Myocardial metabolism during hypoxia: Maintained lactate oxidation during increased glycolysis

Journal Article · Sat Sep 01 00:00:00 EDT 1990 · Metabolism, Clinical and Experimental; (USA)

DOI:https://doi.org/10.1016/0026-0495(90)90300-2· OSTI ID:6510851

Mazer, C D; Stanley, W C; Hickey, R F; Neese, R A; Cason, B A; Demas, K A; Wisneski, J A; Gertz, E W ^[1]

---

1. Univ. of California, San Francisco (USA)

In the intact animal, myocardial lactate utilization and oxidation during hypoxia are not well understood. Nine dogs were chronically instrumented with flow probes on the left anterior descending coronary artery and with a coronary sinus sampling catheter. ({sup 14}C)lactate and ({sup 13}C)glucose tracers, or ({sup 13}C)lactate and ({sup 14}C)glucose were administered to quantitate lactate and glucose oxidation, lactate conversion to glucose, and simultaneous lactate extraction and release. The animals were anesthetized and exposed to 90 minutes of severe hypoxia (PO2 = 25 +/- 4 torr). Hypoxia resulted in significant increases in heart rate, cardiac output and myocardial blood flow, but no significant change in myocardial oxygen consumption. The arterial/coronary sinus differences for glucose and lactate did not change from normoxia to hypoxia; however, the rate of glucose uptake increased significantly due to the increase in myocardial blood flow. Tracer-measured lactate extraction did not decrease with hypoxia, despite a 250% increase in lactate release. During hypoxia, 90% +/- 4% of the extracted {sup 14}C-lactate was accounted for by the appearance of {sup 14}CO{sub 2} in the coronary sinus, compared with 88% +/- 4% during normoxia. Thus, in addition to the expected increase in glucose uptake and lactate production, we observed an increase in lactate oxidation during hypoxia.

• OSTI ID: 6510851
• Journal Information: Metabolism, Clinical and Experimental; (USA), Vol. 39:9; ISSN 0026-0495
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
GLUCOSE
METABOLISM
LACTATES
MYOCARDIUM
ACETATES
ANOXIA
BLOOD FLOW
BLOOD PRESSURE
CARBON 13
CARBON 14 COMPOUNDS
CORONARIES
DOGS
ISOTOPE DILUTION
ALDEHYDES
ANIMALS
ARTERIES
BLOOD VESSELS
BODY
CARBOHYDRATES
CARBON ISOTOPES
CARBOXYLIC ACID SALTS
CARDIOVASCULAR SYSTEM
EVEN-ODD NUCLEI
HEART
HEXOSES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
LIGHT NUCLEI
MAMMALS
MONOSACCHARIDES
MUSCLES
NUCLEI
ORGANIC COMPOUNDS
ORGANS
SACCHARIDES
STABLE ISOTOPES
TRACER TECHNIQUES
VERTEBRATES
550501* - Metabolism- Tracer Techniques