Reduction by cycloheximide of lysosomal proteolytic enzyme activity and rate of protein degradation in organ-cultured hearts.

Cycloheximide, an agent whose primary action is inhibition of protein synthesis, also causes a decrease in the rate of protein degradation in cultured fetal mouse hearts. This is associated with marked decreases in the activities of cathespin D and other lysosomal hydrolases. It is suggested that reduced lysosomal proteolytic capacity may contribute to cycloheximide-induced inhibition of protein degradation.