[The baroreceptor reflex as a predictor of crises in arterial hypertension]. / Sostoianie baroretseptornogo refleksa kak prediktor krizovogo techeniia arterial'noi gipertonii.

The sensitivity of baroreceptor reflex was determined by the "neck chamber" method at a pressure of 40 mm Hg in patients with mild, moderate and malignant arterial hypertension (AH). A 24-hour blood monitoring was performed in patients with mild and moderate AH. There was a negative correlation between the lowering values in blood pressure on baroreceptor stimulation and the incidence of hypertensive crises in all the groups. There was also a negative correlation between the baroreceptor sensitivity and the daily blood pressure variations in patients with moderate AH. The findings suggest that a decrease in baroreceptor sensitivity might be a predictor of the critical course of AH.

[Immunological effects of captopril and ramipril in patients with hypertension]. / Immunologicheskii éffekt kaptoprila i ramiprila u bol'nykh gipertonicheskoi bolezn'iu.

Fifteen patients with essential hypertension underwent treatment with captopril (7 patients) and ramipril (8 patients). The drugs belong to angiotensin-converting enzyme (ACE) inhibitors. Pretreatment immunological examination and that after a 10-15-week course of the above therapy involved measurements of IgG, IgA, IgE and beta 2-microglobulin. The analysis of the trend in the immunological indices demonstrated that captopril, distinct from ramipril by the presence of a sulfhydryl group, caused a decrease in immunological parameters suggesting a potential role of culfhydryl groups in mediating ACE inhibitor action on the immune system. The immunological properties of captopril may appear useful in various systemic diseases.

[Baroreceptor regulation of blood circulation in healthy persons and in patients with hypertension]. / Baroretseptornaia reguliatsiia krovoobrashcheniia u zdorovykh lits i bol'nykh gipertonicheskoi bolezn'iu.

Carotid sinus baroreceptor stimulation by generating subatmospheric pressure in a special neck chamber was used to examine the hemodynamic baroregulation in males divided into 4 groups: (1) healthy subjects; (2) patients with Stages IB to IIA hypertensive disease; (3) those with Stage IIB hypertension; (4) those with malignant hypertension. In Group 2, the patients had a lower ability of carotid baroreflexes to damp elevated systolic pressure whereas in Group 3 there was baroreflex readjustment and effective vasomotor control was increased, which appeared as more pronounced lowering of blood pressure elevations. The patients with malignant hypertension showed a decreased effective baroreflex control of circulation, which might be one of the factors causing that course of the disease.

[Reaction of the skin microvessels to a change in blood flow to the extremities based on data from photoplethysmography and laser Doppler fluxmetry]. / Reaktsii mikrososudov kozhi na izmenenie krotoka v konechnosti po dannym fotopletizmografii i lazernoi doppler-fluksometrii.

A comparative study of the non-invasive methods of photoplethysmography and laser Doppler fluxmetry in the assessment of dermal vascular responses of the forearm has been made. Vasoconstrictive and vasodilatation responses on intracutaneous introduction of noradrenaline in a dose of 10(-6) g have been quantitatively assessed. Correlation volumes of vascular responses in the use of these methods have been obtained.

[Hypotensive and hemodynamic effects of guanfacine in arterial hypertension]. / Gipotenzivnyi i gemodinamicheskie effekty guanfatsina pri arterial'noi gipertonii.

The therapeutic efficacy of guanfacine was investigated in a group of 32 hypertensive patients. Guanfacine caused a marked decrease in total peripheral vascular resistance (by 19.8%, p less than 0.001) and, hence, in blood pressure (by 19.4%), p less than 0.001). A slight reduction in the heart rate (by 9.8%, p less than 0.01) was compensated by an increase in stroke volume (by 11.8%, p less than 0.05) so that cardiac output remained constant or was even slightly raised. After 4 weeks of treatment there was a regression of the left ventricular wall thickness and mass (by 7.43 +/- 2.44 g, p less than 0.05). Guanfacine monotherapy was effective in 75% of patients with moderate hypertension (using low doses 1-3 mg/day). In severe hypertensive disease a satisfactory therapeutic response was mostly achieved by a combination of Guanfacine (3-5 mg/day) with a beta-blocker, diuretic or vasodilator. Guanfacine is a promising agent in the long-term treatment of stable hypertension, particularly in patients, whom diuretics or beta-blockers are contraindicated.

[Hemodynamic effects of mesotrin after its intravenous administration]. / Gemodinamicheskie éffekty mezotrina pri vnutrivennom vvedenii.

Mesotrin, a novel Soviet calcium antagonist, given in a single intravenous dose was evaluated for effects on central and peripheral hemodynamic parameters in 27 patients who had no clinical signs of acute or congestive heart failure. The drug used in an antiarrhythmic doses resulted in a substantial decrease in stroke index and cardiac index and increase in total peripheral vascular resistance virtually only by enhancing resistive vascular tone. Mesotrin showed no significant effects on the venous segment of the vascular bed. To attenuate the negative action of the drug on myocardial contractility it was proposed to give it in combination with calcium gluconicum which practically completely abolished the adverse hemodynamic effects of mesotrin.

[The vasodilator minoxidil in the treatment of hypertension]. / Vazodilatator minoksidil v lechenii gipertonicheskoi bolezni.

A new vasodilating agent, minoxidil, was used in 17 patients with essential hypertension that had not responded sufficiently to combined treatment with 3 or 4 conventional hypotensive agents. After minoxidil was added, mean arterial BP dropped by 50 +/- 2.4 mmHg, the effect persisting for 3-4 months. Discontinuation of minoxidil after a short-term administration of 20 +/- 3.8 mg daily was accompanied with a BP rise eventually reaching baseline values, while gradual replacement with nifedipine after daily doses of minoxidil had been reduced smoothly over 3 or 4 weeks allowed to maintain mean arterial BP about 34 +/- 1.8 mm Hg below the baseline. The use of minoxidil in combination with beta-blockers and diuretics for 6 weeks resulted in a significant increase of left-ventricular myocardial weight, while cardiac contractility and pump function remained intact, as evidenced by electrocardiography. After 3 weeks of treatment, peripheral vascular resistance diminished in the forearm owing to reduced arterial and arteriolar tone, yet no reverse development of the vascular-wall adaptive structural changes could be seen at venous occlusion plethysmography.

[Use of prostenon in the treatment of severe and malignant forms of hypertension]. / Primenenie prostenona dlia lecheniia tiazhelykh i zlokachestvennykh form arterial'noi gipertonii.

Forty-five patients with high arterial hypertension (AH) refractory to hypotensive therapy were treated with 3 or 4 prostaglandin E2 (PGE2) infusions (Prostenon). Twenty-two of those had the malignant AH syndrome. The hypotensive effect of prostenon was most pronounced in patients with essential hypertension, less marked in those with chronic glomerulonephritis and pyelonephritis and virtually nonexistent in cases of renovascular hypertension. It persisted until the discharge in most patients, and for several months in some. In severe AH, prostenon improved blood supply to the brain, kidneys and, less notably, the limbs, normalized venous dilatability and the cardiac index, brought down total peripheral resistance, particularly in cases where pretreatment values had been high, reduced platelet aggregation 1.8-fold, and contributed to reverse development of eyeground changes in some patients with malignant AH syndrome.

[Venous distensibility in essential hypertension]. / Izuchenie rastiazhimosti ven u bol'nykh gipertonicheskoi bolezn'iu.

Using venous occlusive plethysmography, venous distensibility was examined in 85 hypertensive patients and in 21 normal men. Venous distensibility in the hypertensive versus normal subjects was significantly lower, being inversely depended on the blood pressure level. Venous distensibility depended directly on the blood flow in the forearm and inversely on the resistance of the resistive vessels at rest. This may indicate that the reduction of venous distensibility was caused by both functional and structural changes characteristic of both resistive and capacitance vessels. It appears that functional and structural alterations in the system of low pressure, along with an elevated resistance of the arterioles, were actively involved in changes of the peripheral resistance and the development of a hypertensive state.

[Therapeutic value of pratsiol and its effect on indicators of central and peripheral hemodynamics in patients with hypertension]. / Lechebnyi effekt pratsiola i ego vliianie na pokazateli tsentral'noi i perifericheskoi gemodinamiki u bol'nykh gipertonicheskoi bolezn'iu.

Thirty-eight patients with stage IIB essential hypertension have been studied to determine the therapeutic activity of prazosine (pratsiol, "Orion" company, Finland) and its influence on the parameters of the central and peripheral hemodynamics. It has been established that following the oral administration of the drug, a hypotensive effect develops in 90-120 min and lasts for about six h. After a three-week course of treatment, the arterial pressure in the majority of patients decreased due to a reduction in the total peripheral resistance and the tone of the resistant vessels (arterioles). Simultaneously, there was an increase in the heart rate, end diastolic and stroke volumes and in the cardiac output. In a smaller portion of patients, the arterial pressure decreased due to the predominant reduction in the venous tone; the elasticity of the veins increased sharply, the end diastolic stroke and minute volumes diminished. The heart rate and total peripheral resistance showed no statistically significant changes. It has been established that pratsiol acts as an arterial and venous vasodilator and that it is advisable to use the drug in combination with beta-blockers and diuretics.

[Mechanism of the increase in peripheral vascular resistance in hypertension]. / O mekhanizme povysheniia perifericheskogo soprotivleniia sosudov pri gipertonicheskoi bolezni.

To elucidate the mechanisms determining peripheral vascular resistance in arterial hypertension the circulation in the leg was studied by venous occlusion plethysmography in 41 hypertensive patients and 11 normotensive controls. It was found that vascular resistance in the leg both at rest and during maximal vasodilatation were within the normal limits in labile and mild hypertension, but it was significantly raised in established, malignant and refractory hypertension. The increased Rmin strongly suggests structurally narrowed lumina, but not enhanced vasoconstriction of the neurohumoral origin. Moreover, vascular smooth muscle activity at rest was not increased in absolute values in hypertensive patients though it may be considered as inappropriately "high" in relation to the altered vascular design. It was concluded, that at least in the vascular bed of the leg a rise in peripheral resistance is caused by structural changes of the resistance vessels along with unchanged contractile activity of the vascular smooth muscles.