Calcium accumulation by chondrocyte mitochondria.
Chick epiphyseal plate mitochondria observed in vitro suggest that energy dependent Ca++ uptake was maximal in the presence of ATP and a respiratory substrate. However, nucleotides other than ATP had no effect on this type of cation uptake. The observation that Ca++ accumulation was sensitive to the presence of 2,4-DNP and a number of respiratory inhibitors suggested that the mechanism of cation accumulation was similar to that described in tissues that do not undergo biological mineralization. Non-energy supported Ca++ acumulation was studied in the presence of rotenone and antimycin A. Under these conditions, the amount of Ca++ bound by skeletal tissue mitochondria was greater than bound by mitochondria obtained from noncalcifying tissues. Following isopycnic centrifugation, the Ca++ loaded mitochondria banded at different sucrose densties but the Ca++ affinity of mitochondria at each density band was similar. Hence, no particular mitochondrial species seems to be responsible for cation transport.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D002113:Calcification, Physiologic; D002118:Calcium / Q000378:metabolism*; D002356:Cartilage / Q000166:cytology*; D002645:Chickens; D003470:Culture Media; D003576:Electron Transport Complex IV / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D009924:Organ Culture Techniques; D011506:Proteins / Q000494:pharmacology; D013395:Sucrose / Q000494:pharmacology; D014475:Uncoupling Agents / Q000494:pharmacology
D003470:Culture Media; D011506:Proteins; D014475:Uncoupling Agents; D013395:Sucrose; D000255:Adenosine Triphosphate; D003576:Electron Transport Complex IV; D002118:Calcium