Journal of Dental Research, Vol 68, 1247-1251, Copyright © 1989 by International & American Associations for Dental Research Online Journals
Effects of thyroxine and dexamethasone on rat submandibular glands
G. B. Sagulin and G. M. Roomans
Department of Prosthodontics, Karolinska Institutet, Huddinge, Sweden.
Glucocorticoids and thyroxine are known to have a marked effect on the flow
rate and protein composition of rat parotid saliva in hormonally intact
animals. In the present study, the effects of a one-week treatment of male
rats with dexamethasone and thyroxine were studied by electron microscopy
and x-ray micro-analysis, and by measurement of the flow rate and
determination of the chemical composition of pilocarpine-induced
submandibular saliva. Thyroxine had the most extensive effects on the
submandibular gland. The acinar cells were enlarged and filled with mucus;
the cellular calcium concentration was significantly increased. The flow
rate of the submandibular saliva was significantly reduced compared with
that in saline-injected control animals. Thyroxine caused an increase in
the concentrations of protein, total calcium, and potassium in the saliva.
Dexamethasone had no significant effects on gland ultrastructure or on the
elemental composition of the acinar cells; flow rate was not affected, but
the concentrations of protein, calcium, and potassium were significantly
increased. The effects of dexamethasone and thyroxine on the flow rate and
protein composition of pilocarpine-induced rat submandibular saliva differ
from those reported earlier for rat parotid saliva after simultaneous
stimulation with pilocarpine and isoproterenol.
