The parakeratin layer of zinc-deficient rat buccal epithelial.

Weanling rats were fed a zinc-deificient diet, 1.3 ppm zinc, for four weeks. Parakeratotic changes of the buccal epithelium were studied by electron microscopy. The incomplete disintegration of the nucleus and cytoplasmic organelles in the horny layer is deemed to be due to insufficient function of zinc-related lytic enzymes.