Expression of proliferating cell nuclear antigen in rat hearts subjected to transient ischemia followed by reperfusion
Tomiyasu Koyama, Zhonglin Xie, Jun’ichi Suzuki, Kazuhiro Abe

Early mechanisms involved in improving capillarity and oxygen transport to cardiac tissue exposed to transient coronary ischemia followed by reperfusion were studied in rats. Under ether anaesthesia, the left coronary artery was mechanically occluded for 3 min after which it was released, and the rats allowed to recover. After 2, 24 or 48 h the rats were sacrificed and the hearts frozen in liquid nitrogen. Frozen cross-sections were stained immunohistochemically for proliferating cell nuclear antigen (PCNA) and for the growth factors, VEGF and bFGF. No reaction for PCNA was seen in sections of sham-operated hearts but an inhomogeneous reaction occurred in annular structures in the occluded hearts at 48 h reperfusion. The stain appeared to be located in proliferating nuclei, and in the cytosol of endothelial cells. It is suggested that PCNA is stimulated by the increase in VEGF and bFGF that is known to occur within 2 h after the end of the coronary occlusion. It seems probable that the increase in capillaries observed in our previous study is associated with the nuclear proliferation of endothelial cells as shown by PCNA expression. Such an increase in capillaries would improve the transport of oxygen to cardiac tissue.

Keywords: heart, ischemia/reperfusion, proliferating cell nuclear antigen, capillarity, vascular growth factors

Applied Cardiopulmonary Pathophysiology 9: 378-381, 2000

Tomiyasu Koyama, M.D.
Third Dept. of Anatomy
School of Medicine
Hokkaido University
060 Sapporo
Japan