title: Release of AMP and adenosine from rat heart mitochondria.
abstract: Release of AMP and adenosine from rat heart mitochondria was studied. The rate of appearance of extramitochondrial adenosine was independent of the extramitochondrial phosphate concentration between 5 and 20 mM. In the absence of exogenous, respiratory substrates or in the presence of glutamate/malate plus rotenone, the rate of appearance of adenosine was relatively low when phosphate was not added. The appearance of extramitochondrial AMP + adenosine was found to be directly proportional to the extra-mitochondrial phosphate concentration. Zn2+ (10 mM) decreased the rate of adenosine appearance by 90% and increased the rate of AMP appearance 6-fold. The mitochondrial preparations dephosphorylated exogenous AMP; this activity was inhibited by 10 mM Zn2+. We conclude that the adenosine appearing in the extramitochondrial space was not due to a direct release from the matrix, but instead was due to adenine nucleotide release with subsequent conversion to adenosine in the extramitochondrial space.
authors.forename: G K
authors.initials: GK
authors.lastname: Asimakis
authors.forename: D E
authors.initials: DE
authors.lastname: Wilson
authors.forename: V R
authors.initials: VR
authors.lastname: Conti
mesh_terms: D015720:5'-Nucleotidase; D000241:Adenosine / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000378:metabolism*; D000818:Animals; D004492:Edetic Acid / Q000494:pharmacology; D005971:Glutamates / Q000494:pharmacology; D018698:Glutamic Acid; D007700:Kinetics; D008293:Malates / Q000494:pharmacology; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D009532:Nickel / Q000494:pharmacology; D009708:Nucleotidases / Q000037:antagonists & inhibitors; D010710:Phosphates / Q000494:pharmacology; D051381:Rats; D012402:Rotenone / Q000494:pharmacology; D015032:Zinc / Q000494:pharmacology
chemical_list: D005971:Glutamates; D008293:Malates; D010710:Phosphates; D012402:Rotenone; D018698:Glutamic Acid; D000249:Adenosine Monophosphate; D009532:Nickel; C030298:malic acid; D004492:Edetic Acid; D009708:Nucleotidases; D015720:5'-Nucleotidase; D015032:Zinc; D000241:Adenosine