Influence of intracellular acidosis on contractile function in the working rat heart

Journal Article · Tue Dec 01 04:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:7026638

Jeffrey, F M.H.; Malloy, C R; Radda, G K ^[1]

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1. Univ. of Oxford (England)

The decrease in myocardial contractility during ischemia, hypoxia, and extracellular acidosis has been attributed to intracellular acidosis. Previous studies of the relationship between pH and contractile state have utilized respiratory or metabolic acidosis to alter intracellular pH. The authors developed a model in the working perfused rat heart to study the effects of intracellular acidosis with normal external pH and optimal O{sub 2} delivery. Intracellular pH and high-energy phosphates were monitored by {sup 31}P nuclear magnetic resonance spectroscopy. Hearts were perfused to a steady state with a medium containing 10 mM NH{sub 4}Cl. Acidosis induced a substantial decrease in aortic flow and stroke volume which was associated with little change in peak systolic pressure. It was concluded that (1) for the same intracellular acidosis the influence on tension development was more pronounced with a combined extra- and intracellular acidosis than with an isolated intracellular acidosis, and (2) stroke volume at constant preload was impaired by intracellular acidosis even though changes in developed pressure were minimal. These observations suggest that isolated intracellular acidosis has adverse effects on diastolic compliance and/or relaxation.

• OSTI ID: 7026638
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:6; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ACIDIFICATION
ALKALINE EARTH METAL COMPOUNDS
AMMONIUM CHLORIDES
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
ANIMALS
BIOCHEMISTRY
BIOLOGICAL EFFECTS
BLOOD PRESSURE
BODY
CALCIUM COMPOUNDS
CARDIOVASCULAR SYSTEM
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTS
HALIDES
HALOGEN COMPOUNDS
HEART
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MALES
MAMMALS
NONMETALS
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANS
OXYGEN
PH VALUE
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
RATS
RESONANCE
RODENTS
STABLE ISOTOPES
VERTEBRATES
VOLUME