Cortisol inhibition of development of various lysosomal enzymes in cultured palatal shelves from mouse embryos.

The lysosomal enzymes, non-specific esterases, beta-glucuronidase, N-acetyl-beta-glucosaminidase and aryl sulphatases A and B, were examined histochemically in medial-edge epithelia (MEE) of single palatal shelves in vitro. Activities of most enzymes increased gradually in MEE with a peak at 24-26 h of culture. Aryl sulphatase B activities were lower than the others and aryl sulphatase A activities could not be detected in the palatal cells during the entire culture period. By 48 h, MEE cells degenerated and were lost. Cortisol suppressed increased activities of these hydrolytic enzymes and prevented programmed breakdown of the palatal epithelium.