Despite Tityus bahiensis being one of the most dangerous scorpions in Brazil, there are few studies about the effects of its venom, which acts mainly on the central nervous system. Previous studies demonstrated the convulsive ability of this venom. The present work aimed to study the hippocampal effects in rats of some toxins isolated from pool V, which induces a pronounced epileptogenic effect. The pool was separated by reverse-phase HPLC, and the peaks with higher yield (Tb V-1, V-5, V-24, V-27, and V-28) were used in the experiments. Cannulae and electrodes were implanted in the hippocampus of male Wistar rats (240–250？g). The animals were divided into six groups that received intracerebral injection of toxin solution (1 or 2？μg/μL) or Ringer solution (control group), and they were submitted to behavioral, electrographic, and histological analysis. All toxins studied evoked electrographic and behavioral epileptic-like activity to different degrees. Moreover, the toxins V-1, V-24, and V-28 caused significant neuronal loss in CA4 ipsi- and contralateral hippocampal areas. These results suggest that toxins from T. bahiensis scorpion, when injected into the hippocampus, are able to act directly on the central nervous system inducing convulsive and neurodegenerative effects. 1. Introduction From an epidemiological viewpoint, the scorpion family Buthidae is considered to be the most important among the 19 families distributed in the world [1]. Twenty-five species dangerous to humans belong to this family. In Brazil, scorpions from the genus Tityus, which belong to this family, represent about 60% of the neotropical fauna [2], and the most important species are Tityus serrulatus, T. bahiensis, T. stigmurus, and T. obscurus [3]. The purification and sequencing of toxin from T. bahiensis were initially done by Becerril et al. [4], who compared them with toxins from T. serrulatus and observed that the most abundant peptide from this scorpion (named γ-bahiensis) is 95% identical to toxin γ from the venom of Tityus serrulatus. Other toxins have already been isolated, such as III-8 bahiensis (III-8b), TbTx-VI, and IV-5 bahiensis (IV-5b), which show 80% homology with toxin IV-5 from T. serrulatus [5]. Meanwhile, there are few papers focusing on the purification, sequencing, mechanisms of action, and effects of toxins that comprise this venom [4–7]. In spite of the large number of studies in the literature as revised by Cologna et al. [3], the central effects of toxins and venoms have been neglected due to the common understanding that these peptides do not cross
References
[1]
L. Prendini and W. C. Wheeler, “Scorpion higher phylogeny and classification, taxonomic anarchy, and standards for peer review in online publishing,” Cladistics, vol. 21, no. 5, pp. 446–494, 2005.
[2]
FUNASA, Manual de Diagnostico e Tratamento de Acidentes por Animais Pe？onhentos, Funda？？o Nacional de Saúde, Brasília, Brazil, 2nd edition, 2001.
[3]
C. T. Cologna, S. Marcussi, J. R. Giglio, A. M. Soares, and E. C. Arantes, “Tityus serrulatus scorpion venom and toxins: an overview,” Protein and Peptide Letters, vol. 16, no. 8, pp. 920–932, 2009.
[4]
B. Becerril, S. Marangoni, and L. D. Possani, “Toxins and genes isolated from scorpions of the genus Tityus,” Toxicon, vol. 35, no. 6, pp. 821–835, 1997.
[5]
C. Trequattrini, F. Z. Zamudio, A. Petris, G. Prestipino, L. D. Possani, and F. Franciolini, “Tityus bahiensis toxin IV-5b selectively affects Na channel inactivation in chick dorsal root ganglion neurons,” Comparative Biochemistry and Physiology A, vol. 112, no. 1, pp. 21–28, 1995.
[6]
G. A. Louren？o, I. Lebrun, and V. A. C. Dorce, “Neurotoxic effects of fractions isolated from Tityus bahiensis scorpion venom (Perty, 1834),” Toxicon, vol. 40, no. 2, pp. 149–157, 2002.
[7]
L. T. T. Ossanai, G. A. Louren？o, A. L. A. Nencioni, I. Lebrun, N. Yamanouye, and V. A. C. Dorce, “Effects of a toxin isolated from Tityus bahiensis scorpion venom on the hippocampus of rats,” Life Science, vol. 91, no. 7-8, pp. 230–236, 2012.
[8]
M. Ismail, O. H. Osman, K. A. Gumaa, and M. A. Karrar, “Some pharmacological studies with scorpion Pandinus exitialis venom,” Toxicon, vol. 12, no. 1, pp. 75–82, 1974.
[9]
M. P. Revelo, E. A. Bambirra, A. P. Ferreira, C. R. Diniz, and C. Chávez-Olórtegui, “Body distribution of Tityus serrulatus scorpion venom in mice and effects of scorpion antivenom,” Toxicon, vol. 34, no. 10, pp. 1119–1125, 1996.
[10]
P. A. Guidine, T. Moraes-Santos, A. R. Massensini, and M. F. Moraes, “Carbamazepine protects the CNS of Wistar rats against the central effects of scorpion envenomation,” Neurotoxicology, vol. 29, no. 1, pp. 136–142, 2008.
[11]
O. Clot-Faybesse, R. Guieu, H. Rochat, and C. Devaux, “Toxicity during early development of the mouse nervous system of a scorpion neurotoxin active on sodium channels,” Life Sciences, vol. 66, no. 3, pp. 185–192, 2000.
[12]
E. A. Nunan, M. F. Moraes, V. N. Cardoso, and T. Moraes-Santos, “Effect of age on body distribution of Tityustoxin from Tityus serrulatus scorpion venom in rats,” Life Sciences, vol. 73, no. 3, pp. 319–325, 2003.
[13]
P. A. Guidine, M. B. Mesquita, T. Moraes-Santos, A. R. Massensini, and M. F. Moraes, “Electroencephalographic evidence of brainstem recruitment during scorpion envenomation,” Neurotoxicology, vol. 30, no. 1, pp. 90–96, 2009.
[14]
A. L. A. Nencioni, G. A. Louren？o, I. Lebrun, J. C. Florio, and V. A. C. Dorce, “Central effects of Tityus serrulatus and Tityus bahiensis scorpion venoms after intraperitoneal injection in rats,” Neuroscience Letters, vol. 463, no. 3, pp. 234–238, 2009.
[15]
G. Paxinos and C. Watson, The Rat Brain in Stereotaxic Coordinates, Academic Press, San Diego, Calif, USA, 4th edition, 1998.
[16]
D. A. McCormick and D. Contreras, “On the cellular and network bases of epileptic seizures,” Annual Review of Physiology, vol. 63, pp. 815–846, 2001.
[17]
R. C. R. de la Vega and L. D. Possani, “Overview of scorpion toxins specific for Na+ channels and related peptides: biodiversity, structure-function relationships and evolution,” Toxicon, vol. 46, no. 8, pp. 831–844, 2005.
[18]
M. A. Romano-Silva, M. V. Gomez, and M. J. Brammer, “Modulation of Ca2+-stimulated glutamate release from synaptosomes by Na+ entry through tetrodotoxin-sensitive channels,” Biochemical Journal, vol. 304, no. 2, pp. 353–357, 1994.
[19]
M. V. Gomez, M. A. Romano-Silva, and M. A. M. Prado, “Effects of tityustoxin on central nervous system,” Toxin Reviews, vol. 14, no. 3, pp. 437–456, 1995.
[20]
A. R. Massensini, M. A. Romano-Silva, and M. V. Gomez, “Sodium channel toxins and neurotransmitter release,” Neurochemical Research, vol. 28, no. 10, pp. 1607–1611, 2003.
[21]
A. L. A. Nencioni, I. Lebrun, and V. A. C. Dorce, “A microdialysis study of glutamate concentration in the hippocampus of rats after TsTX toxin injection and blockade of toxin effects by glutamate receptor antagonists,” Pharmacology Biochemistry and Behavior, vol. 74, no. 2, pp. 455–463, 2003.
[22]
Z. Kleinrok and L. Turski, “Kainic acid-induced wet dog shakes in rats. The relation to central neurotransmitters,” Naunyn-Schmiedeberg's Archives of Pharmacology, vol. 314, no. 1, pp. 37–46, 1980.
[23]
K. C. Fone, A. J. Robinson, and C. A. Marsden, “Characterization of the 5-HT receptor subtypes involved in the motor behaviours produced by intrathecal administration of 5-HT agonists in rats,” British Journal of Pharmacology, vol. 103, no. 2, pp. 1547–1555, 1991.
[24]
E. J. Shin, H. J. Jeong, Y. H. Chung et al., “Decrease in the kainate-induced wet dog shake behavior in genetically epilepsy-prone rats: possible involvement of an impaired synaptic transmission to the 5-HT2A receptor,” Journal of Pharmacological Sciences, vol. 110, no. 3, pp. 401–404, 2009.
[25]
B. A. Ellenbroek and A. R. Cools, “Apomorphine susceptibility and animal models for psychopathology: genes and environment,” Behavior Genetics, vol. 32, no. 5, pp. 349–361, 2002.
[26]
P. J. F. Martins, J. N. Nobrega, S. Tufik, and V. D'Almeida, “Sleep deprivation-induced gnawing—relationship to changes in feeding behavior in rats,” Physiology & Behavior, vol. 93, no. 1-2, pp. 229–234, 2008.
[27]
A. E. Yankovsky, F. Andermann, and F. Dubeau, “Post-ictal forceful yawning in a patient with nondominant hemisphere epilepsy,” Epileptic Disorders, vol. 8, no. 1, pp. 65–69, 2006.
[28]
F. Sanna, S. Succu, M. R. Melis, and A. Argiolas, “Dopamine agonist-induced penile erection and yawning: differential role of D2-like receptor subtypes and correlation with nitric oxide production in the paraventricular nucleus of the hypothalamus of male rats,” Behavioural Brain Research, vol. 230, no. 2, pp. 355–364, 2012.
[29]
O. Walusinski, “Yawning in diseases,” European Neurology, vol. 62, no. 3, pp. 180–187, 2009.
[30]
J. N. Caviness, “Myoclonus,” Parkinsonism and Related Disorders, vol. 13, no. 3, pp. S375–S384, 2007.
[31]
I. M. Concei？？o, I. Lebrun, M. Cano-Abad et al., “Synergism between toxin-γ from Brazilian scorpion Tityus serrulatus and veratridine in chromaffin cells,” The American Journal of Physiology—Cell Physiology, vol. 274, no. 6, pp. C1745–C1754, 1998.
[32]
I. M. Concei？？o, A. Jurkiewicz, D. R. Fonseca et al., “Selective release of ATP from sympathetic nerves of rat vas deferens by the toxin TsTX-I from Brazilian scorpion Tityus serrulatus,” British Journal of Pharmacology, vol. 144, no. 4, pp. 519–527, 2005.
[33]
A. L. A. Nencioni, F. F. Carvalho, I. Lebrun, V. A. C. Dorce, and M. R. L. Sandoval, “Neurotoxic effects of three fractions isolated from Tityus serrulatus scorpion venom,” Pharmacology and Toxicology, vol. 86, no. 4, pp. 149–155, 2000.
[34]
V. F. Teixeira, I. M. Concei？？o, I. Lebrun, A. L. A. Nencioni, and V. A. C. Dorce, “Intrahippocampal injection of TsTX-I, a beta-scorpion toxin, causes alterations in electroencephalographic recording and behavior in rats,” Life Sciences, vol. 87, no. 15-16, pp. 501–506, 2010.
[35]
E. W. Lothman, E. H. Bertram III, and J. L. Stringer, “Functional anatomy of hippocampal seizures,” Progress in Neurobiology, vol. 37, no. 1, pp. 1–82, 1991.
[36]
Y. Isomura, Y. Fujiwara-Tsukamoto, and M. Takada, “A network mechanism underlying hippocampal seizure-like synchronous oscillations,” Neuroscience Research, vol. 61, no. 3, pp. 227–233, 2008.
[37]
G. Zimmerman, M. Njunting, S. Ivens et al., “Acetylcholine-induced seizure-like activity and modified cholinergic gene expression in chronically epileptic rats,” European Journal of Neuroscience, vol. 27, no. 5, pp. 965–975, 2008.
[38]
G. D. Hilton, J. L. Nunez, L. Bambrick, S. M. Thompson, and M. M. McCarthy, “Glutamate-mediated excitotoxicity in neonatal hippocampal neurons is mediated by mGluR-induced release of Ca2+ from intracellular stores and is prevented by estradiol,” European Journal of Neuroscience, vol. 24, no. 11, pp. 3008–3016, 2006.
[39]
H. E. Scharfman, “The neurobiology of epilepsy,” Current Neurology and Neuroscience Reports, vol. 7, no. 4, pp. 348–354, 2007.
[40]
G. D'Suze, S. Moncada, C. González, C. Sevcik, V. Aguilar, and A. Alagón, “Relationship between plasmatic levels of various cytokines, tumour necrosis factor, enzymes, glucose and venom concentration following Tityus scorpion sting,” Toxicon, vol. 41, no. 3, pp. 367–375, 2003.
[41]
Y. D. Fukuhara, M. L. Reis, R. Dellalibera-Joviliano, F. Q. Cunha, and E. A. Donadi, “Increased plasma levels of IL-1β, IL-6, IL-8, IL-10 and TNF-α in patients moderately or severely envenomed by Tityus serrulatus scorpion sting,” Toxicon, vol. 41, no. 1, pp. 49–55, 2003.
[42]
V. L. Petricevich, “Cytokine and nitric oxide production following severe envenomation,” Current Drug Targets: Inflammation and Allergy, vol. 3, no. 3, pp. 325–332, 2004.
[43]
M. Sch？fers and L. Sorkin, “Effect of cytokines on neuronal excitability,” Neuroscience Letters, vol. 437, no. 3, pp. 188–193, 2008.
[44]
A. Vezzani, S. Balosso, and T. Ravizza, “The role of cytokines in the pathophysiology of epilepsy,” Brain, Behavior, and Immunity, vol. 22, no. 6, pp. 797–803, 2008.
[45]
D. G. Fujikawa, S. S. Shinmei, and B. Cai, “Kainic acid-induced seizures produce necrotic, not apoptotic, neurons with internucleosomal DNA cleavage: implications for programmed cell death mechanisms,” Neuroscience, vol. 98, no. 1, pp. 41–53, 2000.
[46]
D. C. McIntyre and K. L. Gilby, “Mapping seizure pathways in the temporal lobe,” Epilepsia, vol. 49, no. 3, pp. 23–30, 2008.
[47]
M. P. Witter and D. G. Amaral, “Hippocampal formation,” in The Rat Nervous System, G. Paxinos, Ed., pp. 635–704, Elsevier, New York, NY, USA, 3rd edition, 2004.
[48]
G. Perea and A. Araque, “Communication between astrocytes and neurons: a complex language,” Journal of Physiology-Paris, vol. 96, no. 3-4, pp. 199–207, 2002.
[49]
M. Tsacopoulos, “Metabolic signaling between neurons and glial cells: a short review,” Journal of Physiology-Paris, vol. 96, no. 3-4, pp. 283–288, 2002.
