Histochemically demonstrable changes in amylase activity in submaxillary salivary glands of puberal male mice following castration.

The sexual dimorphism in mouse submaxillary glands is well documented. The main difference is seen in the granular convoluted tubules (G.C.T.) which in the adult male are large and in the adult female are small and fewer. Previous studies have shown that amylase is localized histochemically to these G.C.T.'s; that following castration there is a histological reduction in size and number of the G.C.T.'s and a roughly 50 per cent decrease in amylase activity demonstrable biochemically. In the present study 74 male mice aged 60 days were divided in six groups. The animals were fasted overnight. Under general anaesthesia, the submaxillary glands on the left side were removed and frozen in liquid nitrogen for subsequent histochemistry. The animals were then castrated and returned to their cages. At periods of 2, 4, 6, 8, 10 and 12 weeks later, the other submaxillary gland was removed under the same conditions, and the animals were then killed. Fresh frozen cryostat sections of both glands were subjected to the starch substrate film technique for the histochemical demonstration of amylase. Adjacent sections were stained with HE. The 2-week animals showed a slight but define reduction in size and number of G.C.T.'s and a parallel reduction in amylase activity. This was more pronounced by 4 and 6 weeks. In the 4-week animals, however, the changes were not consistent, being more pronounced in some animals than in others. This same phenomenon was observed in the 6-, 8- and 10-week animals, in some of whom there was considerable G.C.T. atrophy in the submaxillaries and in others very much less. In many of the 12-week animals there was very little evidence of G.C.T. atrophy. These findings confirmed other studies which suggested that there may be some regeneration of G.C.T's, possibly as a result of influence of other endocrine glands such as thyroid, adrenal and pituitary.