Influence of NH4Cl on polarized release of endogenous protein degradation products and on morphology in LLC-PK1 cells

Increased renal ammoniagenesis is thought to be a causative factor for rena l hypertrophy which occurs in several disorders accompanied by metabolic ac idosis, We studied the influence of ammonia on the polarized release of deg radation products of endogenous proteins in LLC-PK1 cells, Release of acid- soluble radioactivity to the extracellular space decreased under the influe nce of NH4Cl with a remarkable transient reduction of basolateral release, Electron microscopically NH4Cl-treated cells showed numerous enlarged lysos omes suggesting an accumulation of incompletely degraded cytoplasmatic mate rial in the lysosomal compartment, We conclude that split products of lysos omal degradation of endogenous proteins are preferentially transported to t he extracellular space via the basolateral plasma membrane, Copyright (C) 2 000 S. Karger AG, Basel.