[Effects of mastication on the growth and development of salivary glands in male mice].
Mastication has attracted considerable attention in recent years for its effects on the postnatal growth and development of the mandible, brain, salivary glands and other organs in children. In this study, the relationship between mastication and growth and development of the salivary glands was examined, because the salivary glands are rich in growth factors and many kinds of biological polypeptides, and have endocrine and exocrine actions and effects, on the growth and metabolic rates in developing animals. The experiment utilized two groups of male mice, a control group fed a solid diet, and an experimental group receiving the paste diet ad lib. In the experimental group fed the paste diet, the increase of the tissue weights and the contents of DNA and RNA in the parotid and submandibular glands were lower than those of the control group. Also the rise of amylase activity in the parotid glands was depressed. Next, the polyamine metabolism in the parotid and submandibular glands was examined. The activities of the late limiting enzymes in polyamine syntheses, ornithine decarboxylase and S-adenosylmethionine decarboxylase and the lev- putrescine and spermidine in both parotid and submandibular glands were in the experimental group. These results suggest that mastication plays an important roles in the growth development of the parotid and submandibular glands in mice.
Kikuchi
K
K
Miki
M
M
Miyamoto
S
S
Arita
K
K
Nishino
M
M
D000818:Animals; D002455:Cell Division; D008297:Male; D008409:Mastication; D051379:Mice; D009929:Organ Size; D012469:Salivary Glands / Q000201:enzymology / Q000254:growth & development*