Effect of calcium on mitochondria from human term placenta.
We describe here the effects of free Ca2+ on several functions of mitochondria from human term placenta. In the presence of 0.1 microM free Ca2+, an inhibitory effect on both ADP-induced respiration and succinate-DCPIP reductase activity was observed. At the same Ca2+ concentration, ATPase activity as well as various segments of the respiratory chain were stimulated. However, a higher free Ca2+ concentration (0.3 microM) was needed to stimulate progesterone synthesis. Our results suggest that Ca2+ plays an important role in the metabolic functions of mitochondria from human term placenta.
Garduño
J P
JP
Departamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, D.F.
Espinosa-García
M T
MT
Pardo
J P
JP
Martínez
F
F
D000251:Adenosine Triphosphatases / Q000378:metabolism; D002118:Calcium / Q000494:pharmacology*; D004579:Electron Transport / Q000187:drug effects; D005260:Female; D006801:Humans; D008928:Mitochondria / Q000187:drug effects*; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D010920:Placenta / Q000187:drug effects* / Q000648:ultrastructure; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011374:Progesterone / Q000096:biosynthesis
D011374:Progesterone; D000226:Mitochondrial ADP, ATP Translocases; D000251:Adenosine Triphosphatases; D002118:Calcium