The effect of sarcoplasmic reticulum Ca2+ leak on contractile activity of guinea pig heart myocytes depends on activity of sarcoplasmic reticulum Ca2+-ATPase and Na+/Ca2+ exchanger

• Autorzy: Mackiewicz U. , Lewartowski B.
• Języki publikacji: EN

Abstrakty

EN

Decreased expression of sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA), overexpression of Na+/Ca2+ exchanger (NCX) and diastolic SR Ca2+ leak from the ryanodine receptors (RyRs) are believed to contribute to the decrease of myocyte contraction in failing heart. In this work we induced Ca2+ leak through RyRs in isolated myocytes of guinea pig hearts by 20µM FK-506. The SR Ca2+ leak resulted in (1) decreased amplitude of cell shortening and of Ca2+ transients, (2) decreased rate of Ca2+ transients decay (3) enhanced diastolic Ca2+ loss. The effect of FK-506 on amplitude of cell shortening was reversed and that on diastolic Ca2+ loss blocked by partial inhibition of NCX due to lowering Na+ concentration in superfusion solution from 144 mM to 100 mM. The amplitude of cell shortening and Ca2+ transients decreased by FK-506 was significantly increased by 10-7 M thapsigargin. In conclusion, the effect of SR Ca2+ leak induced by FK-506 on myocyte contraction is strictly dependent on activity of SERCA and NCX.

Słowa kluczowe

EN

guinea pig; sarcoplasmic reticulum; thapsigargin; myocyte; contractile activity; heart failure; heart; ryanodine receptor

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2008
• Tom: 59
• Numer: 2
• Opis fizyczny: p.287-300,fig.,ref.

Twórcy

autor

Mackiewicz U.

• Medical Centre of Postgraduate Education, Marymoncka St.99/101, 01-813 Warsaw, Poland

autor

Lewartowski B.