[Blocking effects of dimethoate on acetylcholine receptor channels].
The patch-clamp technique was used to study the inhibitory effect of dimethoate, an organophosphrous pesticide, on the membrane of embryoinc Xenopus musle cells in culture. Using whole-cell clamp and cell-attached clamp, we found that the direct inhibitory effects of dimethoate was evidenced on both miniature end-plate currents (MEPC) and single channel currents. Dimethoate increased the amplitude and frequency of MEPC at a lower concentration (21.6 mumol/L) while both decreased at a higher concentration (237 mumol/L). The dimethoate at a concentration of 146 mumol/L shortened the opening time and decreased the opening probability of the single channel. The results show that dimethoate is an AChR channel blocker.
D000818:Animals; D004117:Dimethoate / Q000633:toxicity*; D007306:Insecticides / Q000633:toxicity*; D009469:Neuromuscular Junction / Q000187:drug effects; D018408:Patch-Clamp Techniques; D011950:Receptors, Cholinergic / Q000187:drug effects*; D014982:Xenopus laevis