Increased sinusoidal wall permeability and liver fatty change after two-thirds hepatectomy: An ultrastructural study in the rat

Morsiani, E; Mazzoni, M.P.; Aleotti, A; Gorini, P; Ricci, Daniele

doi:10.1002/hep.1840210239

Cited by 11 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Inclusion of "gaps"-those pores larger than 300 m in diameter-as fenestrae could skew the mean diameter to the larger size, especially if there are more "gaps" in zone 1 than zone 3. Our mean porosity measurements also vary from previously published reports, 11,23 but otherwise correlate well in that porosity is greater in zone 3 than in zone 1. 9,23 Previous work has suggested that direction of perfusion, either anterograde or retrograde to inherent blood flow, can influence fenestration size.…”

Section: Discussionsupporting

confidence: 85%

“…This correlation has been shown previously as a general phenomenon in the midlobular region of the sinusoid within 24 hours of resection. 11 Here, we report that a gradient of lipid deposition is spatially and temporally related to the increased fenestration size along the portal-central axis. Under conditions of increased fenestration size in zone 1, chylomicron remnants are not excluded from hepatocytes by the SEC.…”

Section: Discussionmentioning

confidence: 76%

“…(See also vitro and in vivo studies have also shown that fenestrae can modulate their diameter in response to soluble agents as well as a variety of environmental conditions, including changes in shear stress and portal pressure, and pathological ECM deposition. [10][11][12][13][14][15][16][17][18][19] We sought to investigate the trends in porosity expression in the SEC within and between lobule zones throughout the revascularization process following PHx. We believed that such changes may play a critical role in the sieving function of the sinusoids and contribute to the progression of the regenerative process.…”

Section: Discussionmentioning

confidence: 99%

“…9 Fenestrations are thought to regulate flow of these agents by modulating porosity throughout the sinusoidal wall. Therefore, fenestrations are not passive sieves, but are most probably very dynamic structures whose size and density have been shown to be affected by physical factors such as portal pressure and shear stress 10,11 ; soluble substances such as alcohol, 12 serotonin, 13 endotoxin, 14 and nicotine 15 ; and cytoskeletal disruption agents like cytochalasin B, 16,17 as well as the composition of the ECM. 18,19 Given the fact that SEC fenestrations can modulate their diameters in response to a variety of factors and events, we sought to examine fenestration size and sinusoidal porosity index with respect to ultrastructural changes taking place within the regenerating lobule.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Sinusoidal ultrastructure evaluated during the revascularization of regenerating rat liver

et al. 2001

View full text Add to dashboard Cite

Sinusoidal endothelial cell (SEC) porosities were compared between the periportal (zone 1) and pericentral (zone 3) regions of the rat liver during regeneration following partial hepatectomy (PHx). SEC porosities and fenestration diameters were measured in control livers, as well as at 5 minutes, 24, 48, 72, 96, 120 hours, and 14 days following PHx. Bimodal maximums in both porosity and fenestration diameters were observed in both zones at 5 minutes and 5 days following PHx. SEC porosities increased significantly in both zones 1 and 3 within 5 minutes following PHx, but the increase was maintained only in zone 1 at 24 hours after resection. Following the initial rise, both zones displayed a gradual decrease to less than half their porosity values at 72 hr post-PHx. After 72 hours, porosities increased to over control levels and remained elevated until 14 days after PHx. The decrease in porosity at 72 hr post-PHx is accompanied by ultrastructural changes within the sinusoid at this time. Vascular corrosion casting and transmission electron microscopy (TEM) show sinusoid compression resulting from increased hepatic plate widths due to hepatocyte proliferation in the absence of SEC proliferation. Also at this time, we observed many SEC completely enveloped by stellate cells. The zonal variations observed for porosities throughout regeneration did not correlate with changes in laminin, collagen I and IV, or fibronectin deposition within the space of Disse. Taken together, the data reveal that SEC are dynamic regulators of porosity that respond rapidly and locally to environmental zonal stimuli during liver regeneration. (HEPATOLOGY 2001;33:363-378.)Following chemical or mechanical injury, the liver has the extraordinary capacity to regenerate back to its normal mass within a short time. During regeneration, the same physiologic functions required by the organism must be performed with less metabolic "equipment," and therefore the liver must continuously adapt its metabolic output to its rapidly changing architecture. As a result of tissue loss, the concentrations of many factors, including growth factors, cytokines, and proteases, rise in the blood and liver to promote temporal and spatial proliferation and migration of the various cells to efficiently reconstitute the liver mass (reviewed by Michalopoulos 1 and Fausto 2 ). Following 70% partial hepatectomy (PHx) in the rat, hepatocyte DNA synthesis peaks abruptly at 24 hours after PHx, and essentially terminates DNA synthesis by 72 hours following resection. 3 Sinusoidal endothelial cells (SEC), the open, fenestrated, discontinuous endothelial cells that line the vessels supplying the parenchymal plates, do not initiate DNA synthesis until 48 to 72 hours after resection, peaking at 4 d post-PHx, but continue to proliferate at least until 8 days following PHx. [3][4][5] This cellular order of proliferative events results in the formation of avascular hepatic islands throughout the liver lobule. 6 Subsequent proliferation and migration of the sinusoidal endothelium i...

show abstract

Section: Discussionsupporting

confidence: 85%

Section: Discussionmentioning

confidence: 76%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Sinusoidal ultrastructure evaluated during the revascularization of regenerating rat liver

et al. 2001

View full text Add to dashboard Cite

show abstract

“…Variation in the selection of sinusoids for micrographs, image analysis of artefacts, and measurement of cell area for porosity and fenestration frequency have led to major discrepancies in published results. A standardized approach for evaluation and measurement of fenestrations and the minimum requirements for data presentation have not been clearly addressed in the literature previously 4,10,[20][21][22][23][24][25][26][27][28][29][30][31] .…”

Section: Introductionmentioning

confidence: 99%

A Standardized Method for the Analysis of Liver Sinusoidal Endothelial Cells and Their Fenestrations by Scanning Electron Microscopy

Cogger

O'Reilly

Warren

et al. 2015

JoVE

View full text Add to dashboard Cite

Liver sinusoidal endothelial cells are the gateway to the liver, their transcellular fenestrations allow the unimpeded transfer of small and dissolved substances from the blood into the liver parenchyma for metabolism and processing. Fenestrations are dynamic structures -both their size and/ or number can be altered in response to various physiological states, drugs, and disease, making them an important target for modulation. An understanding of how LSEC morphology is influenced by various disease, toxic, and physiological states and how these changes impact on liver function requires accurate measurement of the size and number of fenestrations. In this paper, we describe scanning electron microscopy fixation and processing techniques used in our laboratory to ensure reproducible specimen preparation and accurate interpretation. The methods include perfusion fixation, secondary fixation and dehydration, preparation for the scanning electron microscope and analysis. Finally, we provide a step by step method for standardized image analysis which will benefit all researchers in the field. Video LinkThe video component of this article can be found at

show abstract

Down the liver sinusoidal endothelial cell (LSEC) hole. Is there a role for lipid rafts in LSEC fenestration?

Rodríguez-Vita

Morales-Ruíz

2013

Hepatology

View full text Add to dashboard Cite

Fenestrations are transcellular pores in endothelial cells that facilitate transfer of substrates between blood and the extravascular compartment. In order to understand the regulation and formation of fenestrations, the relationship between membrane rafts and fenestrations was investigated in liver sinusoidal endothelial cells where fenestrations are grouped into sieve plates. Three dimensional structured illumination microscopy, scanning electron microscopy, internal reflectance fluorescence microscopy and two-photon fluorescence microscopy were used to study liver sinusoidal endothelial cells isolated from mice. There was an inverse distribution between sieve plates and membrane rafts visualized by structured illumination microscopy and the fluorescent raft stain, Bodipy FL C5 ganglioside GM1. 7-ketocholesterol and/or cytochalasin D increased both fenestrations and lipid-disordered membrane, while Triton X-100 decreased both fenestrations and lipid-disordered membrane. The effects of cytochalasin D on fenestrations were abrogated by co-administration of Triton X-100, suggesting that actin disruption increases fenestrations by its effects on membrane rafts. Vascular endothelial growth factor (VEGF) depleted lipid-ordered membrane and increased fenestrations. The results are consistent with a sieve-raft interaction, where fenestrations form in non-raft lipid-disordered regions of endothelial cells once the membrane-stabilizing effects of actin cytoskeleton and membrane rafts are diminished. CommentThe endothelial cells are a specialized cell type that line blood and lymphatic vessels and form a monostratified layer called the endothelium. The endothelium may be continuous or discontinuous, and in some tissues the communication between the parenchyma and blood circulation can be finely tuned by the presence of special transcellular pores called fenestrations.

show abstract

Increased sinusoidal wall permeability and liver fatty change after two-thirds hepatectomy: An ultrastructural study in the rat

Cited by 11 publications

References 17 publications

Sinusoidal ultrastructure evaluated during the revascularization of regenerating rat liver

Sinusoidal ultrastructure evaluated during the revascularization of regenerating rat liver

A Standardized Method for the Analysis of Liver Sinusoidal Endothelial Cells and Their Fenestrations by Scanning Electron Microscopy

Down the liver sinusoidal endothelial cell (LSEC) hole. Is there a role for lipid rafts in LSEC fenestration?

Contact Info

Product

Resources

About