Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (/sup 31/P NMR)
The authors assessed the metabolic and mechanical effects of changes in coronary perfusion pressure (CPP) and afterload (A) in isolated working apex-ejecting rat hearts perfused with Krebs-Henseleit solution containing an excess of O/sub 2/ and substrate. Log(phosphorylation potential) or log (ATP)/(ADP)x (Pi), designated (L), and log (PCR)/(Pi), designated (L*), were calculated from HPLC measurements after rapid freeze-clamping. Increasing CPP from 80-140 cm H/sub 2/O caused an increase in coronary flow(flow), developed pressure(DevP), O/sub 2/ consumption (VO/sub 2/), L, L*, and CO. L and L* were directly related to VO/sub 2/ and CO. Increasing A from 80-140 cm H/sub 2/O caused an increase in DevP and VO/sub 2/, but a decrease in L, L*, and CO. L and L* were inversely linearly related to VO/sub 2/ but were directly linearly related to CO. In both experiments, L and L* are directly related to CO, suggesting that determination of L* (which can be done with /sup 31/P NMR spectroscopy) may be a useful non-invasive method for determining cardiac pump function curves. L and L* may be related to the Frank-Starling mechanism. In a separate experiment using /sup 31/P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP caused a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique.
- Research Organization:
- Univ. of California, San Francisco
- OSTI ID:
- 6991953
- Report Number(s):
- CONF-8604222-
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:4; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
- Country of Publication:
- United States
- Language:
- English
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62 RADIOLOGY AND NUCLEAR MEDICINE
HEART
BLOOD FLOW
NMR SPECTRA
CORONARIES
LIQUID COLUMN CHROMATOGRAPHY
NUCLEAR MAGNETIC RESONANCE
PERFUSED ORGANS
PHOSPHORUS 31
PHOSPHORYLATION
RATS
ANIMALS
ARTERIES
BLOOD VESSELS
BODY
CARDIOVASCULAR SYSTEM
CHEMICAL REACTIONS
CHROMATOGRAPHY
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MAMMALS
NUCLEI
ODD-EVEN NUCLEI
ORGANS
PHOSPHORUS ISOTOPES
RESONANCE
RODENTS
SEPARATION PROCESSES
SPECTRA
STABLE ISOTOPES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques
550600 - Medicine