These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Importance of the presence of the N-terminal tripeptide of substance P for the stimulation of phosphatidylinositol metabolism in rat parotid gland: a possible activation of phospholipases C and D.
    Author: Rollandy I, Dreux C, Imhoff V, Rossignol B.
    Journal: Neuropeptides; 1989 Apr; 13(3):175-85. PubMed ID: 2469032.
    Abstract:
    In this study, we have compared the effects of Substance P (SP) and an SP deprived of the N-terminal tripeptide, SP(4-11), on phosphoinositide metabolism by measuring phosphoinositide breakdown, inositol phosphate production and inositol incorporation into phosphoinositides. This work shows that SP and SP(4-11) have similar effects on phosphatidylinositol-4.5 bisphosphate (PIP2) metabolism. In fact, SP(4-11), like SP, induces a rapid PIP2 breakdown. On the contrary, SP and SP(4-11) have different effects on phosphatidylinositol (PI) metabolism since SP induces a decrease of radioactivity in PI, whereas SP(4-11) does not. Both peptides stimulate [3H]-inositol mono-, bis- and trisphosphate (respectively IP1, IP2, IP3) production in a time and dose-dependent manner. The kinetic of IP3 production is directly correlated with the one of PIP2 breakdown. The time course of IP1 production after SP(4-11) shows a time delay, while the one after SP does not. Since SP evokes an IP1 production without any delay and a large decrease of radioactivity in PI (which cannot account for the small amount measured in IP1 accumulation) we suggest that SP could activate a PI specific phospholipase C (leading to a PI breakdown) and a phospholipase D. These activations would require the complete structure of SP while the classical PIP2 specific phospholipase C activation (which induces PIP2 breakdown) would only require the carboxamide part of the peptide. So the complete structure of SP would be necessary to have a complete response (stimulation of PIP2 and PI metabolism).
    [Abstract] [Full Text] [Related] [New Search]