Effect of prostacyclin on platelet intracellular free calcium concentration of hypertensive and normotensive humans

Hiroaki Komura, Richard D. Bukoski, Njeri Karanja, Cynthia Morris, Tetsuji Shingu, David A. McCarron

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Platelet intracellular free calcium concentration ([Ca2+]i) has been reported to be increased in essential hypertensive patients (EHT) as compared with normotensive controls (NT). Prostacyclin (PGI2), which influences cellular Ca2+, has been reported to be reduced in EHT. This study tested the hypothesis that the resting level of platelet [Ca2+]i, in humans is influenced by PGI2. We also investigated the role of PGI2 in regulating platelet [Ca2+]i, of 28 EHT subjects compared to 28 NT controls. Platelet [Ca2+]i, was measured using the fluorescent Ca2+ probe fura-2 under control conditions and a 10-min preincubation with PGI2. Simultaneous measurement of platelet cyclic-adenosine 3′:5′-monophosphate (cAMP) was performed by radioimmunoassay. The resting level of platelet [Ca2+]i, was significantly higher in EHT than in NT (32.7 ± 1.4 ν 28.3 ± 0.9 nmol/L; P <.01). PGI2 from 30 nM to 1 μmol/L lowered the resting level of platelet [Ca2+]i, in a dose-dependent manner (EHT -22.2 ± 2.4, NT -22.9 ± 2.3%, 1 μmol/L PGI2); however, no significant difference in platelet [Ca2+]i was observed between NT and EHT. While prostacyclin induced a transient rise in platelet cAMP, the magnitude of PGI2-induced cAMP level was similar between the two groups. These results do not support the hypothesis that endogenous PGI2 activity contributes to the increased level of platelet [Ca2+]i in EHT, although PGI2 incubation lowered the resting level of platelet [Ca2+]i.

Original languageEnglish (US)
Pages (from-to)730-735
Number of pages6
JournalAmerican Journal of Hypertension
Volume6
Issue number9
StatePublished - Sep 1993

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Epoprostenol
Blood Platelets
Calcium
Adenosine
Fura-2
Fluorescent Dyes
Radioimmunoassay

Keywords

  • calcium
  • cAMP
  • essential hypertension
  • platelet
  • Prostacyclin

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

Effect of prostacyclin on platelet intracellular free calcium concentration of hypertensive and normotensive humans. / Komura, Hiroaki; Bukoski, Richard D.; Karanja, Njeri; Morris, Cynthia; Shingu, Tetsuji; McCarron, David A.

In: American Journal of Hypertension, Vol. 6, No. 9, 09.1993, p. 730-735.

Research output: Contribution to journalArticle

Komura, Hiroaki ; Bukoski, Richard D. ; Karanja, Njeri ; Morris, Cynthia ; Shingu, Tetsuji ; McCarron, David A. / Effect of prostacyclin on platelet intracellular free calcium concentration of hypertensive and normotensive humans. In: American Journal of Hypertension. 1993 ; Vol. 6, No. 9. pp. 730-735.
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