Hydraulic conductivity of the endothelial and outer layers of the rabbit aorta

Vargas, Cristiane Borges; Vargas, Fernando F.; Přibyl, J.; Blackshear, Perry L.

doi:10.1152/ajpheart.1979.236.1.h53

Cited by 35 publications

(27 citation statements)

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“…The remaining unknown in Eq. 36 is Darcy's permeability of the arterial wall, and it is estimated to be K p ϭ 1.2 ϫ 10 Ϫ18 m 2 , which agrees well with the literature values of 1.0 Ϫ 2.0 ϫ 10 Ϫ18 m 2 (10,25,31,34,39). Once the permeability of the wall is fixed, the last remaining unknown, L p,nj, is estimated with Eq.…”

Section: H911 Mass Transport Of Ldl With Effects Of Wall Shear Stresssupporting

confidence: 82%

Computational modeling of coupled blood-wall mass transport of LDL: effects of local wall shear stress

Olgaç

Kurtcuoglu²,

Poulikakos³

2008

American Journal of Physiology-Heart and Circulatory Physiology

118

175

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Olgac U, Kurtcuoglu V, Poulikakos D. Computational modeling of coupled blood-wall mass transport of LDL: effects of local wall shear stress. Am J Physiol Heart Circ Physiol 294: H909-H919, 2008. First published December 14, 2007 doi:10.1152/ajpheart.01082.2007.-The work herein represents a novel approach for the modeling of lowdensity lipoprotein (LDL) transport from the artery lumen into the arterial wall, taking into account the effects of local wall shear stress (WSS) on the endothelial cell layer and its pathways of volume and solute flux. We have simulated LDL transport in an axisymmetric representation of a stenosed coronary artery, where the endothelium is represented by a three-pore model that takes into account the contributions of the vesicular pathway, normal junctions, and leaky junctions also employing the local WSS to yield the overall volume and solute flux. The fraction of leaky junctions is calculated as a function of the local WSS based on published experimental data and is used in conjunction with the pore theory to determine the transport properties of this pathway. We have found elevated levels of solute flux at low shear stress regions because of the presence of a larger number of leaky junctions compared with high shear stress regions. Accordingly, we were able to observe high LDL concentrations in the arterial wall in these low shear stress regions despite increased filtration velocity, indicating that the increase in filtration velocity is not sufficient for the convective removal of LDL.low-density lipoprotein transport; lipid accumulation; atherosclerosis; leaky junction MASS TRANSPORT of large molecules such as low-density lipoprotein (LDL) has received considerable interest in recent years because of its significance in the early stages of atherosclerosis. Locally elevated concentrations of LDL in the arterial wall are considered to be the initiator of atherosclerotic plaque formation (20,26). Various experimental (2,19,21,37,38) and computational (1, 13-15, 25, 31, 33, 40) studies have been conducted to comprehend the pathways and mechanisms governing LDL transport from the artery lumen into the arterial wall and within the arterial wall. There are two pathways of LDL transport through the endothelium: by vesicular transcytosis, which is regulated by receptors on the endothelial cells (30), and through leaky junctions, most of which are located at the sites of dying or replicating cells (18,19).Early experimental studies on LDL transport were performed in animals. The main method was systemic injection of LDL solution with subsequent harvesting and examination of the animal's arteries. Lin et al. (19) 2) used endothelial cell cultures to study LDL transport under pressurized conditions and found that LDL transport through leaky junctions constitutes the major part of total LDL transport (90.9%), whereas only a small portion occurs via the vesicular pathway (9.1%). Because the occurrence of leaky junctions is governed by the adjacent endothelial cells, and because the behavior o...

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Section: H911 Mass Transport Of Ldl With Effects Of Wall Shear Stresssupporting

confidence: 82%

Computational modeling of coupled blood-wall mass transport of LDL: effects of local wall shear stress

Olgaç

Kurtcuoglu²,

Poulikakos³

2008

American Journal of Physiology-Heart and Circulatory Physiology

118

175

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“…Ϫ8 cm·s Ϫ1 ·mmHg Ϫ1 at 180 mmHg, slightly lower than our value since the SI may be (only) slightly more compressed(24) at the higher ⌬P*. Using a more primitive measurement technique, Vargas et al (65) found 11.9 ϫ 10 Ϫ8 cm·s Ϫ1 ·mmHg Ϫ1 at 74 mmHg, higher than our value but closer to Tedgui and Lever's 70 mmHg value. At 70 mmHg, the SI is much less compressed, leading to a higher apparent endothelial L p * , than at 100 mmHg (22,24).…”

Section: Parameterscontrasting

confidence: 59%

A theory for water and macromolecular transport in the pulmonary artery wall with a detailed comparison to the aorta

Zeng

Jan

Rumschitzki

2012

American Journal of Physiology-Heart and Circulatory Physiology

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Zeng Z, Jan KM, Rumschitzki DS. A theory for water and macromolecular transport in the pulmonary artery wall with a detailed comparison to the aorta. Am J Physiol Heart Circ Physiol 302: H1683-H1699, 2012. First published December 23, 2011; doi:10.1152/ajpheart.00447.2011The pulmonary artery (PA) wall, which has much higher hydraulic conductivity and albumin void space and approximately one-sixth the normal transmural pressure of systemic arteries (e.g, aorta, carotid arteries), is rarely atherosclerotic, except under pulmonary hypertension. This study constructs a detailed, two-dimensional, wall-structure-based filtration and macromolecular transport model for the PA to investigate differences in prelesion transport processes between the disease-susceptible aorta and the relatively resistant PA. The PA and aorta models are similar in wall structure, but very different in parameter values, many of which have been measured (and therefore modified) since the original aorta model of Huang et al. (23). Both PA and aortic model simulations fit experimental data on transwall LDL concentration profiles and on the growth of isolated endothelial (horseradish peroxidase) tracer spots with circulation time very well. They reveal that lipid entering the aorta attains a much higher intima than media concentration but distributes better between these regions in the PA than aorta and that tracer in both regions contributes to observed tracer spots. Solutions show why both the overall transmural water flow and spot growth rates are similar in these vessels despite very different material transport parameters. Since early lipid accumulation occurs in the subendothelial intima and since (matrix binding) reaction kinetics depend on reactant concentrations, the lower intima lipid concentrations in the PA vs. aorta likely lead to slower accumulation of bound lipid in the PA. These findings may be relevant to understanding the different atherosusceptibilities of these vessels. hydraulic conductivity; low-density lipoprotein cholesterol IN HUMANS, DIFFERENT VESSELS have very different proclivities to develop atherosclerotic lesions. Arteries with thick walls and high lumen pressures, such as the aorta, coronary, and carotid arteries, are by far the most likely to develop atherosclerosis (39, 69). In contrast, the pulmonary artery (PA), a lower pressure, intermediate thickness artery, is normally lesion-free, except under pulmonary hypertension (PH) (13,19). Compelling evidence argues that atherogenic, plasma-derived lowdensity lipoprotein (LDL) cholesterol transport and accumulation in the artery wall, particularly in its subendothelial intima (SI), are fundamental initiating events of early atherosclerotic lesions (13, 50). High SI LDL concentrations appear to lead to LDL binding to the SI extracellular matrix (ECM) to form lipid packets, called liposomes, containing lipid from one or many LDL particles. This LDL binding and modification precede monocyte diapedesis and foam cell formation in lesion-prone aortic areas (41,47). This st...

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“…Vargas et al (42) maintained the rabbit aorta's cylindrical shape and used a weighing method to measure the transmural flow rate. Tedgui and Lever (38) calculated the transmural flow at 70 and 180 mmHg on the same vessel by measuring the velocity of an air bubble in a horizontal catheter connecting the pressurized water source to the rabbit's isolated vessel lumen.…”

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confidence: 99%

Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia

Shou

Jan²,

Rumschitzki³

2006

American Journal of Physiology-Heart and Circulatory Physiology

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Shou, Yixin, Kung-ming Jan, and David S. Rumschitzki. Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia. Am J Physiol Heart Circ Physiol 291: H2758 -H2771, 2006. First published May 26, 2006 doi:10.1152/ajpheart.00610.2005In this study, filtration flows through the walls of the rat aorta, pulmonary artery (PA), and inferior vena cava (IVC), vessels with very different susceptibilities to atherosclerosis, were measured as a function of transmural pressure (⌬P), with intact and denuded endothelium on the same vessel. Aortic hydraulic conductivity (L p) is high at 60 mmHg, drops ϳ40% by 100 mmHg, and is pressure independent to 140 mmHg. The trends are similar in the PA and IVC, dropping 42% from 10 to 40 mmHg and flat to 100 mmHg (PA) and dropping 33% from 10 to 20 mmHg and essentially flat to 60 mmHg (IVC). Removal of the endothelium renders L p(⌬P) flat: it increases Lp of the aorta by ϳ75%, doubles L p of the PA, and quadruples Lp of the IVC. Specific resistance (1/L p) of the aortic endothelium is ϳ47% of total resistance; i.e., the endothelium accounts for ϳ47% of the ⌬P drop at 100 mmHg. The PA value is 55% at Ͼ40 mmHg, and the IVC value is 23% at 10 mmHg. L p of the intact aorta, PA, and IVC are order 10 Ϫ8 , 10 Ϫ7 , and 5 ϫ 10 Ϫ7 cm⅐s Ϫ1 ⅐mmHg Ϫ1, and wall thicknesses are 145.8 m (SD 9.3), 78.9 m (SD 3.3), and 66.1 m (SD 4.1), respectively. These data are consistent with the different wall structures of the three vessels. The rat aortic L p data are quantitatively consistent with rabbit Lp(⌬P) (Tedgui A and Lever MJ.

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Hydraulic conductivity of the endothelial and outer layers of the rabbit aorta

Cited by 35 publications

References 0 publications

Computational modeling of coupled blood-wall mass transport of LDL: effects of local wall shear stress

Computational modeling of coupled blood-wall mass transport of LDL: effects of local wall shear stress

A theory for water and macromolecular transport in the pulmonary artery wall with a detailed comparison to the aorta

Transport in rat vessel walls. I. Hydraulic conductivities of the aorta, pulmonary artery, and inferior vena cava with intact and denuded endothelia

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