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Title: Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (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 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 31-P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP causedmore » a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique.« less
Authors:
; ; ; ; ; ; ;
Publication Date:
OSTI Identifier:
6915811
Report Number(s):
CONF-8604222-
Journal ID: CODEN: FEPRA; TRN: 87-005913
Resource Type:
Conference
Resource Relation:
Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States); Journal Volume: 45:4; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
Research Org:
Univ. of California, San Francisco
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; HEART; BLOOD FLOW; NMR SPECTRA; ADP; ATP; BLOOD PRESSURE; LIQUID COLUMN CHROMATOGRAPHY; OXYGEN; PERFUSED ORGANS; PHOSPHORUS 31; PHOSPHORYLATION; RATS; ANIMALS; BODY; CARDIOVASCULAR SYSTEM; CHEMICAL REACTIONS; CHROMATOGRAPHY; ELEMENTS; ISOTOPES; LIGHT NUCLEI; MAMMALS; NONMETALS; NUCLEI; NUCLEOTIDES; ODD-EVEN NUCLEI; ORGANIC COMPOUNDS; ORGANS; PHOSPHORUS ISOTOPES; RODENTS; SEPARATION PROCESSES; SPECTRA; STABLE ISOTOPES; VERTEBRATES 550601* -- Medicine-- Unsealed Radionuclides in Diagnostics