Chloride flux assay

Chloride flux assay. Synaptic vesicles were prepared from brains of male ICR gice (20-30 g Blue Spruce Farms, Altamont, NY) (15) Assays of °C1 uptake involved preincubation (10-20 min) of vesicles with carrier solvent (ethanol or acetone, 0.5-1 yl) or insecticide, followed by incubation (4 sec) with bCl with or without GABA or added insecticides and isolation of labelled vesicles by rapid vacuum filtration. Detailed descriptions of the assay are published elsewhere ( 15,1 7) Abamectin stock solutions were prepared in absolute ethanol in silanized glass vials Abamectin in ethanol (1 yl) was added to give concentrations of 3 nM-3 yM in a final volume of 200 yl of vesicle suspension during preincubation or 3 yM in a final volume of 200 yl of bCl uptake medium. 

Recent studies have grouped lindane with the cyclodienes on the basisLjaf its potent and stereospecific inhibition of [3H]DHPTX (.2,3) and [3DS]TBPS (4 J>) binding. However, the quantitative correlations between potency in the chloride flux assay, potency in the [3 >S]TBPS binding assay, and acute toxicity that were observed for the cyclodienes do not extend to lindane. Lindane was a very weak inhibitor of chloride uptake (I 1 mM J7). Inclusion of the data... 

Figure 3. Correlation by least squares linear regression of inhibitory potencies in [ 5S]TBPS binding assays (4) with inhibitory potencies in chloride flux assays (1 5, 17) for seven cyclodienes. The data point for lindane is also shown but not included in the calculated regression. Redrawn from Ref. 17 ...

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