Intracellular pH and inorganic phosphate content of heart in vivo: A sup 31 P-NMR study

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:6834448

Katz, L A; Swain, J A; Portman, M A; Balaban, R S ^[1]

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1. National Heart, Lung, and Blood Institute, Bethesda, MD (USA)

Studies were performed to determine the contribution of red blood cells to the {sup 31}P-nuclear magnetic resonance (NMR) spectrum of the canine heart in vivo and the feasibility of measuring myocardial intracellular phosphate and pH. This was accomplished by replacing whole blood with a perfluorochemical perfusion emulsion blood substitute, Oxypherol, and noting the difference in the {sup 31}P-NMR spectrum of the heart. NMR data were collected with a NMR transmitter-receiver coil on the surface of the distal portion of the left ventricle. These studies demonstrated that a small contribution from 2,3-diphosphoglycerate (2,3-DPG) and phosphodiesters in the blood could be detected. The magnitude and shift of these blood-borne signals permitted the relative quantification of intracellular inorganic phosphate (P{sub i}) content as well as intracellular pH. Under resting conditions, the intracellular ATP/P{sub i} was 7.0 {plus minus} 0.08. This corresponds to a free intracellular P{sub 1} content of {approx} 0.8 {mu}mol./g wet wt. The intracellular pH was 7.10 {plus minus} 0.01. Acute respiratory alkalosis and acidosis, with the arterial pH ranging from {approximately}7.0 to 7.7, resulted in only small changes in the intracellular pH. These latter results demonstrate an effective myocardial intracellular proton-buffering mechanism in vivo.

• OSTI ID: 6834448
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:1; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BIOCHEMISTRY
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BLOOD SUBSTITUTES
BODY
BODY FLUIDS
CARDIOVASCULAR SYSTEM
CHEMISTRY
DOGS
DRUGS
ERYTHROCYTES
ESTERS
HEART
HEMATOLOGIC AGENTS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MAMMALS
MATERIALS
MUSCLES
MYOCARDIUM
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PH VALUE
PHOSPHORUS 31
PHOSPHORUS ISOTOPES
RESONANCE
STABLE ISOTOPES
VERTEBRATES