[Structural-functional characteristics of cervical vessels in hypertensive patients under changed atmospheric pressure].

The ultrasonic location technique was used to measure intima-media thickness (IMT), as well as internal systolic diameter of and linear blood velocity in the cervical arteries in people with initial hypertension. Correlation analysis elicited a temporal contingency between these parameters and daily average values of atmospheric pressure. Thus, common carotid artery IMT tended to increase on high-pressure days. Besides, diameters of the common and internal carotid arteries, and vertebral artery were narrowed and, consequently, linear blood velocity in these vessels increased. This relationship is more evident in men than women and in elderly subjects than young. These results are suggestive of a vasoconstrictive action of high atmospheric pressure on these arteries. The relationship is not universal, as it is nonlinear for diameter of the internal carotid artery and inverse for the external one. This implies different sensitivity of arteries to the factor under study and possible blood redistribution in the arterial basin depending on external pressure. The relationship was observed equally on the day of investigation and previous days, which points to its temporal stability.

[Solar phase effect on elasticity of the brachial artery and blood flow in humans].

Single and double examinations of normal males and females in the course of 11-year solar cycle with the use of oscillovasometry and occlusive plethysmography established a direct correlation between the effective diastolic radius of the brachial artery and solar activity characteristics on the day of examination, i.e. number of solar spots and intensity of radiation with the 10.7 cm wavelength. Other blood flow parameters demonstrated opposite correlations with the factors in males and females. As solar activity increased, females displayed linear decrements of arterial elasticity and regional peripheral resistance and growth of the volumetric blood flow velocity equally at rest and at the peak of post-occlusion reactive hyperemia. In males, the correlations had the reversed sign. Besides, males were noted to reduce venous reserve and venous outflow from antebrachial muscles proportionally to the increase of Wolf number. It is inferred that elevated solar activity may be responsible for impairment of the feeling of well-being of people with reduced cardiovascular reserve, particularly in space tight or at high altitudes in the absence of or under weak protection of the geomagnetic field and ozone layer.