The influence of smoking on the functional state of microcirculation according to laser doppler flowmetry and clinical anamnestic data of patients with arterial hypertension

Background. Detailed study of the functional state of microcirculation in combination of arterial hypertension and tobacco smoking, as the most common and prognostically important risk factors for atherogenesis, will not only clarify pathogenetic effect of tobacco smoke on the terminal vascular bed, but also outline directions of active counteraction to it.Purpose. To study the effect of TS on the functional state of SM using laser Doppler flowmetry in patients with AH.Methods. 185 patients with stage 1,2 AH involved in the study were divided into 2 equivalent groups according to main clinical and laboratory data: group 1 – non-smokers (n = 134, mean age was 57.0 [50.0; 60.0]), group 2 – patients who smoke 1–1.5 packs of cigarettes per day (n = 51, mean age was 54.0 [48.0; 58.0]). Patients were prescribed short-acting antihypertensives drugs, which were used whenever required 5 days before the study. SM was investigated by laser Doppler flowmetry using occlusion test and amplitude-frequency spectrum analysis of hemoperfusion fluctuations.Results. Obtained data showed negative acute effect of ingredients of tobacco smoke on almost all structural elements of microhemocirculation. Revealed deviations are characterized by constriction of precapillary segment of microvascular bed with increase in myogenic tone and equal 3.1 units [2.6; 4.1] versus 2.3 units [1.7; 3.4] in the alternative group (p = 0.007), decrease in capillary blood flow from 4.5 units [3.5; 5.8] compared with the group of non-smokers – 5.2 units [4.0; 7.3] (p = 0.041), statistically significant intensification of arteriolar-venular blood flow with formation of venous congestion, limitation of dilated reserve of microcirculation.Conclusion. Tobacco smoking leads to significant microcirculation disorders that are projected onto changes in terminal vascular bed, inherent with AH, which significantly reduces the functional state of microcirculation, limits its reserve potential and promotes the development of tissue ischemia.

The terminal vascular bed in the superficial cortex of the rat

✓ The capillaries in the vascular bed of the rat brain have been investigated by means of scanning electron microscopy of corrosion casts. A technique is described that allowed the finer ramifications to be observed. A series of representative sites from the arteriovenous terminal pathway are described in detail. Contrary to previous reports, the dichotomic pattern of vessel distribution is shown to prevail over the network pattern. Arteriovenous shunts of discrete size were not seen.“Thoroughfare channels” could be recognized. The findings are considered in light of current physiological knowledge, and their significance for microcerebrovascular flow is indicated.

Vascular Diseases are Essentially a Matter of Haemorheology and of Haemostaseology

Vascular diseases have, in different segments of the vascular tree, a different morphology. There is an arteriosclerosis but not an obliterating arteriosclerosis of thoracic and of proximal abdominal aorta. The obliterating arteriosclerosis exists in the branches and in the continuation of these vessels up to the small arteries. Changes similar to arteriosclerosis don't exist either in the terminal vascular bed nor in veins. The material and structure of obliterations is differently composed in different segments of vessels. All those differences are essentially caused by the different local conditions of haemorheology and haemostaseology. A very important point is - the aggregation and adhesion of platelets is posi tively correlated with the shear rate, whereas the activation of the plasmatic coagulation and the development of aggregates of erythrocytes is negatively correlated with the shear rate. The consequences of this for the different vascular segments are fully discussed in the lecture.