Three-dimensional microstructural abnormality of the coronary capillary network after myocardial reperfusion--comparison between 'reflow' and 'no-reflow'.
BACKGROUND
The 3-dimensional (D) structural abnormalities of the coronary capillary network and capillary volume changes after myocardial reperfusion were investigated using confocal laser scanning microscopy.


RESULTS
Using open-chest anesthetized rats' hearts, the left anterior descending artery (LAD) was occluded for 7 min followed by reperfusion. The hearts were divided into 2 groups: (1) reperfused area stained well by intravenous indocyanine green after reperfusion (Reflow), and (2) lack of staining in the reperfused area (No-reflow). The entire coronary microvasculature was filled with contrast medium using a Langendorff's perfusion system. Capillaries were observed 3-dimensionally in the control and reperfused areas in both the Reflow and No-reflow group and the capillary volume fraction was computed from the 3-D images. The reperfused area in both groups showed decreased capillary diameter with waving and shrinkage configuration. In the No-reflow group, marked interruption of capillary network was observed. In the Reflow group the capillary volume fraction was significantly reduced in the reperfused area compared with the control area (14.8+/-4.1% vs 22.2+/-5.6%, p<0.05). Capillary volume fraction was further decreased in the No-reflow group compared with Reflow (5.3+/-1.4% vs 14.8+/-4.1%, p<0.01).


CONCLUSIONS
The morphological changes in coronary capillaries after reperfusion were characterized by waving and shrinkage, which resulted in a reduction in capillary volume.
Department of Cardiology, Kawasaki Medical School, Kurashiki, Japan. non@med.kawasaki-m.ac.jp
Nozomi
N
Watanabe
Takashi
T
Akasaka
Eiji
E
Toyota
Katsukuni
K
Fujimoto
Tatsuya
T
Kajita
Fumiyuki
F
Shigeto
Yasuo
Y
Ogasawara
Kiyoshi
K
Yoshida
D000818:Animals; D002196:Capillaries / Q000473:pathology*; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000033:anatomy & histology*; D004195:Disease Models, Animal; D008297:Male; D018613:Microscopy, Confocal; D015425:Myocardial Reperfusion / Q000009:adverse effects / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar