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Extracellular ATP in the regulation of renal microvascular function 1
Author(s) -
Inscho Edward W.,
Mitchell Kenneth D.,
Navar L. Gabriel
Publication year - 1994
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.8.3.8143938
Subject(s) - afferent arterioles , tubuloglomerular feedback , adenosine , vasoconstriction , medicine , endocrinology , macula densa , chemistry , arteriole , extracellular , purinergic receptor , kidney , biology , microcirculation , angiotensin ii , biochemistry , receptor , renin–angiotensin system , blood pressure
Considerable attention has been focused on the purine nucleoside, adenosine, in the control of renal blood flow, epithelial transport, and renin secretion; however, surprisingly little attention has been directed toward the renal effects of purine nucleotides such as adenosine triphosphate (ATP). Recent studies utilizing in vivo micropuncture and in vitro techniques have demonstrated that renal vascular, epithelial, and mesangial cells respond to extracellular ATP via mechanisms distinct from those elicited by adenosine. ATP vasoconstricts afferent but not efferent arterioles whereas adenosine vasoconstricts both vascular segments. Adenosine‐mediated afferent arteriolar vasoconstriction is abolished by adenosine receptor antagonists, whereas the response to ATP is enhanced. ATP‐mediated vasoconstriction reaches a maximum within seconds of exposure while the vasoconstriction induced by adenosine develops more slowly. L‐type calcium channel antagonists such as diltiazem or felodipine prevent the sustained afferent vasoconstriction produced by ATP. Data from micropuncture experiments indicate that peritubular capillary infusion of ATP reduces glomerular pressure and results in marked attenuation of the tubuloglomerular feedback mechanism, which transmits signals from the macula densa to the afferent arteriole. These data support the existence of ATP‐sensitive P 2 purinoceptors in the preglomerular microvasculature that contribute to the control of renal vascular function via activation of calcium channels.—Inscho, E. W., Mitchell, K. D., Navar, L. G. Extracellular ATP in the regulation of renal microvascular function. FASEB J. 8: 319‐328; 1994.