Related Experiment Video
Updated: Sep 7, 2026

Retroductal Submandibular Gland Instillation and Localized Fractionated Irradiation in a Rat Model of Salivary Hypofunction
Published on: April 24, 2016
Stimulatory and inhibitory effects of substance P on rat submandibular secretion
Abstract:
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.
Related Concept Videos
Hormonal Regulation
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Regulation of Hormone Secretion
Humoral stimuli,...
Regulation of the Digestive System
The effectors in this regulation system are glands and smooth muscles. Activation of these...
Salivary Glands and Saliva
Intestinal Phase of Digestion
The arrival of the chyme in the small intestine distends the duodenum, which triggers the enterogastric reflex. This distension...

