A model of acute regional myocardial ischemia and reperfusion in the rat.
Studies were conducted in 76 rats to describe and validate a new closed-chest in vivo model for acute ischemia and reperfusion of the left coronary artery. Radiolabeled microsphere distribution in six rat hearts confirmed a significant reduction in arteriolar flow at the center of the ischemic zone (93% reduction of total myocardial counts compared to nonischemic region, P less than 0.01) after 7 min of occlusion. Arteriolar flow returned to control values upon reperfusion. While hemodynamic parameters in 10 rats during 7 min of occlusion and 7 min of reperfusion were monitored, end diastolic pressures increased significantly (P less than 0.01) during occlusion. Finally, the utility of this rat model was demonstrated in a study of contrast enhanced magnetic resonance imaging (N = 4). Normal myocardium could not be differentiated from acutely ischemic myocardium on noncontrast-enhanced MR images. After 5 min of myocardial ischemia and following contrast administration (albumin-Gd-DTPA), the ischemic zone appeared less enhanced than normal myocardium. Upon release of the occluder the left ventricular free wall once again yielded a homogeneous signal similar to that of the normal myocardium.
Sievers
R E
RE
Cardiovascular Research Institute, University of California, School of Medicine, San Francisco 94143.
Schmiedl
U
U
Wolfe
C L
CL
Moseley
M E
ME
Parmley
W W
WW
Brasch
R C
RC
Lipton
M J
MJ
D000818:Animals; D003327:Coronary Disease / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D008279:Magnetic Resonance Imaging; D008863:Microspheres; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains