[Morphometric evaluation of adaptive responses of the sinoatrial node artery in dogs during various motor activity...

The reactions of the dog sinoatrial node artery under hyper- and hypokinesia were revealed by the serial semi-thin section morphometric analysis. Single maximal physical load may be a cause of the significant changes in the main source of blood supply of the dogs heart sinoauricular region. During 4 weeks hypokinezia structural and functional reserves of the artery were reduced. The following physical load caused significant reduction in the blood volume in the region of the right atrium of the heart. The individual peculiarities of the artery adaptive reactions are determined by the level of the heart functional activity and by the cardiac muscle metabolism. These factors should be taken into account when using maximal physical loads in clinic and experimental studies.