Light microscopy of sinoatrial node ischaemia.
Ischaemia of the sinoatrial node (SAN) region was produced in 57 dogs by obstructing the sinoatrial nodal artery by injecting it with various media. In the light microscope ischaemia of the nodal cells resulted in myocytolysis. The cells were oedematous, with a distinctly cleared cytoplasm and cytoplasmic vacuolization. Macrophages penetrated into the nodal cells. Myocytolysis resulted either in disintegration of the cell membrane and the nucleus or in atrophy of nodal cells. The damaged cells were gradually replaced with collagenous connective tissue. Ischaemic changes in the light microscope appeared between hours 3 to 24 after the onset of ischaemia and continued to develop for a period of 4 to 5 weeks showing a variable intensity in different areas of the SAN region. The process became virtually stabilized between months 1 to 7. The degree of ischaemia was most probably responsible for the fact that changes of various degree--myocytolysis, atrophy and fibrosis--were present simultaneously. The preservation of ganglion cells in ischaemic tissue is discussed.
Eliska
O
O
Department of Anatomy, Faculty of General Medicine, Charles' University, Prague, Czechoslovakia.
Elisková
M
M
D000818:Animals; D003326:Coronary Circulation; D003327:Coronary Disease / Q000473:pathology*; D003331:Coronary Vessels / Q000473:pathology; D004285:Dogs; D005260:Female; D008297:Male; D012849:Sinoatrial Node / Q000473:pathology*