Learn More
As arterialized blood transits from the central circulation to the periphery, oxygen exits through the vessel walls driven by radial oxygen gradients that extend from the red blood cell column, through the plasma, the vessel wall, and the parenchymal tissue. This exit determines a longitudinal gradient of blood oxygen saturation whose extent is inversely(More)
Preoperative intentional hemodilution is induced by isovolemic exchange of whole blood with colloid solutions in order to gain autologous blood while maintaining normovolemia. The basic mechanism that compensates for the fall of oxygen capacity of the diluted blood is the rise in cardiac output, and organ blood flow, factors that result from the improved(More)
One of the most important functions of the blood circulation is O2 delivery to the tissue. This process occurs primarily in microvessels that also regulate blood flow and are the site of many metabolic processes that require O2. We measured the intraluminal and perivascular pO2 in rat mesenteric arterioles in vivo by using noninvasive phosphorescence(More)
The diameter of the arterial and arteriolar blood vessels was measured as a function of time in the hamster skin fold window preparation. When the animals recovered from the surgical implantation, the diameters of the arterial microvessels exhibited a continuous rhythmic activity throughout the preparation for a period of 2 wk while the chamber was intact.(More)
The effect of cyclic blood flow velocity on local tissue oxygenation was studied by means of a mathematical simulation in the situation where red blood cells (RBC) act as discrete oxygen sources. Cyclic time varying fluctuations of capillary blood (flowmotion) are due to arteriolar vasomotion. This effect was introduced into the model as an oscillating RBC(More)
The role of nitric oxide (NO) in the genesis of cerebral malaria is controversial. Most investigators propose that the unfortunate consequence of the high concentrations of NO produced to kill the parasite is the development of cerebral malaria. Here we have tested this high NO bioavailability hypothesis in the setting of experimental cerebral malaria(More)
Understanding of oxygen delivery by the microcirculation has been dominated by the unitary component analysis of Krogh and Erlangen focussed on oxygen transport mediated by single capillaries, oxygenation of tissue as a whole being extrapolated from findings on oxygen exchange in these vessels. This analysis is under revision since capillaries are not sole(More)
Intravital microscopy and laser Doppler fluxmetry (LDF) were used to assess vasomotion and flux motion in skeletal muscle microcirculation. To clarify the relation between vessel type and LDF signals, arterioles, capillaries, and venules were sequentially studied. We used as an experimental model the hamster skin fold window preparation to record vasomotion(More)
The effect of molecular dimension of hemoglobin (Hb)-based O(2) carriers on the diameter of resistance arteries (A(0), 158 +/- 21 microm) and arterial blood pressure were studied in the conscious hamster dorsal skinfold model. Cross-linked Hb (XLHb), polyethylene glycol (PEG)-conjugated Hb, hydroxyethylstarch-conjugated XLHb, polymerized XLHb, and(More)