EN
Patch-clamp technique was used to examine effect of trimethyllead chloride (Met3PbCl) on the SV channel activity in the red beet (Beta vulgaris L.) taproot vacuoles. It was found that in the control bath macroscopic currents showed typical slow activation and strong outward rectification of the steady-state currents. The addition of Met3PbCl to the bath solution blocked in a concentration-dependent manner SV currents in red beet vacuoles. The time constant, τ, increased several times in the presence of 100 μM trimethyllead chloride at all voltages tested. Trimethyllead chloride decreased significantly (by about one order of magnitude) the open probability of single channels. The recordings of single channel activity obtained in the presence and in the absence of Met3PbCl showed that organolead only slightly (by ca. 10%) decreased the unitary conductance of single channels. It was also found that Met3PbCl diminished significantly the number of SV channel openings, whereas it did not change the opening times of the channels. Within the present work the existence of spatial correlation beetwen ion channels of Beta vulgaris vacuolar membrane was shown. Moreover, the comparison of data collected in the control and in the presence of trimethyllead shows that organolead compound disturb not only the ion transport through the membrane, but also spacial correlations among channels. This work was supported by the KBN grant N305 336434