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Biomedical subjects

V V Orlov

Publications and source records attributed to V V Orlov.

17 recordsLinked to original sources
PubMed1987

[Effect of the sympathetic nervous system on local physical and chemical mechanisms of regulating circulation in skeletal muscles].

In healthy subjects and in patients with beginning hypertension the blood flow in the forearm muscles was studied in resting as well as in hyperemia induced with excitation of the sympathetic nervous system. The blood flow and the hyperemia proved to be considerably smaller in the patients whereas the blood flow in mental stress was much greater in them as compared to healthy subjects. In emotional stress, the hyperemia considerably decreased in healthy subjects. In maximal vasodilatation induced with cessation of blood flow in limbs, the reflex vasoconstrictory responses were preserved. The data obtained suggest sympathetic influences upon the induced hyperemia and deny the phenomenon of functional sympatholysis.

Blood Pressure↗
PubMed1983

[Changes in blood flow after longitudinal stretching of the cat m. gastrocnemius].

Longitudinal stretch of the cat m. gastrocnemius by 10-30% of initial length increased the passive strength and regularly decreased the blood flow, the latter being dependent not on the degree of deformation but on the value of passive tension. Postelongation hyperemia develops after the stretch. This reaction seems to be similar to hyperemia due to the artery occlusion in the muscle and is considerably weaker than the postcontraction increase in the blood flow. The character of intramuscular mechanical effects on the vessels during both the active contractions and the passive stretch, is discussed.

Animals↗
PubMed1983

[Analysis of systemic hemodynamics in altered hydraulic resistance of the initial portion of the aorta].

The changes of cardio- and hemodynamics on increase of hydraulic resistance in the initial part of aorta under conditions of external occlusion (EO) of the ascending aorta or internal occlusion (IO) of aortic valve opening or of the ascending aorta lumen, were studied in anesthetized cats. Under EO to 50% of square section of the ascending aorta a considerable increase of cardiac output (CO) with small rise of aortic pressure proximal to site of occlusion (AP-1) was observed. Further EO was accompanied by a decrease of CO with a more pronounced rise of AP-1. AP distal to EO kept unchanged within wide range of aorta narrowing. 10 of ascending aorta lumen caused similar correlations of CO, left ventricle systolic pressure (LVP) and AP distal to the occlusion site. Under 10 of aortic valve opening, progressive decrease of CO with simultaneous increase of LVP and lowering of AP takes place. The role of the coronary blood flow as a factor increasing the myocardial contractility under increase of AP and the significance of baroreceptor reflexes, are discussed.

Animals↗
PubMed1982

[Systemic vascular reactions to a decrease in volumetric blood flow velocity during artificial circulation].

In anesthetized cats with artificial circulation, a decrease in the systemic perfusion pressure (SPP) following reduction of the blood flow volume velocity evokes under conditions of weakly pulsating blood flow a constrictory response of neurogenic character which can be compensated for by an opposite myogenic response in conditions of pulsating blood flow. These differences only occur at a high enough initial level of the SPP. The myogenic component of regulation of the resistance vessels tonus seems to be suppressed in conditions of weakly pulsating blood flow. Questions bearing on regulation of the systemic hemodynamics, are discussed.

Animals↗
PubMed1980

[Fluorimetric study of methacycline complex formation with beryllium, aluminum, magnesium, calcium and zinc ions].

Complex formation of metacycline (Pv) with beryllium, aluminium, magnesium, calcium and zinc ions in aqueous solutions was studied fluorometrically. The antibiotic formed the following compounds: CaPv2 (pH 9.45), MgPv (pH 10.40), Be Pv (pH 7.0 and 11), Ca Pv (pH 13.5), Zn Pv (pH 7.15) and Al Pv (pH 6.0). Relationship between the solution fluorescence level and the values of pH, the quantum yield of fluorescence of Pv and the complexes and the kinetics of the reactions of complex formation of Pv with Be and Al were studied. The mechanism of Pv complex formation with the metal ions is discussed. A method for analysis of microgram amounts of Pv in biological fluids was developed. The method is based on the antibiotic fluorescent reaction with magnesium ions.

Aluminum↗
PubMed1978

[Descending vasoconstrictor fibers in the thoracic region of the spinal cord].

Analysis of the arterial pressure responses to electric stimulation of the spinal cord structures at T1 to L3 showed two zones of the maximal pressure activity in the lateral and medial parts of the lateral funiculus. After destruction of the lateral part at T1-T2 level, a decrease in the systemic arterial pressure occurred after stimulation of the pressor zone of the vasomotor center and structures of the spinal cord at the levels of C5 and ischiatic nerve. These and previously obtained data suggest that the pressor responses to stimulation of the lateral part of the lateral funiculus of the spinal cord are of the reticulospinal origin. Participation of the propriospinal fibers in the pressor responses to stimulation of the medial zone of the lateral funiculus is discussed.

Animals↗