RT Journal Article
SR Electronic
T1 Similar Effects of Substance P and Related Peptides on Salivation and on Phosphatidylinositol Turnover in Rat Salivary Glands
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 78
OP 83
VO 18
IS 1
A1 MICHAEL R. HANLEY
A1 C. M. LEE
A1 LYNNE M. JONES
A1 ROBERT H. MICHELL
YR 1980
UL http://molpharm.aspetjournals.org/content/18/1/78.abstract
AB The effects of substance P and related peptides on salivation in vivo and on the incorporation of 3H-inositol into rat salivary gland lipids in vitro were compared. Physalaemin was the most active peptide tested on both responses. Substance P was less potent, but was three- to sixfold more potent than peptides consisting of the C-terminal 6-10 residues of substance P. Both the C-terminal pentapeptide and the C-terminal deamidated substance P showed a dramatic reduction of potency in both assays. Substance P receptors exist in all three rat salivary glands, and a stimulation of 3H-inositol incorporation was also observed in all three glands. The close correlation between the relative activities of the different substance P-related peptides in evoking salivation and 3H-inositol incorporation strongly indicates that the same population of substance P receptors is involved in each of these two responses and is consistent with the idea that phosphatidylinositol breakdown may be a reaction involved in stimulus-response coupling at the substance P receptors of salivary glands. The incorporation of 3H-inositol into parotid gland lipids could profitably be adopted as a simple and sensitive biochemical procedure for screening the biological activity of potential agonists and antagonists at substance P receptors.