Blood Flow Structuring and Its Alterations in Capillaries of the Cerebral Cortex

Mchedlishvili, G. I.; Varazashvili, Manana; Mamaladze, Akaki; Momtselidze, Nana

doi:10.1006/mvre.1997.2012

Cited by 17 publications

(17 citation statements)

References 8 publications

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“…Nevertheless, a very thin blood plasma layer is always preserved during flow between the outer membranes of the RBCs and the luminal membranes of the endothelial cells. The width of such plasma layer was found to be about 0.1 m in the cerebral cortex of rabbits [3,23].…”

Section: Axial Rbcs Flow and Parietal Plasma Layermentioning

confidence: 90%

“…This was identified as the RBCs axial migration or their axial accumulation [32,35]. A thin plasma layer is always in evidence at the microvessel walls, even in the narrowest capillaries, whose lumina are significantly smaller than the diameters of RBCs advancing in the microvessel lumina in a significantly deformed, elongated state [3,7,11,23,36] (Fig. 1).…”

Section: Velocity Profile In Microvesselsmentioning

confidence: 99%

“…It is also a topic for further biorheological research directed to find the background of actual physiopathological phenomena in the microcirculation. [Japanese Journal of Physiology, 51,[19][20][21][22][23][24][25][26][27][28][29][30]2001] This insight of blood flow structuring related to RBCs flow originated in the early 1950s when one of the present authors microscopically investigated the development of local blood stases in living microvessels of transparent tissues of amphibians and warmblooded animals [4]. After a local application of an NaCl crystal of microscopic size on the tissue, near a capillary, the blood flow immediately slowed to a full stop, though the microvascular lumina along the microvessels with stasis did not narrow and the blood flow remained undisturbed in nearby microvessels.…”

Section: Introductionmentioning

confidence: 99%

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Blood Flow Structure Related to Red Cell Flow: Determinant of Blood Fluidity in Narrow Microvessels

Mchedlishvili

Maeda²

2001

Jpn.J.Physiol

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113

104

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Blood advancing in living capillaries (5 to 10 m in diameter) and in the adjoining arterioles and venules (10 to 25 m in diameter) itself represents a specific substance hardly comparable with fluids in a usual understanding of this term. Its greatest part comprises the deformed red blood cells (RBCs) whose size is similar to luminal diameters of the microvessels. The RBCs (comprising great majority of the forming elements in microvessels) are disposed in the normal flow not chaotically, but in a certain order that was identified therefore as "blood flow structure (or structuring) in microvessels" [1][2][3].The specific regime of the RBCs flow in blood vessels changes from larger to smaller luminal diameters. Thus in vessels larger than 0.2 mm, the blood flow can be treated as a homogenous suspension with little error. By contrast, in arterioles or venules smaller than 25 m, and especially in capillaries (whose diameters are smaller than 8 m in humans), the RBCs are not uniformly dispersed, especially because of the presence of a parietal plasma layer containing no cells; thus the blood flow is specifically structured (Fig. 1). Disorders of this kind inevitably lead to the disturbance of normal blood rheological properties in the microvessels.Japanese Journal of Physiology Vol. 51, No. 1, 2001 19Japanese Journal of Physiology, 51, 19-30, 2001 Key words: RBC axial flow, parietal plasma layer, RBC aggregation, RBC deformation, plasma viscosity. Abstract:The review article deals with phenomena of the blood flow structure (structuring) in narrow microvessels-capillaries and the adjacent arterioles and venules. It is particularly focused on the flow behavior of red blood cells (RBCs), namely, on their specific arrangements of mutual interaction while forming definite patterns of self-organized microvascular flow. The principal features of the blood flow structure in microvessels, including capillaries, include axial RBC flow and parietal plasma layer, velocity profile in larger microvessels, plug (or bolus) flow in narrow capillaries, and deformation and specific behavior of the RBCs in the flow. The actual blood flow structuring in microvessels seems to be a most significant factor in the development of pathological conditions, including arterial hypertension, brain and cardiac infarctions, inflammation, and many others. The blood flow structuring might become a basic concept in determining the blood rheological properties and disorders in the narrow microvessels. No solid theoretical (biorheological) basis of the blood flow structuring in microvessel has been found, but in the future it might become a foundation for a better understanding of the mechanisms of these properties under normal and pathological conditions in the narrowest microvessels 5 to 25 m large. It is also a topic for further biorheological research directed to find the background of actual physiopathological phenomena in the microcirculation.

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Section: Axial Rbcs Flow and Parietal Plasma Layermentioning

confidence: 90%

Section: Velocity Profile In Microvesselsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Blood Flow Structure Related to Red Cell Flow: Determinant of Blood Fluidity in Narrow Microvessels

Mchedlishvili

Maeda²

2001

Jpn.J.Physiol

Self Cite

113

104

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“…Moreover, in the ischemic regions of the brain, the occurrence of plasma flow without erythrocytes through the cerebral capillary vessels is already increased [25]. HBO may overcome this drawback of triple-H therapy by increasing the quantity of oxygen physically dissolved in the plasma.…”

Section: Clinical Hbo Treatment Of Neurological Impairment and Cerebrmentioning

confidence: 99%

Hyperbaric Oxygen for Cerebral Vasospasm and Brain Injury Following Subarachnoid Hemorrhage

Ostrowski

Zhang

2011

Transl. Stroke Res.

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The impact of acute brain injury and delayed neurological deficits due to cerebral vasospasm (CVS) are major determinants of outcomes after subarachnoid hemorrhage (SAH). Although hyperbaric oxygen (HBO) had been used to treat patients with SAH, the supporting evidence and underlying mechanisms have not been systematically reviewed. In the present paper, the overview of studies of HBO for cerebral vasospasm is followed by a discussion of HBO molecular mechanisms involved in the protection against SAH-induced brain injury and even, as hypothesized, in attenuating vascular spasm alone. Faced with the paucity of information as to what degree HBO is capable of antagonizing vasospasm after SAH, the authors postulate that the major beneficial effects of HBO in SAH include a reduction of acute brain injury and combating brain damage caused by CVS. Consequently, authors reviewed the effects of HBO on SAH-induced hypoxic signaling and other mechanisms of neurovascular injury. Moreover, authors hypothesize that HBO administered after SAH may “precondition” the brain against the detrimental sequelae of vasospasm. In conclusion, the existing evidence speaks in favor of administering HBO in both acute and delayed phase after SAH; however, further studies are needed to understand the underlying mechanisms and to establish the optimal regimen of treatment.

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“…Parietal cerebral cortex was fixated in situ simultaneously by way of an abrupt drop of the systemic arterial pressure (dissection of thoracic portion of the ligated common carotid artery) both under control conditions and within 60-90 minutes after dextran administration (10). This was performed by directly applying to the brain surface a piece of cotton which had been abundantly soaked in 20% formaldehyde dissolved in 96% ethanol.…”

Section: Rabbit Experiments With Cerebral Cortex (N = 10)mentioning

confidence: 99%

Microcirculatory Stasis Induced by Hemorheological Disorders: Further Evidence

MCHEDLISHVILI¹,

GOBEJISHVILI²,

MAMALADZE³

et al. 1999

Microcirculation

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Objective: Reinvestigate the microcirculatory alterations immediately responsible for blood rheological disorders and blood stases, which are related to red blood cell (RBC) aggregation in capillaries. Methods: Blood rheological disorders were produced by significantly intensified intravascular red blood cell aggregation in the intestinal mesentery of Wistar rats and in the cerebral cortex of Chinchilla rabbits, either systemically (by intravascular administration of high molecular-weight dextran) or locally (by increase of high-molecular compounds in blood plasma inside individual or groups of capillaries). Results: Under conditions where the microvascular lumina were not decreased and the arteriolovenular pressure gradients got even higher, the significantly enhanced intravascular RBC aggregation resulted in the slowing down of blood flow in the microvessels to a full stop. Conclusion: A significant increase in microvascular RBC aggregation results in local hemorheological disorders, which is, in all probability, related to derangement of the blood-flow structuring in microvessels. KEY WORDS: microcirculation, blood rheological disorders, intensified erythrocyte aggregation, blood-flow structuring in microvessels

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Blood Flow Structuring and Its Alterations in Capillaries of the Cerebral Cortex

Cited by 17 publications

References 8 publications

Blood Flow Structure Related to Red Cell Flow: Determinant of Blood Fluidity in Narrow Microvessels

Blood Flow Structure Related to Red Cell Flow: Determinant of Blood Fluidity in Narrow Microvessels

Hyperbaric Oxygen for Cerebral Vasospasm and Brain Injury Following Subarachnoid Hemorrhage

Microcirculatory Stasis Induced by Hemorheological Disorders: Further Evidence

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