-transparent.png){kind=logo}
In view of its vasodilatory effect on the coronary circulation (probably mediated by adenosine) and its metabolic compartmentalization (intramitochondrial activation to form acetyl-CoA), the metabolic effects of acetate were studied in isolated rat heart mitochondria. Acetate caused conversion of adenylates to AMP and the formation of adenosine. Adenylate efflux was inhibited by carboxyatractyloside but not by N-ethylmaleimide. The intramitochondrial accumulation of AMP was enhanced by carboxyatractyloside during acetate metabolism and the formation of extramitochondrial adenosine inhibited. A carboxyatractyloside-sensitive unidirectional AMP influx with a Km of 50 microM and Vmax of 11 nmol/min per mg mitochondrial protein was also observed. The mitochondrial adenosine content was high and constant during the experiments. The steep apparent concentration gradient of adenosine indicates that most of the mitochondrial adenosine is tightly bound to protein. Adenosine formation was proportional to the extramitochondrial AMP concentration, showing that the 5'-nucleotidase activity of cardiac mitochondrial preparations is extramitochondrial in origin. The data suggest that the mitochondrial ATP/ADP carrier is capable of transporting AMP and that intramitochondrial AMP is recycled during acetate metabolism in the myocardium partially by means of the ATP/ADP translocator, leading to an increase in extramitochondrial AMP and adenosine formation.
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
June 1993,
Archives of biochemistry and biophysics,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
May 1984,
Circulation research,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
October 1986,
Biochimica et biophysica acta,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
September 1979,
Biochemistry,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
September 1980,
Bulletin of environmental contamination and toxicology,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
August 1977,
The Journal of biological chemistry,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
January 1976,
Voprosy biokhimii mozga,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
August 1986,
Cardiovascular research,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
August 1979,
Circulation research,
K T Kiviluoma, and
K J Peuhkurinen, and
I E Hassinen
February 1985,
Biokhimiia (Moscow, Russia),
