Toxins 2011, 3(2), 142-162; doi:10.3390/toxins3020142
Article

Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine) on the Central Nervous System of Rats

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Received: 18 January 2011; in revised form: 1 February 2011 / Accepted: 12 February 2011 / Published: 22 February 2011
(This article belongs to the Special Issue Spider Venoms)
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: The 6-hydroxytrypargine (6-HT) is an alkaloidal toxin of the group of tetrahydro-b-carbolines (THbC) isolated from the venom of the colonial spider Parawixia bistriata. These alkaloids are reversible inhibitors of the monoamine-oxidase enzyme (MAO), with hallucinogenic, tremorigenic and anxiolytic properties. The toxin 6-HT was the first THbC chemically reported in the venom of spiders; however, it was not functionally well characterized up to now. The action of 6-HT was investigated by intracerebroventricular (i.c.v.) and intravenous (i.v.) applications of the toxin in adult male Wistar rats, followed by the monitoring of the expression of fos-protein, combined with the use of double labeling immunehistochemistry protocols for the detection of some nervous receptors and enzymes related to the metabolism of neurotransmitters in the central nervous system (CNS). We also investigated the epileptiform activity in presence of this toxin. The assays were carried out in normal hippocampal neurons and also in a model of chronic epilepsy obtained by the use of neurons incubated in free-magnesium artificial cerebro-spinal fluid (ACSF). Trypargine, a well known THbC toxin, was used as standard compound for comparative purposes. Fos-immunoreactive cells (fos-ir) were observed in hypothalamic and thalamic areas, while the double-labeling identified nervous receptors of the sub-types rGlu2/3 and NMR1, and orexinergic neurons. The 6-HT was administrated by perfusion and ejection in “brain slices” of hippocampus, inducing epileptic activity after its administration; the toxin was not able to block the epileptogenic crisis observed in the chronic model of the epilepsy, suggesting that 6-HT did not block the overactive GluRs responsible for this epileptic activity.
Keywords: 6-hydroxytrypargine; fos protein; immunohistochemistry; hypothalamus; hippocampus; epilepsy; NMDA; neurotoxicity
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MDPI and ACS Style

Cesar-Tognoli, L.M.M.; Salamoni, S.D.; Tavares, A.A.; Elias, C.F.; Da Costa, J.C.; Bittencourt, J.C.; Palma, M.S. Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine) on the Central Nervous System of Rats. Toxins 2011, 3, 142-162.

AMA Style

Cesar-Tognoli LMM, Salamoni SD, Tavares AA, Elias CF, Da Costa JC, Bittencourt JC, Palma MS. Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine) on the Central Nervous System of Rats. Toxins. 2011; 3(2):142-162.

Chicago/Turabian Style

Cesar-Tognoli, Lilian M. M.; Salamoni, Simone D.; Tavares, Andrea A.; Elias, Carol F.; Da Costa, Jaderson C.; Bittencourt, Jackson C.; Palma, Mario S. 2011. "Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine) on the Central Nervous System of Rats." Toxins 3, no. 2: 142-162.

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