PMID- 8769754
OWN - NLM
STAT- MEDLINE
DCOM- 19961220
LR  - 20171213
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 270
IP  - 1 Pt 2
DP  - 1996 Jan
TI  - Developmental changes in ATP utilization during graded hypoxia and reoxygenation 
      in the heart in vivo.
PG  - H216-23
AB  - Myocardial ATP utilization and resynthesis during hypoxia and reoxygenation were 
      studied in vivo as a function of maturation. Graded hypoxia was performed in 
      newborn (NB; 4-10 days old, n = 6) and mature sheep (MAT; 30-60 days old, n = 6). 
      Time-resolved 31P-nuclear magnetic resonance was used to monitor myocardial 
      phosphates throughout hypoxia and to monitor reoxygenation concomitant with rate 
      of myocardial O2 consumption (MVO2) measurement. Oxygen delivery and MVO2 were 
      constant in both groups throughout hypoxia, with substantial and similar 
      increases in both parameters during reoxygenation. Hypoxic myocardial lactate 
      release was similar in NB and MAT. Phosphocreatine (PCr), but not ATP, decreased 
      in NB only during milder hypoxia. Rapid PCr and slower ATP depletion occurred 
      with severe hypoxia, consistent with ATP utilization/synthesis imbalance. 
      Depletion rates were higher in MAT. Creatine rephosphorylation rates, measures of 
      mitochondrial function reported as percentage of predicted values, were similar. 
      34 +/- 12 in NB and 26 +/- 9% in mature lambs. In conclusion, 1) phosphorylation 
      potential decreases in NB but not MAT in response to a decreasing oxygen 
      gradient; 2) ATP utilization during hypoxia increases more in mature lambs; 3) 
      anaerobic ATP production is not greater in NB; and 4) despite the greater energy 
      imbalance imposed on MAT during hypoxia, mitochondrial function is similar to NB 
      during reoxygenation.
FAU - Portman, M A
AU  - Portman MA
AD  - Department of Pediatrics, University of Washington, Seattle, USA.
FAU - Standaert, T A
AU  - Standaert TA
FAU - Ning, X H
AU  - Ning XH
LA  - eng
GR  - R29-HL-47805/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (Gases)
RN  - 0 (Lactates)
RN  - 0 (Phosphates)
RN  - 27YLU75U4W (Phosphorus)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Adenosine Triphosphate/*metabolism
MH  - Aging/*metabolism
MH  - Animals
MH  - Animals, Newborn/growth & development
MH  - Biological Availability
MH  - Energy Metabolism
MH  - Gases/blood
MH  - Hemodynamics
MH  - Hydrogen-Ion Concentration
MH  - Hypoxia/*metabolism
MH  - Lactates/metabolism
MH  - Myocardium/*metabolism
MH  - Oxygen/blood
MH  - *Oxygen Consumption
MH  - Phosphates/metabolism
MH  - Phosphorus
MH  - Sheep
EDAT- 1996/01/01 00:00
MHDA- 1996/01/01 00:01
CRDT- 1996/01/01 00:00
PHST- 1996/01/01 00:00 [pubmed]
PHST- 1996/01/01 00:01 [medline]
PHST- 1996/01/01 00:00 [entrez]
AID - 10.1152/ajpheart.1996.270.1.H216 [doi]
PST - ppublish
SO  - Am J Physiol. 1996 Jan;270(1 Pt 2):H216-23. doi: 
      10.1152/ajpheart.1996.270.1.H216.