The role of the sodium pump and sodium-calcium exchange in recovery from calcium overload in guinea-pig ventricular myocytes.
A marked increase in [Ca2+]i is provoked in isolated guinea-pig ventricular myocytes by return to normal Tyrode solution after a period of exposure to fluid free of divalent cations. When the sarcolemma of the myocyte remains intact, [Ca2+]i falls back towards initial levels over the next 5 to 10 min in spite of the strong irreversible contracture. This recovery fails to occur if either the Na+ pump or Na(+)-Ca2+ exchange is inhibited once [Ca2+]i has risen.
British Heart Foundation Research Group, School of Veterinary Science, Bristol.
K K
KK
Minezaki
R A
RA
Chapman
D000818:Animals; D017920:Antiporters / Q000502:physiology*; D002118:Calcium / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005453:Fluorescence; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology; D008297:Male; D009206:Myocardium / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D012508:Sarcolemma / Q000378:metabolism / Q000502:physiology; D019831:Sodium-Calcium Exchanger; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology*; D013997:Time Factors
D017920:Antiporters; D019831:Sodium-Calcium Exchanger; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium