[Lead inhibits proton gated currents (ASIC) in dorsal root ganglion neurons].
BACKGROUND
Acid sensing ion channels (ASIC) are ionic channels activated by transient pH reductions in the ext raceilularenvi ronment. Although the activation mechanism is not fully elucidated, it is clear that the channel is activated by proton binding to its extraceilular domain, a process that is modulated by calcium and zinc.


OBJECTIVE
The fact that divalent cations are able to modify ASIC operation, lead us to consider if lead, anotherdivalent cation and widely distributed neurotoxicant, is also capable to affect ASIC function.


METHODS
For this purpose, we recordedASiC currents in rat dorsal root ganglion neurons using the whole cell patch-clamp technique.


RESULTS
The results indicated that lead inhibits ASIC currents in a concentration -dependent fashion.


CONCLUSIONS
These results contribute to the understanding of the activation mechanism of ASIC and to explain some of the toxic mechanisms of lead in the organism.
Garza-Carbajal
Aníbal
A
Laboratorio de Neurofisiología Sensorial, Instituto de Fisiología, Universidad Autónoma de Puebla, Pue., México. anibalgar@gmail.com
D062565:Acid Sensing Ion Channels; D000818:Animals; D005727:Ganglia, Spinal / Q000187:drug effects* / Q000503:physiopathology; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D008565:Membrane Proteins / Q000187:drug effects* / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000187:drug effects* / Q000502:physiology; D009942:Organometallic Compounds / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D015222:Sodium Channels / Q000187:drug effects* / Q000502:physiology
D062565:Acid Sensing Ion Channels; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D009942:Organometallic Compounds; D015222:Sodium Channels; C008261:lead acetate