RESUMO
Using histological, morphometric and quantitative histoenzymological methods, the changes of lingual epithelium were studied in 40 outbred albino mice after 5 intraperitoneal injections of 100 micrograms of hydra peptide morphogen (HPM) per 1 kg of body weight. Administration of HPM was found to increase the total thickness of epithelial layer on the dorsal tongue surface in the interpapillary regions, while in the area of filiform papillae these changes were not significant. On the ventral tongue surface HPM induced a marked increase of total thickness of the epithelial layer as compared to that in control animals. Mitotic activity was increased in the epithelium covering the ventral surface and in the interpapillary regions on the dorsal tongue surface. Histoenzymologic study which involved the demonstration of NADH-diaphorase, succinate- and lactate-dehydrogenase (LDH) activities, followed by a cytophotometric evaluation of enzyme activity, has shown a stimulatory effect of HPM on the activity of all the enzymes studied, which was most pronounced in respect to LDH and was maximally expressed on the dorsal tongue surface. These findings collectively suggest that HPM exerts a stimulatory effect on proliferation activity and metabolism of lingual epithelium, which is differentially expressed in its variuoe topographical zones.