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27 patients with dilated cardiomyopathy (DCM) complicated by heart failure (HF) of stages I-IIB were studied. The density of lymphocyte beta 2-adrenoceptors decreased significantly as HF progressed. The level of circulating catecholamines (epinephrine, norepinephrine) was significantly higher in patients were severe HF, which probably caused more evident decrease in lymphocyte beta 2-adrenoceptors density in these patients. This point of view was confirmed by the data of correlation-regression analysis between the general beta 2-adrenoceptors density and hemodynamics data. The identified changes in the number of adrenoceptors reflect the process of cellular receptors desensitization. They should be considered as a possible mechanism of HF development on a molecular level that cause development of refractoriness to routine therapy.

Effects of dynamic exercise on lymphocyte beta 2-adrenoreceptor density (BARD) and adenylate cyclase activity (ACA) basal and stimulated by isoproterenol (I). Gpp(NH)p, Gpp(NH)p+I, and forskolin (F), on plasma adrenaline and noradrenaline levels, renin activity (PRA) were compared in 6 healthy donors and 12 patients with essential hypertension (EH). Acute stimulation of sympathetic activity by dynamic exercise leads to a rapid increase in lymphocyte BARD in normotensive and hypertensive subjects. The rise in BARD was accompanied by a significant increase in lymphocyte basal ACA in normotensive subjects, but not hypertensive patients. In patients with EH, basal ACA changed after exercise according to their renin status: patients with low baseline PRA showed a decrease in basal ACA after exercise, whereas patients with normal baseline PRA showed an increase as did normotensive subjects. Patients with decreased basal ACA after exercise also showed a lower ACA stimulation by IPR, F, Gpp (NH)p and Gpp(NH)p+IPR, which did not change after exercise. These patients also exhibited substantial rises in PRA with exercise. These was an inverse relationship between exercise-induced changes in PRA and basal ACA. So the acute regulation of lymphocyte BARD-ACA system is changed in a subset of patients with EH. The pattern of the regulation of this lymphocyte system is associated that of baseline renin activity and of its response to exercise in patients with EH.

Lymphocyte beta 2-adrenoreceptor density and affinity for catecholamines (CA) were examined in 22 patients with essential hypertension (EH) which was resistant to therapy. Lymphocyte beta 2-adrenoreceptor density was 1.5 times more in EH patients than in normotensive donors, but the receptor affinity for CA was the same. Prostaglandin E2 infusions permitted the resistance to antihypertensive therapy be overcome in 17 patients; it was accompanied by a decrease in of lymphocyte beta 2-adrenoreceptor density, receptor's affinity for 1-isoproterenol showed a 7-fold increase. There was no steady antihypertensive effect on prostaglandin E2 infusions in 5 EH patients: in these cases lymphocyte beta 2-adrenoreceptor density increased and their affinity for CA decreased.

Beta 2-adrenergic receptor density and platelet adenylate cyclase activity were determined in the peripheral blood of healthy donors during short-term physical exercise and compared to changes in biochemical parameters. The data obtained indicate the activation of sympathetic-adrenal system in general and suggest phasic regulation of catecholamine beta-adrenergic receptors.