Histochemistry of the keratohyalin granules in human oral leukoplakia

Abstract

The keratohyalin granules from 25 human oral leukoplakias, showing benign hyperorthokeratosis histologically, were examined employing a series of histochemical techniques. The tissues were fixed in 10% neutral buffered formalin, 80% methanol, or Carnoy's fluid. The keratohyalin granules stained intensely with Pauly's reagent, Congo red and Harris hematoxylin, indicating the presence of proteins. This was confirmed by abolishing the staining reaction by pretreatment with proteolytic enzymes. The keratohyalin granules also reacted with methyl green‐pyronin by staining pink at their peripheries; this staining was abolished by pretreatment with ribonuclease, indicating the presence of ribo‐nucleotides. The keratohyalin granules partially stained with toluidine blue and colloidal iron, indicating the presence of acidic polysaccharides. The keratohyalin granules did not react with the Feulgen reagent, suggesting the absence of DNA. Our studies indicate that the keratohyalin granules in human oral leukoplakia are primarily protein(s) complexed with polyribonucleotides. The presence of a carbohydrate moiety suggests the possibility of a protein‐polysaccharide component in the granules.

Histological and ultrastructural observations of eosinophilic keratohyalin granules in filiform papillae of pig tongue

“…In contrast, however, the typically described keratohyalin granules stain intensely with Harris' hematoxylin [Ugel, 1971 ;Singh et al, 1975] thus impart ing a basophilic appearance. On the other hand, analysis of correlative data from vari ous laboratories employing histochemical, autoradiographic, ultrastructural and biochemical methods have indicated that the basophilic keratohyalin granules from epithelium of oral mucosa and skin are ultrastructurally heterogeneous and also vary in their biological composition [Farbman, 1966a;Sibrack et al, 1974;Matoltsy et al, 1974;Fukuyama and Epstein, 1975;Singh et al, 1976].…”

Recent advances in oral mucosal research

“…Similar keratohyalin granules are found in masticatory mucosae but, additionally, in both masticatory and lining mucosae, there are keratohyalin granules of spherical shape in association with ribosomes but not, apparently, with tonofilaments; within any particular cell, one type of granule tends to prevail (Jessen 1970, Schroeder 1981. Regional variation in the composition of oral keartohyalin has also been demonstrated by histochemical methods (Singh et al 1975(Singh et al , 1980.…”