[Some mechanisms of the development of endothelial disfunction in aging]. / Deiaki mekhanizmy rozvytku endotelial'noï dysfunktsiï pry starinni.

Taking into consideration age-related changes in endothelium, the ability of endothelium to produce vasoactive substances has been studied in healthy subjects of various age. Under experimental conditions, the activity of constitutive and inducible NO-synthase has been studied as well. The clinical part of the study involved investigation of 38 healthy subjects aged 60-79. The study has been designed to investigate vasomotor function of the endothelium, the levels of endothelin-1, NO2, prostacyclin, thromboxan, the level of adhesive molecules and inhibitor of tissue plasminogen activator. The levels of endothelial and inducible NO-synthases in tissues of the myocardium and the aorta has been investigated in healthy rats of various age. The data obtained show a decrease in the production of relaxation factors: NO and prostacyclin with aging. An important mechanism of deterioration of NO-synthesizing function of the endothelium is a decrease in endothelial NOS activity. The synthesis of endothelial vasoconstricting agents increased with ageing. This in combination with decreased production of vasodilating substances results in deterioration of defence properties of the endothelium. The increase in titer of adhesive molecules and inhibitors of tissue plasminogen activator testifies to age-dependent deterioration of anti-inflammatory and antithrombotic activities of the endothelium.

[Characteristics of hypoxia development in aged people]. / Osoblyvosti rozvytku hipoksiï u liudei litn'oho viku.

The aim of the study was to investigate the peculiarities of tissue oxygen provision on the level of microcirculatory bed and to determine the significance of the indices taken separatively in pathogenesis of hypoxia in practically healthy elderly people. The study comprised 30 practically healthy people aged 60-74. It included investigation of oxygen tension in peripheral tissues, skin and bulbar microcirculation, functional state of endothelium in the group of elderly healthy people. The results obtained were compared with analogous data obtained in practically healthy young subjects. The tissue oxygen provision was found to decrease with age.

[Circadian pattern features of paroxysmal atrial fibrillation in elderly patients with ischemic heart disease]. / Osoblyvosti dobovoho rozpodilu paroksyzmiv myhotlyvoï arytmiï u khvorykh na ishemichnu khvorobu sertsia pokhyloho viku.

Forty-eight elderly patients with IHD and paroxysmal atrial fibrillation were studied to determine circadian pattern of arrhythmia onset. The data were obtained by detailed interview and analysis of medical documents. The found variations were fitted to cosinusoidal function with a period of 24 hours Y = 9.75 + 3.5cos(2 pi t/24 + 0.2) (R2 = 0.69; F = 10.2; P < 0.01; two first coefficients of equation are significant by t-test, P < 0.01), the peak of arrhythmia onset was observed about midnight. 59.8% of overall number of episodes developed at dark period of day (P < 0.05). Findings testify that time periods of arrhythmia onset increase in number with disease evolution. It may be an additional criterion of paroxysmal atrial fibrillation transformation into its permanent form.