Alpha 1-adrenergic responsiveness of young adult and aged rat submandibular cells in vitro.

The present study has evaluated, in vitro, alpha 1-adrenergic receptor mediated responses in submandibular cells from young adult and aged rats. Submandibular glands from different aged rats possess a similar number of alpha 1-adrenergic receptors that display comparable binding characteristics. Following alpha 1-adrenergic stimulation, cells from both groups of rats show a similar ability to mobilize intracellular Ca2+ (45Ca2+ time course, agonist dose-response) and to elicit a functional response (inhibition of protein synthesis by epinephrine) which reflects Ca2+ mobilization.