BayK 8644 increases resting calcium spark frequency in ferret ventricular myocytes

Hiroshi Satoh, Hideharu Hayashi, Lothar A. Blatter, Donald M Bers

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

BayK 8644, an L-type Ca2+ channel agonist, has been shown to increase sarcoplasmic reticulum (SR) Ca2+ release in dog and ferret ventricular muscle. The visualization of local increase in cytosolic Ca2+ concentration, called the 'Ca2+ spark', has enabled us to investigate the elementary events of the BayK-induced Ca2+ release from the SR. In this study, the effects of BayK on twitch Ca2+ transients and Ca2+ sparks were examined in ferret ventricular myocytes with laser scanning confocal microscopy and a fluorescent calcium indicator, fluo 3. BayK converted the post rest potentiation of twitch Ca2+ transients to decay. The Ca2+ spark frequency under control conditions was fairly constant during 20 s of rest after interruption of electrical stimulation. BayK (100 nM) increased the spark frequency by 465.7 ± 90.3% of control but did not change the spatial and temporal characteristics of the individual sparks. The increase in spark frequency by BayK was not affected by perfusion with Ca2+-free solution, but was suppressed by the addition of nifedipine (10 μM), suggesting that the BayK effects on Ca2+ sparks were mediated by the sarcolemmal dihydropyridine (DHP) receptor, but were independent of Ca2+ influx. These findings suggest that BayK activates SR Ca2+ release at rest through a putative linkage between the sarcolemmal DHP receptor and the SR ryanodine receptor.

Original languageEnglish (US)
Pages (from-to)58-61
Number of pages4
JournalHeart and Vessels
Volume12
Issue numberSUPPL. 12
StatePublished - 1997
Externally publishedYes

Fingerprint

Ferrets
Calcium Signaling
Sarcoplasmic Reticulum
Muscle Cells
L-Type Calcium Channels
Ryanodine Receptor Calcium Release Channel
Nifedipine
Confocal Microscopy
Electric Stimulation
Perfusion
Dogs
Calcium
Muscles

Keywords

  • BayK 8644
  • Calcium spark
  • Confocal microscopy
  • Fluo 3
  • Sarcoplasmic reticulum

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

Cite this

BayK 8644 increases resting calcium spark frequency in ferret ventricular myocytes. / Satoh, Hiroshi; Hayashi, Hideharu; Blatter, Lothar A.; Bers, Donald M.

In: Heart and Vessels, Vol. 12, No. SUPPL. 12, 1997, p. 58-61.

Research output: Contribution to journalArticle

Satoh, H, Hayashi, H, Blatter, LA & Bers, DM 1997, 'BayK 8644 increases resting calcium spark frequency in ferret ventricular myocytes', Heart and Vessels, vol. 12, no. SUPPL. 12, pp. 58-61.
Satoh, Hiroshi ; Hayashi, Hideharu ; Blatter, Lothar A. ; Bers, Donald M. / BayK 8644 increases resting calcium spark frequency in ferret ventricular myocytes. In: Heart and Vessels. 1997 ; Vol. 12, No. SUPPL. 12. pp. 58-61.
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