Open AccessRegulation of Ca 2+ Efflux from Kidney and Liver Mitochondria by Unsaturated Fatty Acids and Na + Ions
Author(s) -
ROMAN Izabela,
GMAJ Piotr,
NOWICKA Cecylia,
ANGIELSKI Stefan
Publication year - 1979
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1979.tb04279.x
Subject(s) - efflux , mitochondrion , ruthenium red , chemistry , biochemistry , phospholipase a2 , phospholipase , albumin , fatty acid , calcium , organic chemistry , enzyme
The effects of fatty acids and monovalent cations on the Ca 2+ efflux from isolated liver and kidney mitochondria were investigated by means of electrode techniques. It was shown that unsaturated fatty acids and saturated fatty acids of medium chain length (C 12 and C 14 ) induced a Ca 2+ efflux from mitochondria which was not inhibited by ruthenium red, but was specifically inhibited by Na + and Li + . The Ca 2+ ‐releasing activity of unsaturated fatty acids did not correlate with their uncoupling activity. In kidney mitochondria a spontaneous, temperature‐dependent Ca 2 efflux was observed which was inhibited either by albumin or by Na + . It is suggested that the net Ca 2+ accumulation by mitochondria depends on the operation of independent pump and leak pathways. The pump is driven by the membrane potential and can be inhibited by ruthenium red, the leak depends on the presence of unsaturated fatty acids and is inhibited by Na + and Li + . It is suggested that the unsaturated fatty acids produced by mitochondrial phospholipase A 2 can be essential in the regulation of the Ca 2+ retention in and the Ca 2+ release from the mitochondria.