AJP - Heart and Circulatory Physiology, Vol 242, Issue 6 980-H989, Copyright © 1982 by American Physiological Society
Regional myocardial function and metabolism during acute coronary artery occlusion
H. Kanaide, R. Yoshimura, N. Makino and M. Nakamura
Regional changes in myocardial function and oxidative metabolism during
acute coronary artery occlusion were recorded spectrophotometrically by
incorporating fiber optics in the isolated rat heart perfused by
Langendorff's procedure. Oxygen saturation of myoglobin, reduction of
cytochrome aa3, and the dynamic wall thickness of the left ventricle were
continuously and concurrently measured from absorbancy increments at
581-592 nm, 605-630 nm, and 568-592 nm, respectively. In contrast to a
gradual decrease in the extent of systolic wall thickening in anoxia,
observed decreases in both the extent and the duration of systolic wall
thickening and the appearance of a late systolic bulge occurred within 5 s
after the onset of regional ischemia. After 10 s of both anoxia and
regional ischemia, oxygen saturation of myoglobin decreased by 50%, but
fluorescence of nicotinamide adenine dinucleotide remained at aerobic level
which indicated that mitochondrial oxidative energy production might still
be maintained. Thus early and pronounced dysfunction of the ischemic region
appeared to precede a substantial loss of ATP production.
