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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
Author(s) -
Guillemain Isabelle,
Rollandy Isabelle,
Imhoff Viviane,
Rossignol Bernard
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb10980.x
Subject(s) - endocrinology , neurokinin a , inositol , inositol trisphosphate , medicine , substance p , receptor , tachykinin receptor , calcium , inositol phosphate , phosphatidylinositol , agonist , chemistry , biology , biochemistry , neuropeptide , signal transduction
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, [Sar 9 Met(O 2 ) 11 ]‐substance P, evoked an [ 3 H]inositol trisphosphate production and a rapid and transient 45 Ca 2+ efflux. On the other hand, selective NK‐2 and NK‐3 receptor agonists, [β‐Ala 8 ]‐NKA(4‐10) and [MePhe 7 ]‐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‐l 1), 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.