Differential effects of perhydrohistrionicotoxin on neurally and iontophoretically evoked endplate currents.
AUTOR(ES)
Albuquerque, E X
RESUMO
Perhydrohistrionicotoxin, at concentrations of 10(-12)-10(-7) M, depressed the current generated by iontophoretic application of acetylcholine to endplate regions of soleus and extensor digitorum longus muscles of rats. However, no changes in the amplitude or time course of spontaneous miniature endplate potentials or currents were seen with these concentrations of toxin. Evoked endplate currents were also unaffected by the toxin. Similarly, the responses to iontophoretic acetylcholine were depressed by these concentrations of perhydrohistrionicotoxin in chronically denervated muscles. Depression of responses in both normal and chronically denervated muscles developed gradually, was greater at higher concentrations, and was reversible. The different effects of the toxin on neurally evoked currents and currents produced by iontophoretic application of acetylcholine raise the possibility of the existence of two different population of receptor complexes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=411521Documentos Relacionados
- Accounting for the shapes and size distributions of miniature endplate currents.
- Acetylcholine receptor site density affects the rising phase of miniature endplate currents.
- Diffusion and binding constants for acetylcholine derived from the falling phase of miniature endplate currents.
- Spontaneous and uniquantal-evoked endplate currents in normal frogs are indistinguishable.
- Cat ventricular muscle treated with D600: effects on calcium and potassium currents.
