Transport interaction phenomena between monoquaternary and polymethylene-bisquaternary amines in mouse kidney cortex...

The polymethylene-bisquaternary amine 14C-decamethonium accumulates in mouse kidney cortex slices incubated in Krebs-Ringer bicarbonate buffer (37 degrees C, pH 7.4) aerated with O2-CO2 95:5 v/v%. The accumulation rate was enhanced in the presence of monoquaternary amines which on the other hand depressed maximum accumulation ratio of decamethonium in the tissue. The stimulation phenomenon was apparently related to the intracellular concentration of monoquaternary amine since tissue preloaded with a monoquaternary amine took up decamethonium at an increased rate. This effect was due to an accelerated influx of decamethonium and not to inhibition of efflux since no decamethonium efflux was shown to occur in wash-out experiments. Flux stimulation may represent an interaction phenomenon of accelerative exchange diffusion type. Furthermore, various amines inhibited accumulation of decamethonium in a competitive manner. The study supports the idea that common steps are involved in cellular transport of monoquaternary and polymethylene-bisquaternary amines in the kidney.