title: Interaction of metallochromic indicators with calcium sequestering organelles.
abstract: Examples are presented of the interaction between cell organelles and metallochromic indicators used in the measurement of ionized Ca2+. Sarcoplasmic reticulum was found to sequester murexide type indicators along with Ca2+ in the presence of ATP, but not to sequester arsenazo III and antipyrylazo III. The presence of a permeable anion suppresses the sequestration of murexide type indicators by the sarcoplasmic reticulum. In the presence of ruthenium red, both rat liver and beef heart mitochondria release sequestered Ca2+ with arsenazo III, but not with murexide.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001152:Arsenicals / Q000494:pharmacology*; D001391:Azo Compounds / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D002118:Calcium / Q000378:metabolism*; D002417:Cattle; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D009114:Murexide / Q000494:pharmacology; D009282:Naphthalenesulfonates / Q000494:pharmacology; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism*
chemical_list: D001152:Arsenicals; D001391:Azo Compounds; D009282:Naphthalenesulfonates; D009114:Murexide; D000255:Adenosine Triphosphate; D002118:Calcium