An ultrastructural and cytochemical analysis of the glabrous border of the bovine lip

Glabrous border of the lip of cattle had a malpighian epithelium 800 μm thick. The horny layer was about 200 μm thick and there was no granular layer visible with light microscopy or electron micrography. The more evident morphological features were: high concentration of tonofilaments, mitochondria in basal as well as in spinous cells; few small keratohyaline granules. Blood supply, as shown by the histochemical demonstration of TPPase, was composed of capillary loop which penetrated up to near the horny layer. The oxidative enzymes reactions of bovine lip epithelium were compared with those of rat lip epithelia. Microphotometric evaluation of histochemical preparations showed a greater activity of SDh and Gl-6-ph Dh in bovine glabrous border; LDh, on the contrary, revealed lower activity. Different structural and metabolic characteristics between epithelia of both species were noted.