[Age-specific characteristics of microcirculation in middle-and old age]

The results subsequent to investigations of morphological and functional peculiarities specific for cutaneous capillary circulation in the nailbed of hand and foot fingers of practically healthy young individuals (18--30 years old) and physiologically ageing persons (aged over 60) are reported. In ageing of humans there is demonstrable fading and opacification of the capillaroscopic field of vision background, flattening out of the papillary layer, diminution in the number of functioning capillaries per unit of the skin surface, the presence of non-vascularized zones, the development of intercapillary autoanastomoses and of the subpapillary venous plexus, lengthening of arterial and venous capillary branches, prevalence of spastico-atonic and spastic forms of the capillary loops, slowing down and granular nature of the capillary blood flow. With growing age there become evident a reduction of functioning reserve capillaries, a depression of the skin capillaries sensitivity to the neural effects (heat and cold) and its increase to humoral (adrenalin, histamine, acetylcholine and hypophysin ones. The mechanism behind the said phenomena in ageing is considered. The data obtained are of significance in studying the mechanisms underlying the ageing of the organs and tissues, the understanding of age-specific features of the pathogenesis, evolution and treatment of a number of affections involving the cardiovascular system in persons of advanced and senile age.