Journal
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
Volume 282, Issue 2, Pages C289-C301Publisher
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpcell.01387.2000
Keywords
purinergic receptors; cytosolic calcium; ectoadenosine-triphosphatases; exocytosis; nitric oxide
Categories
Ask authors/readers for more resources
ATP and its metabolites regulate vascular tone; however, the sources of the ATP released in vascular beds are ill defined. As such, we tested the hypothesis that all limbs of an extracellular purinergic signaling system are present in vascular endothelial cells: ATP release, ATP receptors, and ATP receptor-triggered signal transduction. Primary cultures of human endothelial cells derived from multiple blood vessels were grown as monolayers and studied using a bioluminescence detection assay for ATP released into the medium. ATP is released constitutively and exclusively across the apical membrane under basal conditions. Hypotonic challenge or the calcium agonists ionomycin and thapsigargin stimulate ATP release in a reversible and regulated manner. To assess expression of P2X purinergic receptor channel subtypes (P2XRs), we performed degenerate RT-PCR, sequencing of the degenerate P2XR product, and immunoblotting with P2XR subtype-specific antibodies. Results revealed that P2X(4) and P2X(5) are expressed abundantly by endothelial cell primary cultures derived from multiple blood vessels. Together, these results suggest that components of an autocrine purinergic signaling loop exist in the endothelial cell microvasculature that may allow for self-regulation of endothelial cell function and modulation of vascular tone.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available