Dynamic mechanisms of cardiac oxygenation during brief ischemia and reperfusion

Journal Article · Thu Nov 01 04:00:00 EST 1990 · American Journal of Physiology; (USA)

OSTI ID:6070349

Parsons, W J; Rembert, J C; Bauman, R P; Greenfield, Jr, J C; Piantadosi, C A ^[1]

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1. Duke Univ., Durham (USA)

Myocardial oxygenation may be altered markedly by changes in tissue blood flow. During brief ischemia and reperfusion produced by transient occlusion of the left anterior descending artery in 10 open-chest dogs, changes in the oxygenation of tissue hemoglobin (Hb) plus myoglobin (Mb) and the oxidation-reduction (redox) state of mitochondrial cytochrome aa3 were monitored continuously using near-infrared spectroscopy. The nondestructive optical technique indicated that coronary occlusion produced an abrupt drop in tissue oxygen stores (tHb02 + Mb02), tissue blood volume (tBV), and the oxidation level of cytochrome aa3. Changes in the cytochrome oxidation state were related inversely to transmural collateral blood flow within the ischemic region (r = 0.77) measured with radiolabeled microspheres. Furthermore, there was a direct relationship (r = 0.91) between collateral blood flow and the tissue level of desaturated Hb and Mb (tHb + Mb). Reperfusion after 2 min of ischemia led to a synchronous overshoot of baseline in coronary flow and tBV followed by supranormal increases in tHb + Mb02 and the oxidation level of cytochrome aa3. The tHb + Mb level increased transiently during reperfusion. This response correlated inversely with collateral flow during ischemia (r = 0.91). Accordingly, the time required to reach peak tHb + Mb levels was shortest in dogs with high collateral flows (r = 0.75). Thus collateral blood flow partially sustains myocardial oxygenation during coronary artery occlusion and influences tissue reoxygenation early during reperfusion.

• OSTI ID: 6070349
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 259:5 Pt 2; 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
BLOOD FLOW
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CHEMICAL REACTIONS
CYTOCHROMES
DISEASES
DYNAMIC FUNCTION STUDIES
ELEMENTS
GLOBINS
HEART
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFRARED SPECTRA
ISCHEMIA
MICROSPHERES
MITOCHONDRIA
MUSCLES
MYOCARDIUM
MYOGLOBIN
NONMETALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANOIDS
ORGANS
OXYGEN
PIGMENTS
PORPHYRINS
PROTEINS
REDOX REACTIONS
SPECTRA
VASCULAR DISEASES