Journal of Dental Research, Vol 60, 1031-1038, Copyright © 1981 by International & American Associations for Dental Research Online Journals
Stimulatory and inhibitory effects of substance P on rat submandibular secretion
J. R. Martinez and A. M. Martinez
Intravenous infusions of the undecapeptide substance P caused a moderate
but transient secretory response from the rat submandibular gland. The
electrolyte composition of the saliva elicited by this peptide was
qualitatively similar to that of the secretion induced by
parasympathomimetic agents. Substance P inhibited the secretory response to
acetylcholine and isoproterenol, but did not modify the binding of specific
ligands to glandular autonomic receptors. It is concluded that this
naturally occurring peptide plays a role in the physiologic regulation of
salivary secretions, which involves both direct stimulatory effects and a
modulating action on the effect of autonomic neurotransmitters on the
salivary gland cells. The latter may involve similar effects of substance P
and the neurotransmitters on a metabolic pathway localized beyond receptor
activation.
