Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/75119
Type: Artigo de periódico
Title: The effect of Phoneutria nigriventer (armed spider) venom on arterial blood pressure of anaesthetised rats
Author: Costa, SKP
Moreno, H
Brain, SD
DeNucci, G
Antunes, E
Abstract: The changes induced in the mean arterial blood pressure of anaesthetised rats following the administration of armed spider (Phoneutria nigrinventer) venom have been investigated. The intravenous injection of Phoneuhria nigriventer venom (0.1 mg/kg) evoked a brief and reversible decrease in the mean arterial blood pressure whereas a higher dose of venom (0.3 mg/kg) caused a biphasic response characterized by a short-lasting hypotension followed by a sustained and prolonged hypertension (40-50 min). These changes were accompanied by tachycardia, salivation, fasciculations, defecation and respiratory disturbances. Pretreatment of the animals with atropine (10 mg/kg), propranolol (100 mg/kg), phenoxybenzamine (100 mg/kg) and indomethacin (4 mg/kg) did not significantly affect the mean arterial blood pressure changes induced by Phoneutria nigriventer venom. Similarly, the bradykinin B-2 receptor antagonist Hoe 140 (D-Arg-[Hyp(3),Thi(5),DTic(7),Oic(8)]-bradykinin (0.6 mg/kg), the PAF receptor antagonist WEB 2086 (3-(4-(2-chlorophenyl)-9-methyl-6 H-thieno-(3,2f) (1,2,4)-triazolo-(4,3-a) (1,4)aiazepine-2-yl)-(4-morpholinyl)-1-propanone) (20 mg/kg), the tachykinin NK2 receptor antagonist SR 140333 ((S)1-(2-[3-(3,4-dichlorophenyl)-1-(3-iso-propoxyphenyl acetyl) piperidin-3-yl] ethyl)-4-phenyl-1-azoniabicyclo[2.2.2] octane, chloride) (0.5 mg/kg), the tachykinin NK2 receptor antagonist SR 48968 ((S)-N-methyl-N[4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-d (0.5 mg/kg) and the nitric oxide synthase inhibitor N-omega-nitro-L-arginine methyl ester (10 mg/kg) had no significant effect on the mean arterial blood pressure changes induced by Phoneutria nigriventer venom. The increase in the blood pressure induced by Phoneutria nigriventer venom was also not significantly affected by either the angiotensin II receptor antagonist losartan (10 mg/kg) or the endothelin ET(A) receptor antagonist FR 139317 ((R)2-[(R)-2-[[1(hexahydro-1H-azepinyl]carbonyl]amino-4-methyl-pentanoyl[amino-3-[3-(1-methyl-1H-indoyl)lpropionyl] amino-3-(2-pyridyl) propionic acid) (30 mg/kg). The ATP-dependent K+ channel antagonist glibenclamide (50 mg/kg) reduced by 40% the hypotension induced by Phoneutria nigriventer venom without affecting the hypertensive response. Pretreatment of the animals with L-type Ca2+ channel antagonists such as verapamil (10-100 mu g/kg/min), diltiazem (40-120 mu g/kg/min) and nifedipine (0.3-10 mg/kg) markedly attenuated the hypertension induced by Phoneutria nigriventer venom. Verapamil (30 mu g/kg/min) and diltiazem (120 mu g/kg/min) also promptly reversed the established hypertension induced by Phoneutria nigriventer venom when infused 8 min after venom injection. Our results indicate that the brief decrease of blood pressure induced by Phoneutria nigriventer venom.is partially due to ATP-dependent K+ channel activation. The prolonged hypertension seems to result from direct Ca2+ entry into vascular and/or cardiac muscles.
Subject: spider venom
Ca2+ channel blocker
K+ channel blocker
endothelin-1
nitric oxide (NO)
Hoe 140
Country: Holanda
Editor: Elsevier Science Bv
Rights: fechado
Identifier DOI: 10.1016/0014-2999(95)00739-3
Date Issue: 1996
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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