[Muscle blood flow in healthy persons of different ages]. / Myshechnyi krovotok u zdorovykh liudei raznogo vozrasta.

A study was made of the muscular blood flow at rest (MBFR) and in reactive hyperemia (MMBF--maximum muscular blood flow) in 170 healthy persons using a method of local clearance with 133Xe. The results of the study showed a regular decrease in the MBFR and MMBF level in aging, the decrease rates of MMBF considerably prevailing over those of MBFR. In the age interval between 18-96 MBFR lessens by 24%, MMBF more than twice. The age-associated time course of MMBF is of a more complicated nature as compared to that of MBRF and indicates a considerable reduction of the functional reserves of the tissue blood flow in the skeletal muscles of middle-aged and old persons. The above data make it possible to outline MBFR rough standard values: for young persons--2.5-5.0 ml/100 g/min., for older persons--1.5-3.5 ml/100 g/min. As normal MBFR fluctuations in healthy persons one can adopt a +/- 20% interval of respective MBRF mean values in each decade. MBF age-associated changes should be regarded in the diagnosis of obliterating lesions of lower limb vessels and other diseases accompanied by its decrease. Special emphasis should be placed on MMBF.

[Age-associated peculiarities of microcirculation system in skeletal muscles and their role in muscle work capacity in human aging (author's transl)]. / Die alternsbesonderheiten des Systems der Mikrozirkulation in den Skelettmuskeln und ihre Rolle in der Arbeitsfähigkeit des Muskels beim Altern des Menschen.

The muscle blood flow was investigated at rest (MBFR) and after physical load under ischemia conditions (maximal muscle blood flow--MMBF) in 87 practically healthy persons (45 women and 42 men) aged 20--90. The state of muscle blood flow was evaluated by means of the clearance of 133xenon injected into M. tibialis anterior. The data obtained showed a decrease of MBFR and MMBF in older people as compared with younger subjects. In realization of this phenomenon a decrease in muscle capillarisation and a reduction in reactivity of microcirculatory link of vascular system plays an increasingly greater role with aging. The reduction in muscle blood flow forms a circulatory component of the age-associated hypoxia. This fact results in a decrease of muscle blood flow and limits the functional capacity of skeletal muscle under conditions of activity.

[Age-specific characteristics of microcirculation in middle-and old age]. / Vozrastnye osobennosti sistemy mikrotsirkuliatsii v pozhilom i starcheskom vozraste

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.