Histochemical Studies of Alkaline Phosphatase on the Lingual Mucosa

Abstract

A strong alkaline phosphatase reaction was found in all cell nuclei in the papillae of the connective tissue corresponding to each lingual papilla of mice. It was also established that the strong activity is first shown on the 19th embryonic day, when formation of the lingual papillae is completed and cornification of the superficial epithelium on the dorsal surface of the tongue begins. Subsequently this remains the same throughout life.On the other hand no alkaline phosphatase activity was demonstrated in the papillae of other parts such as the lip, the palatine rugae or the genital eminence. In contrast to this finding may be cited the fact that according to JOHNSON et al the papillae at the bottom of the follicle of the developing hair show a strong activity. With these points in mind it seems permissible to hypothesize that a strong alkaline phosphatase activity in the lingual papillae is associated with some structural peculiarity of these regions, such as strong cornification.As for the reactions of the lingual papillae in other species of mammals, the same picture was seen in dogs, rats and rabbits as in mice, but those in men, horses, cattle, cats, guinea pigs and hamsters were found to be negative.