Red cell separation in the mesenteric capillary network

Transvascular and intravascular fluid transport in the rainbow trout:revisiting Starling's forces, the secondary circulation and interstitial compliance

“…The actual Hctmic in fish is unknown. If we assume it is between 8 and 12, which seems reasonable based on mammalian studies (Johnson, 1971), then between half and two-thirds of the volume lost from the macrocirculation during 35% hemorrhage can be nearly instantaneously replaced by elastic recoil of the microcirculation. This is of obvious benefit in maintaining central venous pressure and it provides a safety factor until volume can be restored from the interstitium.…”

“…Plasma storage or mobilization from an intravascular compartment (whose hematocrit is lower than systemic hematocrit) in response to volume expansion or depletion, respectively, appears to be the most likely scenario, and it has a precedent in mammalian studies. It is well known that in mammals the hematocrit in capillary-size vessels is considerably less than that in large vessels (Johnson, 1971), and that the ratio of the hematocrit in the whole cardiovascular system to hematocrit in large systemic vessels (Hct w/Hctsys), also called the Fcell ratio, is approximately 0.9 (Albert, 1971). In a recent review, Lee (2000) defined the mammalian microcirculation as all vessels with a diameter smaller than 250 µm, i.e.…”

Technical report—a new chamber technique for microvascular studies in unanesthetized hamsters

“…To relate these findings to systemic pressures, most of the experiments have been carried out with the animal anesthetized [3,8,10,14,15,18], hence adding additional (undesired) effects to the phenomenon under study. In unanesthetized, small animals transparent chambers were used for observation of microcirculation and surrounding tissue.…”

“…Specialized video processors (video photometric analyzer + cross correlation computation) provide directly, and on-line [12], analogous data proportional to the intensity of light in a selected area whose position and size can be controlled manually within a televised scene. Positioning two of these windows along a given capillary provides a means of implementing the so-called dual slit technique [12,14] with the further advantage that it becomes possible to study simultaneously every blood vessel seen within a given field when the data is recorded on video tape. At present, the velocities that can be reliably measured by this technique range from 0 to 2.5 mm/s for European TV-standards.…”

Microfluidic Platforms for the Interrogation of Intravascular Cellular Trafficking Mechanisms Influenced by Hemodynamic Forces

“…Early intravital microscopy studies observed marked heterogeneity of hematocrit in the microvasculature with a mean hematocrit far less than systemic hematocrit [ 29 ]. Although fabrication of truly microfl uidic devices was not yet possible, scientists created scaled models of the microvasculature in which to investigate erythrocyte partitioning.…”