Changes in p2y1 nucleotide receptor activity during the development
of rat salivary glands.
Park, Minjung K., Richard C. Garrad, Gary A. Weisman, and John T.
Turner.
Departments of Pharmacology and Biochemistry, School of Medicine,
University of Missouri-Columbia, Columbia, Missouri, 65212
APStracts 3:0401C, 1996.
Experiments using dispersed salivary gland cells from 1 day-old rats
indicated the presence of the P2Y nucleotide receptor subtype, P2Y1,
based on the agonist potency profile for mobilization of
intracellular free calcium (2-methylthio
-ATP>ADP>ADP[beta]S>ATP with UTP ineffective) and
sequence analysis of RT-PCR products obtained with P2Y1 receptor
-specific primers. P2Y1 receptor activity appears to be
developmentally regulated in that calcium mobilization in response to
the P2Y1-selective agonist, 2-methylthio-ATP, decreased as animal age
increased, with the maximal response of 129 +/- 23 nM, obtained in 1
day-old animals, decreasing to 30 +/- 3 nM in 4 week-old animals.
However, the abundance of P2Y1 receptor mRNA, assessed by semi
-quantitative RT-PCR, did not change over this time period, suggesting
that receptor activity is regulated by some mechanism other than
changes in steady-state levels of P2Y1 receptor mRNA. These findings
indicate that functional P2Y1 nucleotide receptors are expressed in
immature salivary glands and that receptor activity decreases as the
glands mature, suggesting that P2Y1 receptors may have an important
role during salivary gland development.
Received 12 August 1996; accepted in final form 21 November 1996.
APS Manuscript Number C459-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996