A anticonvulsive fraction from Scaptocosa raptoria (Araneae: Lycosidae) spider venom.
Several spider neurotoxins are known to show highly selective effects on nervous tissues. Intracerebral injection into rats of spider venom from Scaptocosa raptoria, prevents seizures induced by convulsant agents. Injection of phenytoin (390 pmol/200 nl), muscimol (90 pmol/200 nl), baclofen (500 pmol/200 nl) into the substantia nigra (SN) pars reticulata, protected rats from convulsions evoked by unilateral focal injection of bicuculline into the area tempestas by 50, 80, and 100%, respectively. Denatured S. raptoria crude venom (4.6 microg, 2.3 microg, and 920 ng/200 nl), when administered into the SN, prevented seizures elicited by bicuculline in the area tempestas by 100, 100, and 87.5%, respectively. The injection into the SN of 160 ng/200 nl of fraction SrTx1 isolated from S. raptoria venom, reduced the magnitude of seizures. This fraction was rechromatographed affording fractions SrTx1.1, SrTx1.2 and SrTx1.3, and they were administered into the SN at doses of 100, 200, and 400 ng/200 nl respectively. Fraction SrTx1.3 protected 50, 85.7, and 100% of the animals against the seizures elicited by bicuculline injected into the area tempestas. This suggests that S. raptoria venom as well as its SrTx1.3 fraction, might be potential sources of new anticonvulsant drugs.
Mussi-Ribeiro
Alessandra
A
Neurobiology and Venoms Laboratory, Department of Biology, Faculty of Philosophy, Sciences and Literature of Ribeirão Preto, University of Sao Paulo, Sao Paulo SP 14040-901, Brazil.
Miranda
Antonio
A
Gobbo-Netto
Leonardo
L
Peporine Lopes
Norberto
N
dos Santos
Wagner Ferreira
WF
D000818:Animals; D000927:Anticonvulsants / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000517:prevention & control*; D013111:Spider Venoms / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D013378:Substantia Nigra / Q000187:drug effects / Q000502:physiology
D000927:Anticonvulsants; D013111:Spider Venoms