Faculty Collaboration Database

P2X receptor-stimulated calcium responses in preglomerular vascular smooth muscle cells involves 20-hydroxyeicosatetraenoic acid. J Pharmacol Exp Ther 2004 Dec;311(3):1211-7

Date

08/19/2004

Pubmed ID

15316085

DOI

10.1124/jpet.104.070797

Scopus ID

2-s2.0-10044255250 (requires institutional sign-in at Scopus site)   31 Citations

Abstract

The current study tested the hypothesis that endogenous 20-hydroxyeicosatetraenoic acid (20-HETE) contributes to the increase in intracellular calcium ([Ca2+]i) elicited by P2X receptor activation in renal microvascular smooth muscle cells. Vascular smooth muscle cells obtained from rats were loaded with fura-2 and studied using standard single cell fluorescence microscopy. Basal renal myocyte [Ca2+]i averaged 96 +/- 5 nM. ATP (10 and 100 microM) increased vascular smooth muscle cell [Ca2+]i by 340 +/- 88 and 555 +/- 80 nM, respectively. The cytochrome P450 hydroxylase inhibitor, N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS), or the 20-HETE antagonist, 20-hydroxyeicosa-6(Z),15(Z)-dienoic acid (20-HEDE), significantly attenuated the peak myocyte [Ca2+]i responses to 10 and 100 microM ATP. ATP (100 microM) increased vascular smooth muscle cell [Ca2+]i by 372 +/- 93 and 163 +/- 55 nM in the presence of DDMS or 20-HEDE, respectively. The P2X receptor agonist, alpha,beta-methylene-ATP (10 microM), increased myocyte [Ca2+]i by 78 +/- 12 nM, and this response was significantly attenuated by DDMS (40 +/- 15 nM). In contrast, the vascular smooth muscle cell [Ca2+]i evoked by the P2Y agonist, UTP (100 microM), was not altered by DDMS or 20-HEDE. The effect of 20-HETE on [Ca2+]i was also assessed, and the peak increases in [Ca2+]i averaged 62 +/- 12 and 146 +/- 70 nM at 20-HETE concentrations of 1 and 10 microM, respectively. These results demonstrate that 20-HETE plays a significant role in the renal microvascular smooth muscle cell [Ca2+]i response to P2X receptor activation.

Author List

Zhao X, Falck JR, Gopal VR, Inscho EW, Imig JD

MESH terms used to index this publication - Major topics in bold

Adenosine Triphosphate
Amides
Animals
Calcium
Capillaries
Cell Separation
Hydroxyeicosatetraenoic Acids
In Vitro Techniques
Kidney Glomerulus
Male
Muscle, Smooth, Vascular
Purinergic P2 Receptor Agonists
Rats
Rats, Sprague-Dawley
Receptors, Purinergic P2X
Renal Circulation
Spectrometry, Fluorescence
Sulfones