skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR)

Abstract

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:
Research Org.:
Univ. of California, San Francisco
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
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

Citation Formats

Watters, T., Wikman-Coffelt, J., Wu, S., Wendland, M., James, T., Sievers, R., Botvinick, E., and Parmley, W. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR). United States: N. p., 1986. Web.
Watters, T., Wikman-Coffelt, J., Wu, S., Wendland, M., James, T., Sievers, R., Botvinick, E., & Parmley, W. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR). United States.
Watters, T., Wikman-Coffelt, J., Wu, S., Wendland, M., James, T., Sievers, R., Botvinick, E., and Parmley, W. 1986. "Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR)". United States. doi:.
@article{osti_6915811,
title = {Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR)},
author = {Watters, T. and Wikman-Coffelt, J. and Wu, S. and Wendland, M. and James, T. and Sievers, R. and Botvinick, E. and Parmley, W.},
abstractNote = {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 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.},
doi = {},
journal = {Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)},
number = ,
volume = 45:4,
place = {United States},
year = 1986,
month = 3
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • 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 causedmore » 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.« less
  • The authors have used an isolated perfused heart system for characterizing potential myocardial perfusion radiopharamaceuticals. Rabbit or guinea pig (GP) hearts are removed and perfused through the aorta with a blood-free buffer. Heart rate and ventricular pressure are monitored as indices of viability. Tc-99m-MAA is 96-100% retained in these hearts, and Tc-99m human serum albumin shows less than 5% extraction. Tl-201 is 30-40% extracted. It is known that in-vivo, Tc-99m(dmpe)/sub 2/Cl/sub 2//sup +/ is taken up by rabbit heart but not by GP or human heart. Analogous results are obtained with the isolated perfused heart model, where the complex ismore » extracted well by the isolated rabbit heart (24%) but not by the GP heart (<5%). Values are unchanged if human, rabbit or GP blood is mixed and co-injected with the complex. Tc-99m)dmpe)/sub 3//sup +/ is also taken up by rabbit but not by GP hearts in-vivo. However, isolated perfused hearts of both species extract this complex well (45-52%). Heart uptake is diminished to <7% if the complex is pre-equilibrated with human blood. GP blood produces a moderate inhibition (in GP hearts only) and rabbit blood has no effect. This suggests that a human or GP blood factor may have a significant effect on heart uptake of this complex. Tc-99m(CN-t-butyl)/sub 6//sup +/ is taken up well by both rabbit and GP hearts in-vivo, and is extracted 100% by both isolated perfused hearts. Heart retention remains high (73-75%) in the presence of human blood.« less
  • To study the myocardial washout of ascorbate, the applicability of polarographic detection of ascorbate ions by a platinum electrode (sensitive area 0.03 mm2) was investigated, in both a calibration setup (sampling flow along the electrode: 100 microliter X s-1) and isolated, retrogradely perfused rabbit hearts. In the calibration setup at pH 7.4, the sensitivity of the electrode was 70 microA/mol. This sensitivity increased moderately with increasing pH (13%/unit pH) and increasing sampling flow rate (14% at an increase from 100 to 150 microliter X s-1). In the isolated hearts, ascorbate infused into the aorta was detected in a right ventricularmore » drain by the electrode as well as by the use of /sup 14/C-labeled ascorbate. Both recorded time courses were similar except for a scaling factor dependent on flow velocity. During continuous infusion the arteriovenous difference of ascorbate was 2 +/- 2% (SD), indicating a relatively low consumption of ascorbate by the isolated heart. The authors conclude that polarographic measurement of ascorbate in the coronary effluent of an isolated rabbit heart can be performed on-line and relatively easily.« less
  • Transient exposure of an isolated isovolumic perfused rat heart to low concentrations (0.5 mM) of perfusate-born iodoacetamide resulted in complete inhibition of creatine kinase and partial inhibition of glyceraldehyde-3-phosphate dehydrogenase in the heart. At low levels of developed pressure, hearts maintained mechanical function, ATP, and creatine phosphate levels at control values. However, iodoacetamide-inhibited hearts were unable to maintain control values of end diastolic pressure or peak systolic pressure as work load increased. Global ischemia resulted in loss of all ATP without loss of creatine phosphate, indicating lack of active creatine kinase. These results indicate that isovolumic perfused rat hearts aremore » able to maintain normal function and normal levels of high-energy phosphates without active creatine kinase at low levels of developed pressure. /sup 31/P-NMR of the heart was carried out.« less
  • Isolated guinea pig hearts were prelabeled with /sup 3/H-norepinephrine (/sup 3/H-NE) and perfused with modified Krebs-bicarbonate solution at 37/sup 0/C. Spontaneous release of total /sup 3/H and field stimulation-mediated (supramax. V., 1 Hz, 2 msec duration for a total of 60 pulses) overflow of NE and /sup 3/H-NE were measured in the absence or presence of etorphine. Etorphine (0.1 - 100 ..mu..M) was added to the perfusion fluid 15 min. before the stimulation. To study the effect of etorphine on spontaneous release of total /sup 3/H, etorphine was added cumulatively without stimulation. Etorphine (1.0 - 100 ..mu..M) caused a significantmore » decrease in the stimulation-mediated overflow of NE and the inhibition was dose-related. The overflow of NE was 5.1 +/- 0.3 ng in the absence and 4.0 +/- 0.2 ng in the presence of etorphine (1.0 ..mu..M). Low concentrations of etorphine (0.1 - 1.0 ..mu..M) had no effect on the spontaneous release of total /sup 3/H while 10 ..mu..M and 100 ..mu..M caused a 3 and 6-fold increase respectively. The results show that etorphine inhibited neuronal release of NE at a dose which had no effect on spontaneous release. It is suggested that opiate receptors might be involved in the prejunctional modulation of the release of NE in the guinea pig heart.« less