Acetylcholine release from rat brain cortical slices evoked by the fraction P4 of the venom of the spider Phoneutria nigriventer has Ca2+ and temperature independent components.
Fractionation of the venom of the spider Phoneutria nigriventer revealed that it was a mixture of several neurotoxic peptides. The peptides so far characterized either inhibited or induced neurotransmitter release. These effects were mediated by Ca2+ channels or increasing Na+ permeability through voltage sensitive Na(+)-channels, respectively. The pooled toxic components (fraction P4) showed stimulatory effects on acetylcholine release from brain cortical slices. In addition, a component of the observed effects resembling that of alpha-latrotoxin was identified, which was characterized by the ability to provoke release of acetylcholine (ACh) at low temperature and in a manner independent of extracellular Ca2+ and of voltage sensitive Na(+)-channels.
Romano-Silva
M A
MA
Laboratório de Neurofarmacologia-Departamento de Farmacologia, ICB Universidade Federal de Minas Gerais, Belo Horizonte-MG, Brazil. mromano@icb.ufmg.br
Gomez
M V
MV
Diniz
C R
CR
Cordeiro
M N
MN
Ribeiro
A M
AM
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000502:physiology*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D005591:Chemical Fractionation; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D051381:Rats; D013111:Spider Venoms / Q000494:pharmacology*; D013696:Temperature; D013779:Tetrodotoxin / Q000494:pharmacology
D013111:Spider Venoms; D013779:Tetrodotoxin; D000109:Acetylcholine; D002118:Calcium