[The chronotropic reaction and the dynamics of the blood supply to the forearm during modulation of the baroreceptor reflex activity in patients with arterial hypertension]. / Khronotropnaia reaktsiia i dinamika krovosnabzheniia predplech'ia pri moduliatsii aktivnosti baroretseptornogo refleksa u bol'nykh s arterial'noi gipertenziei.

Original method of baroreflex activation and deactivation was described. Bradycardia and vasodilatation of the forearm vessels were observed at baroreflex activation. Tachycardia and forearm blood flow reduction were observed at baroreflex deactivation. The sensitivity of baroreflex heart component vas shown to depend upon the arterial pressure and a baseline cardiac cycle duration in both normo- and hypertensive subjects.

Serum kynurenine and neopterin concentrations in patients with cardiomyopathy.

Serum kynurenine and neopterin concentrations were determined in patients with hypertrophic (n = 22) and dilated (n = 23) cardiomyopathy. Significantly increased kynurenine and neopterin levels have been observed in cases of dilated cardiomyopathy. In these patients we found a positive correlation between serum kynurenine and neopterin levels (RS = 0.52, P less than 0.001). There existed several associations between the laboratory parameters neopterin and kynurenine and clinical findings, such as left ventricle (LV) systolic volume and LV circumferential fiber shortening velocity in patients with dilated cardiomyopathy (all P less than 0.05). In vitro, interferon-gamma induces the formation of neopterin in human monocytes/macrophages. Also the degradation of tryptophan via the kynurenine pathway is induced by interferon-gamma. Our data show that increased kynurenine as well as neopterin accumulation in serum are associated with severity of dilated cardiomyopathy. Thus, the data point to a role of immune activation in the pathogenesis of the disease.

Haemodynamic resistance of forearm vessels during prolonged drug treatment of essential hypertension.

In 40 patients with essential hypertension, the authors studied the haemodynamic resistance in forearm vessels before and after 15-min arterial occlusion, and changes in this parameter during a three-year combined antihypertensive treatment. The study revealed that the 15-min occlusion did not entirely suppress the contractile activity of vascular smooth muscles. Under these conditions, the minimum vascular resistance reflects the sum of structural and functional alterations. The character of change in minimal haemodynamic vascular resistance depends on the mechanism of action of the antihypertensive drugs. Administration of the post-synaptic alpha-adrenergic blocker Pratsiol produces a decrease in the minimal haemodynamic vascular resistance.