RT Journal Article
SR Electronic
T1 3h-substance P binding to salivary gland membranes. Regulation by guanyl nucleotides and divalent cations.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 563
OP 569
VO 23
IS 3
A1 Lee, C M
A1 Javitch, J A
A1 Snyder, S H
YR 1983
UL http://molpharm.aspetjournals.org/content/23/3/563.abstract
AB With appropriate measures to protect 3H-substance P (3H-SP) from proteolytic degradation and from nonspecific adsorption to glass-fiber filters, we have been able to demonstrate reliably a high-affinity specific binding of 3H-SP to rat submaxillary/sublingual gland membranes with a KD of 1 nM and Bmax of 6 pmoles/g of tissue. The relative potencies of various SP fragments and related analogues in reducing 3H-SP binding parallel their potencies in stimulating phosphatidylinositol turnover, amylase release, and salivation, thus supporting an association of the observed 3H-SP binding site with the physiological SP receptors in this tissue. This binding is selectively stimulated by some divalent cations (Mn2+ greater than Mg2+ greater than Ca2+) but inhibited by several guanyl nucleotides, suggesting a possible linkage to adenylate cyclase. However, no effect of SP on either the basal or the norepinephrine-stimulated adenylate cyclase activity could be demonstrated in salivary gland homogenates.