The NK-1 receptor and a calcium-phospholipid pathway: inositol trisphosphate production and calcium movements induced by selective agonists of neurokinin receptors in rat parotid glands

• Published in: Journal of neurochemistry Vol. 58; no. 6; p. 2321
• Main Authors: Guillemain, I, Rollandy, I, Imhoff, V, Rossignol, B
• Format: Journal Article
• Language: English
• Published: England 01-06-1992
• Subjects: Animals; Calcium - metabolism; Calcium - physiology; Inositol 1,4,5-Trisphosphate - metabolism; Male; Parotid Gland - metabolism; Parotid Gland - physiology; Parotid Gland - ultrastructure; Peptide Fragments - pharmacology; Phospholipids - physiology; Rats; Rats, Inbred Strains; Receptors, Neurokinin-2; Receptors, Neurotransmitter - drug effects; Receptors, Neurotransmitter - physiology; Signal Transduction - physiology; Substance P - analogs & derivatives; Substance P - pharmacology
• ISSN: 0022-3042
• DOI: 10.1111/j.1471-4159.1992.tb10980.x

In the rat parotid gland, substance P has been shown to induce a phosphatidylinositol bisphosphate breakdown resulting in an inositol trisphosphate production. These data suggested that substance P activated a phospholipase C and thus mediated its effects through the calcium-phospholipid pathway. To determine which neurokinin (NK) receptor was involved in the substance P response, we have used selective agonists of the different NK receptors and examined their effects on both inositol trisphosphate production and calcium movements. A selective NK-1 receptor agonist, [Sar9Met(O2)11]-substance P, evoked an [3H]inositol trisphosphate production and a rapid and transient 45Ca2+ efflux. On the other hand, selective NK-2 and NK-3 receptor agonists, [beta-Ala8]-NKA(4-10) and [MePhe7]-NKB, respectively, were without effect. We conclude that, in the rat parotid glands, only the NK-1 receptors are coupled to the calcium-phospholipid pathway. The C-terminal part of substance P appeared to be sufficient to stimulate this route because the C-terminal octapeptide, substance P(4-11), mimicked substance P effects on both inositol trisphosphate production and calcium movements. The NK-2 and NK-3 receptors, if present in the rat parotid glands, are not associated with the calcium-phospholipid pathway.