Introduction While water was initially considered as a freely diffusible tracer in arterial spin labeling (ASL) perfusion MRI, emerging evidence suggested a limited degree of water exchange between the vascular (capillary) and tissue compartments (1, 2). Quantification of water extraction fraction and permeability is important for accurate perfusion quantification in ASL methods, and may provid...

By means of transillumination (microtransilluminator and light pipe), comparative analyses were carried out on geometry, topography, and morphometry of microcirculation in the cerebral cortex, left atrial muscle, and mesentery of the cat using computer analysis. In addition, specific types of capillary distribution (concurrent, countercurrent, and asymmetric distribution) in these three organs ...

NADH-localized fluorometry was used as a noninvasive technique to monitor changes in the energy state of intact tissue (muscle and connective tissue), without anesthesia, as a function of blood plasma O(2)-carrying capacity in the hamster window chamber model. Acute moderate isovolemic hemodilution was induced by two isovolemic hemodilution steps: in the first step, 6% 70-kDa dextran (Dex70) wa...

ACCORDING to the classical hypothesis of Starling (1896) the exchange of water and small lipid-insoluble molecules across the capillary membrane is largely governed by the balance between hydrostatic and colloid osmotic pressures, the existence of the latter being dependent upon relative impermeability of the capillary membrane to plasma proteins. Starling's concept has been verified by direct ...

Inhibition of carbonic anhydrase (CA) activity (activity in red blood cells and activity available on capillary endothelium) results in decrements in CO2 excretion (VCO2) and plasma-erythrocyte CO2-HCO(-3)-H+ disequilibrium as blood travels around the circulation. To investigate the kinetics of changes in blood PCO2 and pH during progressive CA inhibition, we used our previously detailed mathem...

Chronic heart failure (CHF) disturbs the alveolar-capillary interface and increases the resistance to gas transfer. Alveolar-capillary membrane conductance (D(M)) and capillary blood volume (V(c)) are subcomponents of the lung diffusion capacity. Elevation of the capillary pressure causes alveolar-capillary membrane stress failure (i.e. increase in capillary permeability to water and ions, and ...

in this paper it has been shown that deterioration of the brain cortex capillary system and negative dynamics of cerebral tissue morphology occur under conditions of hypo kinesia. simultaneously, gamma-aminobutyric acid (gaba) and piracetam have been shown to favor the development of vasodilation and prevent further worsening of the cerebral blood supply. during the experiment, it was also esta...

Nowadays, a large number of methods exist for the visualization the vascular system and the arterial blood supply to various organs of the human body. Angiography techniques are used to image the bulk blood flow in the large vessels of the body like arteries and veins and allow the identification of vascular malformations and vascular alterations like stenosis or occlusions. Such diseases are q...