude of the b-wave, which was almost equivalent to the control retinas that were not submitted to injury. The PhTx3-4 functional protection of the retinas recorded on the ERG also was observed in the neuroprotection of retinal cells. NMDA-induced injury reduced live cells in the retina layers and the highest reduction, 84%, was in the ganglion cell layer. Notably, PhTx3-4 treatment caused a remarkable reduction of dead cells in the retina layers, and the highest neuroprotective effect was in the ganglion cells layer. NMDA-induced cytotoxicity of the retina increased the release of glutamate, reactive oxygen species (ROS) production and oxidative stress. PhTx3-4 treatment reduced glutamate release, ROS production and oxidative stress measured by malondialdehyde. Thus, we presented for the first time evidence of in vivo neuroprotection from NMDA-induced retinal injury by PhTx3-4 (-ctenitoxin-Pn3a), a spider toxin that blocks N-P/Q calcium channels.

• 出版日期2016-3