Reduced capacity of Ca²+ retention in liver as compared to kidney mitochondria. ADP requirement.
Ca²+ loading in mitochondria promotes the opening of a non-selective transmembrane pathway. Permeability transition is also associated with the interaction of cyclophilin D at the internal surface of the non-specific transmembrane pore. This interaction is circumvented by cyclosporin A and ADP. Our results show that, in the absence of ADP, liver mitochondria were unable to retain Ca²+, they underwent a fast and large amplitude swelling, as well as a rapid collapse of the transmembrane potential. In contrast, in the absence of ADP, kidney mitochondria retained Ca²+, swelling did not occur, and the collapse of the membrane potential was delayed. Ca²+ efflux was reversed by the addition of ADP and cyclosporin A. Our findings indicate that the differences between liver and kidney mitochondria are due to the low association of cyclophilin D to the ADP/ATP carrier found in kidney mitochondria as compared to liver mitochondria.
Zazueta
Cecilia
C
Departamento de Bioquímica Instituto Nacional de Cardiología, Ignacio Chávez, Juan Badiano # 1, Tlalpan, México DF014080, México.
García
Noemí
N
Martínez-Abundis
Eduardo
E
Pavón
Natalia
N
Hernández-Esquivel
Luz
L
Chávez
Edmundo
E
D000244:Adenosine Diphosphate / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D000081406:Peptidyl-Prolyl Isomerase F; D021983:Cyclophilins / Q000378:metabolism; D016572:Cyclosporine / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D053078:Membrane Potential, Mitochondrial / Q000502:physiology; D008928:Mitochondria / Q000378:metabolism*; D051381:Rats; D013053:Spectrophotometry
D000081406:Peptidyl-Prolyl Isomerase F; D000244:Adenosine Diphosphate; D016572:Cyclosporine; D021983:Cyclophilins; D002118:Calcium