Biomaterial Database

Age-related changes in respiration coupled to phosphorylation. II. Cardiac mitochondria. 1988

J H Kim, and E Shrago, and C E Elson

Departments of Nutritional Sciences, University of Wisconsin, Madison 53706.

Age-related changes in mitochondrial adenine nucleotide metabolism may underlie the progressive decline in cardiac function. Oxidase activity coupled with phosphorylation, adenine nucleotide translocase (AdNT) activity, adenine nucleotide pool size and membrane lipid composition were determined using cardiac mitochondria from young (3 months), mature (12 months) and aged (24 months) Fischer 344 male rats which had been fed NIH-31 diet. While an age-associated 15% decrease in respiratory activity was not significant, AdNT activity of the aged rat was 20% lower (P less than 0.05) than that of the young rat. The exchangeable matrix adenine nucleotide pool (ATP + ADP) tended to decrease with age. In comparison to the young, membrane lipids of cardiac mitochondria from aged rat had a 43% higher (P less than 0.01) cholesterol/phospholipid-Pi ratio and a significantly lower (P less than 0.01) phosphatidyl ethanolamine/phosphatidyl choline ratio. The overall change in the fatty acid pattern of mitochondrial membrane lipids resulted in a significant (P less than 0.01) decrease in the n-6/n-3 fatty acid ratio. All values obtained for the mature rat fell between those of the young and aged rats. These data suggest that the reduced cardiac AdNT activity in the aged rat is a consequence of both a diminished pool of exchangeable adenine nucleotides and a lower AdNT velocity. Age-related changes in the lipid components of the membrane matrix in which the AdNT is embedded may underlie the decrease in respiratory activity.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D008563	Membrane Lipids	Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.	Cell Membrane Lipid,Cell Membrane Lipids,Membrane Lipid,Lipid, Cell Membrane,Lipid, Membrane,Lipids, Cell Membrane,Lipids, Membrane,Membrane Lipid, Cell,Membrane Lipids, Cell
D008929	Mitochondria, Heart	The mitochondria of the myocardium.	Heart Mitochondria,Myocardial Mitochondria,Mitochondrion, Heart,Heart Mitochondrion,Mitochondria, Myocardial
D009713	Nucleotidyltransferases	A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.	Nucleotidyltransferase
D010085	Oxidative Phosphorylation	Electron transfer through the cytochrome system liberating free energy which is transformed into high-energy phosphate bonds.	Phosphorylation, Oxidative,Oxidative Phosphorylations,Phosphorylations, Oxidative
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D000226	Mitochondrial ADP, ATP Translocases	A class of nucleotide translocases found abundantly in mitochondria that function as integral components of the inner mitochondrial membrane. They facilitate the exchange of ADP and ATP between the cytosol and the mitochondria, thereby linking the subcellular compartments of ATP production to those of ATP utilization.	ADP,ATP Carrier,ADP,ATP Translocator Protein,Adenine Nucleotide Translocase,ADP Translocase,ATP Translocase,ATP,ADP-Carrier,ATP-ADP Translocase,Adenine Nucleotide Carrier (Mitochondrial),Mitochondrial ADP-ATP Carriers,ADP-ATP Carriers, Mitochondrial,Mitochondrial ADP ATP Carriers
D000227	Adenine Nucleotides		Adenine Nucleotide,Adenosine Phosphate,Adenosine Phosphates,Nucleotide, Adenine,Nucleotides, Adenine,Phosphate, Adenosine,Phosphates, Adenosine
D000244	Adenosine Diphosphate	Adenosine 5'-(trihydrogen diphosphate). An adenine nucleotide containing two phosphate groups esterified to the sugar moiety at the 5'-position.	ADP,Adenosine Pyrophosphate,Magnesium ADP,MgADP,Adenosine 5'-Pyrophosphate,5'-Pyrophosphate, Adenosine,ADP, Magnesium,Adenosine 5' Pyrophosphate,Diphosphate, Adenosine,Pyrophosphate, Adenosine