[Adaptive structures of the arteries of the heart participating in the regulation of coronary circulation].

By means of a complex of anatomical, histological and histochemical methods cardiac vessels have been studied in 20 control dogs and in 84 dogs with experimentally produced circulatory disturbances peculiar for congenital heart diseases presented as an open arterial duct, coarctation of the aorta and the pulmonary trunk stenosis. The experimental animals have been observed for 6-12 months. In the animals with experimentally produced disturbances of the general and coronary hemodynamics hyperplasy in the coronary branches of the arteries appears, it is more pronounced in functionally loaded cardiac parts, as well as thickening of their walls at the expense of new formations and hyperthrophy of smooth muscle cells. In both control and experimental dogs in the coronary vessels at various branching levels certain formations are revealed; they are of compensatory-adaptive value: intimal and adventitial musculature, polypoid pulvinars, muscular-elastic constrictors, muscular cuffs and precapillary sphincters. They differ in structure, sources of their origin and in their functional value. Degree of their manifestation increases significantly after reproduction of the hemodynamic disturbances in the heart vascular system. The active role of these formations in regulation of the coronary circulation is demonstrated owing to a high content of ribonucleinic acid and glycogene in their smooth muscle cells and also an elevated succinate dehydrogenase, cytochromoxydase, acid and alcaline phosphatase activities.