Rate of ATP synthesis in the perfused rat liver by 31P cryo-NMR.
ATP concentrations in the perfused rat liver during normoxic perfusion, transient ischemia, and recovery from transient ischemia were measured using the modified 31P cryo-NMR method (Chance, B., Nakase, Y., Bond, M., Leigh, J. S., Jr., and McDonald, G. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 4925-4929). Transient ischemia was induced in the perfused livers of starved rats, and multiple freeze-trapped tissue samples were taken from each liver at short intervals (15-30 s) during ischemia or following reperfusion. The freeze-trapped tissue was pulverized together with an antifreezing agent and high energy metabolites were measured by 31P NMR at 243 K after thawing. By using the cryo-NMR technique, a biochemical time resolution of 2 s could be achieved. Absolute metabolite concentrations were calculated by comparing the peak areas with internal standards mixed into the samples. Good time resolution and reliable concentration measurements provided by the cryo-NMR method enable us to estimate the ATP synthesis rate in the perfused liver during reperfusion following transient ischemia. The rate of ATP synthesis in the normoxic perfusion was 1.95 mumol/min/g wet weight; the maximal ATP synthesis rate during the recovery phase from ischemia was 5.75 mumol/min/g wet weight.
Ikai
I
I
Department of Biochemistry and Biophysics, School of Medicine, University of Pennsylvania, Philadelphia 19104.
Okuda
M
M
Doliba
N
N
Chance
B
B
D000255:Adenosine Triphosphate / Q000096:biosynthesis*; D000818:Animals; D005615:Freezing; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D010477:Perfusion; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus; D051381:Rats; D011919:Rats, Inbred Strains
D010710:Phosphates; D010758:Phosphorus; D000255:Adenosine Triphosphate