Excitation-contraction coupling in ventricular myocytes: Effects of angiotensin II

W. H. Barry; H. Matsui; J. H.B. Bridge; K. W. Spitzer; J. Janicki; B. O'Rourke; G. Kessler-Icekson; M. Morad

doi:10.1007/978-1-4615-1893-8_4

Excitation-contraction coupling in ventricular myocytes: Effects of angiotensin II

W. H. Barry, H. Matsui, J. H.B. Bridge, K. W. Spitzer, J. Janicki, B. O'Rourke, G. Kessler-Icekson, M. Morad

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Abstract

The effects of the vasoactive peptide angiotensin II (AII) on contractility and excitation-contraction coupling in isolated adult rabbit ventricular myocytes were investigated. In most ventricular myocytes, AII (10^-8 M) induced a significant increase in fractional shortening which was not associated with an increase in the calcium transient measured with indo- 1. AII did increase the intracellular pH by approximately 0.2 5 pH units coincident with the positive inotropic effect. Effects of AII on pH and contractility were blocked by inhibitors of Na⁺/H⁺ exchange. AII also increased the rate of pHi recovery from intracellular acidosis at pH(i) values above 6.9. AII was shown not to affect the L-type inward calcium current. However, in an occasional cell, AII was observed to cause a slight increase in the calcium transient. We hypothesize that this response may reflect an increase of calcium influx on the sodium calcium exchanger, as a consequence of an increase in subsarcolemmal sodium concentration resulting from enhanced Na⁺-H⁺ exchange.

Original language	English (US)
Pages (from-to)	31-39
Number of pages	9
Journal	Advances in experimental medicine and biology
Volume	382
DOIs	https://doi.org/10.1007/978-1-4615-1893-8_4
State	Published - 1995
Externally published	Yes

ASJC Scopus subject areas

General Biochemistry, Genetics and Molecular Biology

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title = "Excitation-contraction coupling in ventricular myocytes: Effects of angiotensin II",

abstract = "The effects of the vasoactive peptide angiotensin II (AII) on contractility and excitation-contraction coupling in isolated adult rabbit ventricular myocytes were investigated. In most ventricular myocytes, AII (10-8 M) induced a significant increase in fractional shortening which was not associated with an increase in the calcium transient measured with indo- 1. AII did increase the intracellular pH by approximately 0.2 5 pH units coincident with the positive inotropic effect. Effects of AII on pH and contractility were blocked by inhibitors of Na+/H+ exchange. AII also increased the rate of pHi recovery from intracellular acidosis at pH(i) values above 6.9. AII was shown not to affect the L-type inward calcium current. However, in an occasional cell, AII was observed to cause a slight increase in the calcium transient. We hypothesize that this response may reflect an increase of calcium influx on the sodium calcium exchanger, as a consequence of an increase in subsarcolemmal sodium concentration resulting from enhanced Na+-H+ exchange.",

author = "Barry, {W. H.} and H. Matsui and Bridge, {J. H.B.} and Spitzer, {K. W.} and J. Janicki and B. O'Rourke and G. Kessler-Icekson and M. Morad",

year = "1995",

doi = "10.1007/978-1-4615-1893-8_4",

language = "English (US)",

volume = "382",

pages = "31--39",

journal = "Advances in experimental medicine and biology",

issn = "0065-2598",

publisher = "Springer New York",

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TY - JOUR

T1 - Excitation-contraction coupling in ventricular myocytes

T2 - Effects of angiotensin II

AU - Barry, W. H.

AU - Matsui, H.

AU - Bridge, J. H.B.

AU - Spitzer, K. W.

AU - Janicki, J.

AU - O'Rourke, B.

AU - Kessler-Icekson, G.

AU - Morad, M.

PY - 1995

Y1 - 1995

N2 - The effects of the vasoactive peptide angiotensin II (AII) on contractility and excitation-contraction coupling in isolated adult rabbit ventricular myocytes were investigated. In most ventricular myocytes, AII (10-8 M) induced a significant increase in fractional shortening which was not associated with an increase in the calcium transient measured with indo- 1. AII did increase the intracellular pH by approximately 0.2 5 pH units coincident with the positive inotropic effect. Effects of AII on pH and contractility were blocked by inhibitors of Na+/H+ exchange. AII also increased the rate of pHi recovery from intracellular acidosis at pH(i) values above 6.9. AII was shown not to affect the L-type inward calcium current. However, in an occasional cell, AII was observed to cause a slight increase in the calcium transient. We hypothesize that this response may reflect an increase of calcium influx on the sodium calcium exchanger, as a consequence of an increase in subsarcolemmal sodium concentration resulting from enhanced Na+-H+ exchange.

AB - The effects of the vasoactive peptide angiotensin II (AII) on contractility and excitation-contraction coupling in isolated adult rabbit ventricular myocytes were investigated. In most ventricular myocytes, AII (10-8 M) induced a significant increase in fractional shortening which was not associated with an increase in the calcium transient measured with indo- 1. AII did increase the intracellular pH by approximately 0.2 5 pH units coincident with the positive inotropic effect. Effects of AII on pH and contractility were blocked by inhibitors of Na+/H+ exchange. AII also increased the rate of pHi recovery from intracellular acidosis at pH(i) values above 6.9. AII was shown not to affect the L-type inward calcium current. However, in an occasional cell, AII was observed to cause a slight increase in the calcium transient. We hypothesize that this response may reflect an increase of calcium influx on the sodium calcium exchanger, as a consequence of an increase in subsarcolemmal sodium concentration resulting from enhanced Na+-H+ exchange.

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U2 - 10.1007/978-1-4615-1893-8_4

DO - 10.1007/978-1-4615-1893-8_4

M3 - Article

C2 - 8540409

AN - SCOPUS:0029089474

SN - 0065-2598

VL - 382

SP - 31

EP - 39

JO - Advances in experimental medicine and biology

JF - Advances in experimental medicine and biology

ER -

Excitation-contraction coupling in ventricular myocytes: Effects of angiotensin II

Abstract

ASJC Scopus subject areas

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