The effect of lysosomotropic amines on beige mouse cells

The beige mutant in the mouse is characterized by enlarged lysosomes in many cell types due to increased fluidity of cellular membranes and organelle fusion. In this study, mutant fibroblasts derived from C57BL/ 6J;bgJ/bgJ animals were compared with control fibroblasts (C57BL/6J;+/+) for vacuolation when treated with lysosomotropic weak bases including ammonium chloride, trimethylamine, and methylamine. These amines produce vacuolation by their accumulation in cellular acidic compartments, which causes osmotic swelling and fusion of organelles due to the increase in pH. Beige cells exhibited greater vacuolation than control cells for all treatments, which was indicative of the mutant's effect on organelle fusion and membrane fluidity. Trimethylamine caused the most pronounced difference in vacuolation between mutant and control cells. This method allows for a simple morphological distinction between beige and control cells that also utilizes a physiological difference in the expression of the beige gene.