Recent studies are reviewed, concerning the in vivo wall stiffness of arteries and arterioles in healthy humans, and how these properties adapt to iterative increments or sustained reductions in local intravascular pressure. A novel technique was used, by which arterial and arteriolar stiffness were determined as changes in arterial diameter and flow, respectively, during graded increments in distending pressure in the blood vessels of an arm or a leg. Pressure induced increases in diameter and flow were smaller in the lower leg than in the arm, indicating greater stiffness in the arteries/arterioles of the leg. A 5wk period of intermittent intravascular pressure elevations in one arm reduced pressure distension and pressureinduced flow in the brachial artery by about 50%. Conversely, prolonged reduction of arterial/arteriolar pressure in the lower body by 5 wks of sustained horizontal bedrest, induced threefold increases of the pressure-distension and pressureflow responses in a tibial artery. Thus, the wall stiffness of arteries and arterioles are plastic properties that readily adapt to changes in the prevailing local intravascular pressure. The discussion concerns mechanisms underlying changes in local arterial/arteriolar stiffness as well as whether stiffness is altered by changes in myogenic tone and/or wall structure. As regards implications, regulation of local arterial/arteriolar stiffness may facilitate control of arterial pressure in erect posture and conditions of exaggerated intravascular pressure gradients. That increased intravascular pressure leads to increased arteriolar wall stiffness also supports the notion that local pressure loading may constitute a prime mover in the development of vascular changes in hypertension.
F.22 Improvement to existing health/diagnostic methods/procedures
COBISS.SI-ID: 27299623Documentary on the work of the author of this proposal, with an emphasis on the research project "Planetarz habitat simulation", and on the founding of a research laboratory at the Olympic Sport Centre Planica.
F.21 Development of new health/diagnostic methods/procedures
COBISS.SI-ID: 27321127A water perfused suit provides a sinusoidal temperature stimulus to the entire body surface area, or to only an individual body region. Unattended, the temeprature of the suit describes a sinusoid with limits of 10 deg C and 45 deg C. By depressing a switch to change the direction of the temeprature change, and maintain thermal comfort, the result is a damped oscillation describing the limits of thermal comfort for the surface area stimulated.
F.33 Slovenian patent
COBISS.SI-ID: 26274855