Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 50, Issue 1 M45-M48, Copyright © 1995 by The Gerontological Society of America
Extended stimulated parotid and submandibular secretion in a healthy young and old population
AJ Wu, BJ Baum and JA Ship
School of Dentistry, University of Michigan.
BACKGROUND. Previous morphological studies have shown that both the human
parotid and submandibular glands display age-related reductions in the
proportion of fluid secreting acinar cells. In contrast, short- term
functional studies of fluid secretion do not show such a consistent
disparity among different-aged persons. This study compared the ability of
a population of healthy young and old individuals to secret saliva from the
parotid and submandibular glands for an extended period of time under
conditions of intense gustatory stimulation. METHODS. Saliva was collected
over 30 minutes from 30 healthy, unmedicated individuals using 10% citric
acid as a gustatory stimulus. Of the 30 subjects, 15 were young (age range
27-40 years) and 15 were old (age range 60-97 years). Parotid salivary flow
rates were determined every minute, and submandibular flow rates were
determined at 2, 10, 20, and 30 minutes. A comparison was made between the
slopes of the two groups. The slopes were derived from the average salivary
flow rate at each time point. RESULTS. There was no difference in the
ability of the parotid glands of young and old individuals to secrete
saliva. In contrast, the submandibular glands of the elderly individuals
did not show the same pattern of secretion when compared to their younger
counterparts, who demonstrated increasing flow rates over the test period.
CONCLUSIONS. The parotid glands of young and old persons are able to
maintain high secretory ability under the stress of intense stimulation for
an extended period of time. Conversely, the submandibular gland
demonstrates an age-related, statistically significant difference in the
pattern of fluid secretion with an intense gustatory stimulus.
