Ca2+-uptake and -release phenomena from cardiac mitochondria under normal and ischemic conditions.
Guinea-pig and dog heart mitochondria were isolated in a KEA-medium. Ca2+-transport across mitochondrial membranes was measured continuously with an Aminco Dual-Wavelength-Spectrophotometer and murexide as a Ca2+-sensitive indicator. Ischemia was produced by cardioplegia at 15 degrees C according to Bretschneider. Guinea-pig heart mitochondria as well as mitochondria from dog heart show a spontaneous Ca2+-release without nonphysiological influence. Addition of 3.5 M Na+ can induce a very quick release of Ca2+ taken up by heart mitochondria. This release is different from that occurring spontaneously. Progressive ischemia results in a marked depression of Ca2+-uptake and spontaneous Ca2+-release.
D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D003331:Coronary Vessels; D004285:Dogs; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007511:Ischemia / Q000378:metabolism; D008297:Male; D008929:Mitochondria, Heart / Q000378:metabolism*; D012964:Sodium / Q000494:pharmacology
D012964:Sodium; D002118:Calcium