ISSN:
1573-6881
Keywords:
Mg2+ efflux
;
heart mitochondria
;
respiration
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Physics
Notes:
Abstract Respiration-driven Mg2+ efflux from rat heart mitochondria has been studied in different conditions. Almost total release of Mg2+ from the mitochondria occurs upon addition of a proton/bivalent cation exchanger, A23187. The content of Mg2+ remaining in mitochondria after A23187 treatment is the same if part of the mitochondrial Mg2+ has already been extruded through the energy-linked mechanism. Some inhibition of Mg2+ efflux is observed in the presence of high concentrations of La3+ (100 µM). A proton/monovalent cation exchanger, nigericin, completely prevents Mg2+ efflux, whereas a cation conductor, valinomycin, considerably stimulates it. The results indicate that the main part of mitochondrial Mg2+ is present in a membrane-bounded compartment, probably in the matrix space. The driving force of the Mg2+ efflux appears to be the proton gradient (ΔpH) created by mitochondrial respiration.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00763835
Permalink
