Laser light scattered from tissue in vivo is broadened in line width as a result of the Doppler shift produced by moving red cells in the microcirculation. A feasibility study was carried out to demonstrate use of this effect to measure and monitor tissue blood flow. Light from a helium-neon laser illuminated a 1-mm area of tissue (human skin or rat renal cortex), and the backscattered light was detected with a photomultiplier. The spectrum of the Doppler beat notes was analyzed directly with a digital spectrum analyzer, or processed by analog circuitry to yield a flow parameter based on the root-mean-square Doppler line width. This parameter was compared with 133Xe washout in the skin of volunteers subjected to UV-induced erythema and the skin of volunteers subjected to UV-induced erythema and was found to vary in an approximately linear manner with skin blood flow. The laser instrument provided continuous monitoring of blood flow fluctuations, including the pulsatile component. The instrument was used to monitor flow in the outer cortex of the rat kidney during administration of norepinephrine, angiotensin, hydralazine, dextran, dopamine, nitroprusside, and angiotensin blocked by saralasin. Dynamic and steady-state responses were consistent with known pharmacology and renal physiology, and with the assumption that vasoconstrictor angiotensin II receptors in the kidney are accessible to blood-borne inhibitors. The laser-Doppler method is a promising tool for rapid monitoring of dynamic changes in tissue perfusion.
stiffness and pulse wave velocity / Aorta and carotid arteries 137 (0.94 to 1.01) p = 0.096; Obesity OR = 0.47 (0.29 to 1.77) p = 0.003 and Diabetes OR = 2.41 (1.15 -5.05) p = 0.020. Conclusions: According to the results obtained, genetic polymorphisms variables were not in the multivariate analysis equation to determine the increase of the PWV, which can be explained either by being included in the selected variables such as hypertension, or on the other hand, they may not have enough strength to remain in the equation. So, according to this study, PWV has much more to do with behaviors and traditional risk factors than the genetic heritage.P883 Endothelial dysfunction, pulse wave velocity and augmentation index are correlated in subjects with systemic arterial hypertension?
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