LOCALIZATION AND ONSET OF AMYLASE ACTIVITY IN MOUSE SALIVARY GLANDS DETERMINED BY A SUBSTRATE FILM METHOD

Abstract

A starch substrate film technique was used to determine the localization and onset of amylase activity in the major salivary glands of mice. The earliest activity occurred in the parotid gland of males and females at 8 days of age. The intensity of the reaction rapidly increased so that by day 16 the entire parotid gland was amylase-positive. The submandibular gland exhibited the sexual dimorphism that has been characterized for the adult gland. Amylase activity was observed in the male at 24 days of age, shortly after the first morphologic differences between the submandibular glands of males and females became apparent. The female showed positive results at 36 days of age. Amylase activity in the submandibular glands was localized to the convoluted tubules. As the gland developed, the amylase activity increased in correlation with the increasing concentration of these tubules. The sublingual gland was always amylase-negative.