Effect of systemic pH on pH sub i and lactic acid generation in exhaustive forearm exercise

Journal Article · Thu Sep 01 00:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:6896308

Hood, V L; Schubert, C; Keller, U; Mueller, S ^[1]

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1. Univ. of Basel (Switzerland) Univ. of Vermont College of Medicine, Burlington (USA)

To investigate whether changes in systemic pH affect intracellular pH (pH{sub i}), energy-rich phosphates, and lactic acid generation in muscle, eight normal volunteers performed exhaustive forearm exercise with arterial blood flow occluded for 2 min on three occasions. Subjects ingested 4 mmol/kg NH{sub 4}Cl (acidosis; A) or NaHCO{sub 3} (alkalosis; B) or nothing (control; C) 3 h before the exercise. Muscle pH{sub i} and phosphocreatine (PCr) content were measured with {sup 31}P-nuclear magnetic resonance ({sup 31}P-NMR) spectroscopy during exercise and recovery. Lactate output during 0.5-7 min of recovery was calculated as deep venous-arterial concentration differences times forearm blood flow. Before exercise, blood pH and bicarbonate were lower in acidosis than alkalosis and intermediate in control. Lactic acid output during recovery was less with A than B and intermediate in C. PCr utilization and resynthesis were not affected by extracellular pH changes. pH{sub i} did not differ before exercise or at its end. Hence systemic acidosis inhibited and alkalosis stimulated lactic acid output. These findings suggest that systemic pH regulates cellular acid production, protecting muscle pH, at the expense of energy availability.

• OSTI ID: 6896308
• Journal Information: American Journal of Physiology; (USA), Vol. 255:3; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
EXERCISE
BIOLOGICAL EFFECTS
LACTIC ACID
METABOLISM
MUSCLES
PH VALUE
PHOSPHOCREATINE
NUCLEAR MAGNETIC RESONANCE
AMMONIUM CHLORIDES
ARMS
BLOOD FLOW
MEN
PHOSPHORUS 31
PROTONS
SODIUM CARBONATES
ALKALI METAL COMPOUNDS
AMINO ACIDS
AMMONIUM COMPOUNDS
AMMONIUM HALIDES
ANIMALS
BARYONS
BODY
BODY AREAS
CARBON COMPOUNDS
CARBONATES
CARBOXYLIC ACIDS
CHLORIDES
CHLORINE COMPOUNDS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
HALIDES
HALOGEN COMPOUNDS
HYDROXY ACIDS
ISOTOPES
LIGHT NUCLEI
LIMBS
MAGNETIC RESONANCE
MALES
MAMMALS
MAN
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORUS ISOTOPES
PRIMATES
RESONANCE
SODIUM COMPOUNDS
STABLE ISOTOPES
VERTEBRATES
550601* - Medicine- Unsealed Radionuclides in Diagnostics