Leite, Luciana FerreiraGomez, Renato SantiagoFonseca, Matheus de CastroGomez, Marcus ViniciusGuatimosim, Cristina2014-10-012011Leite, Luciana Ferreira, Renato Santiago Gomez, Matheus de Castro Fonseca, Marcus Vinicius Gomez, and Cristina Guatimosim. 2011. “Effect of intravenous anesthetic propofol on synaptic vesicle exocytosis at the frog neuromuscular junction.” Acta Pharmacologica Sinica 32 (1): 31-37. doi:10.1038/aps.2010.175. http://dx.doi.org/10.1038/aps.2010.175.1671-4083http://nrs.harvard.edu/urn-3:HUL.InstRepos:12987290Aim: To investigate the presynaptic effects of propofol, a short-acting intravenous anesthetic, in the frog neuromuscular junction. Methods: Frog cutaneous pectoris nerve muscle preparations were prepared. A fluorescent tool (FM1-43) was used to visualize the effect of propofol on synaptic vesicle exocytosos in the frog neuromuscular junction. Results: Low concentrations of propofol, ranging from 10 to 25 μmol/L, enhanced spontaneous vesicle exocytosis monitored by FM1-43 in a Ca2+-dependent and Na+-independent fashion. Higher concentrations of propofol (50, 100, and 200 μmol/L) had no effect on spontaneous exocytosis. By contrast, higher concentrations of propofol inhibited the Na+-dependent exocytosis evoked by 4-aminopyridine but did not affect the Na+-independent exocytosis evoked by KCl. This action was similar and non-additive with that observed by tetrodotoxin, a Na+ channel blocker. Conclusion: Our data suggest that propofol has a dose-dependent presynaptic effect at the neuromuscular transmission which may help to understand some of the clinical effects of this agent on neuromuscular function.en-USpropofolneuromuscular junctionfrogFM1-43synaptic vesiclegeneral anestheticJournal Article2014-10-0110.1038/aps.2010.175