Plumb RD, El-Sherbeeny NA, Dixon LJ, Hughes SMT, Devine AB, Leahey WJ, McVeigh GE. NAD(P)H-dependent superoxide production in platelets: The role of angiotensin II and protein kinase C.
Clin Biochem 2005;
38:607-13. [PMID:
15922319 DOI:
10.1016/j.clinbiochem.2005.04.012]
[Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 04/01/2005] [Accepted: 04/12/2005] [Indexed: 11/19/2022]
Abstract
OBJECTIVES
Vascular NAD(P)H oxidase represents a major source for excessive superoxide production in hypertension. Angiotensin II (AngII) can activate NAD(P)H oxidase via the angiotensin II type 1 (AT1) receptor and protein kinase C (PKC). Platelets possess AT1 receptors and all the components of the NAD(P)H oxidase system. We employed this tissue model to explore mechanisms involved in AngII-mediated superoxide production.
DESIGN AND METHODS
Platelet suspensions from hypertensive patients' blood were activated with AngII or phorbol 12-myristate 13-acetate (PMA). Inhibitors of NAD(P)H oxidase, PKC, and the AT1 receptor were employed to study their effects on superoxide production.
RESULTS
Superoxide production was stimulated by AngII and PMA and attenuated by AT1 receptor antagonists (mean percentage reduction 80.2%, P<0.01) and inhibitors of PKC (mean reduction 94.8%, P<0.001) and NAD(P)H oxidase (mean reduction 100%, P< 0.001).
CONCLUSIONS
AngII stimulates platelet superoxide production through activation of vascular NAD(P)H oxidase via the AT1 receptor and PKC.
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