In:
American Journal of Physiology-Renal Physiology, American Physiological Society, Vol. 292, No. 5 ( 2007-05), p. F1380-F1389
Abstract:
Experiments were performed to establish the pharmacological profile of purinoceptors and to identify the signal transduction pathways responsible for increases in intracellular calcium concentration ([Ca 2+ ] i ) for cultured mouse mesangial cells. Mouse mesangial cells were loaded with fura 2 and examined using fluorescent spectrophotometry. Basal [Ca 2+ ] i averaged 102 ± 2 nM ( n = 346). One hundred micromolar concentrations of ATP, ADP, 2′,3′-(benzoyl-4-benzoyl)-ATP (BzATP), ATP-γ-S, and UTP in normal Ca 2+ medium evoked peak increases in [Ca 2+ ] i of 866 ± 111, 236 ± 18, 316 ± 26, 427 ± 37, and 808 ± 73 nM, respectively. UDP or 2-methylthio-ATP (2MeSATP) failed to elicit significant increases in [Ca 2+ ] i , whereas identical concentrations of adenosine, AMP, and α,β-methylene ATP (α,β-MeATP) had no detectable effect on [Ca 2+ ] i . Removal of Ca 2+ from the extracellular medium had no significant effect on the peak increase in [Ca 2+ ] i induced by ATP, ADP, BzATP, ATP-γ-S, or UTP compared with normal Ca 2+ ; however, Ca 2+ -free conditions did accelerate the rate of decline in [Ca 2+ ] i in cells treated with ATP and UTP. [Ca 2+ ] i was unaffected by membrane depolarization with 143 mM KCl. Western blot analysis for P2 receptors revealed expression of P2X 2 , P2X 4 , P2X 7 , P2Y 2 , and P2Y 4 receptors. No evidence of P2X 1 and P2X 3 receptor expression was detected, whereas RT-PCR analysis reveals mRNA expression for P2X 1 , P2X 2 , P2X 3 , P2X 4 , P2X 7 , P2Y 2 , and P2Y 4 receptors. These data indicate that receptor-specific P2 receptor activation increases [Ca 2+ ] i by stimulating calcium influx from the extracellular medium and through mobilization of Ca 2+ from intracellular stores in cultured mouse mesangial cells.
Type of Medium:
Online Resource
ISSN:
1931-857X
,
1522-1466
DOI:
10.1152/ajprenal.00349.2006
Language:
English
Publisher:
American Physiological Society
Publication Date:
2007
detail.hit.zdb_id:
1477287-5
