| Popis: |
Microvessels of the right atrium endothelium were investigated with electron microscope for patients with congenital heart disease receiving surgical treatment under deep perfusionless hypothermia and various methods of pharmaco-cold cardioplegia. In group 1, pharmaco-cold cardioplegia was performed, with hyperosmolar normopotash solution cooled down to 2-4 degrees C. In group 2, the same solution combined with isoptin, a potash-ion blocker, was applied. It has been shown that during global ischemia, stability of ion gradients on plasmalemma of endothelial cells is impaired, irrespective of the composition of cardioplegia solution. Alongside with this, ultrastructural reactions in group 1 proceed towards hyperosmia of endothelium accompanied by building up a large group of cells following coagulation necrosis. In group 2, by contrast, an intracellular edema progresses. The cardioprotective effect of isoptin, which is able to block Ca2+, manifests itself most vividly at reperfusion, when the blocking of cell potash overload prevents the development of dystrophic and destructive changes in endothelium of coronary microvessels, which present one of the most severe consequences in the process of blood flow recovery in ischemic tissues. |
