Morphometric Characteristics of Central Retinal Artery and Vein Endothelium in the Normal Human Optic Nerve Head

Kang, Min Sung; Balaratnasingam, Chandrakumar; Yu, Paula K.; Morgan, William H.; McAllister, Ian L.; Cringle, Stephen J.; Yu, Dao‐Yi

doi:10.1167/iovs.10-6366

Cited by 43 publications

(25 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent studies have identified location-specific phenotypic differences of endothelium at the level of venous microvasculature. Studies of endothelial cell morphology in the central and branch retinal veins in human donor eyes 33,34 have found site-specific changes at these locations known to be vulnerable to venous occlusive diseases. A concept of a local venous constriction induced by vasoconstrictive molecules diffusing from neighboring diseased arteries and/or from other neighboring (hypoxic) tissues has been proposed.…”

Section: Discussionmentioning

confidence: 99%

Local Modulation of Retinal Vein Tone

Cringle

et al. 2016

Invest. Ophthalmol. Vis. Sci.

Self Cite

View full text Add to dashboard Cite

PURPOSE. To determine whether vascular tone of isolated porcine retinal veins can be modulated by tissue-generated vasoactive factors such as endothelin-1 and adenosine. Such information may be useful in understanding the role of the retinal veins in regulating blood flow, and also provide a model for investigating new hypotheses suggesting a role for vasoactive factors in retinal vascular diseases such as retinal vein occlusion.METHODS. An isolated perfused retinal vein preparation was used for this study. Segments of porcine retinal veins were dissected, cannulated, and perfused, and their diameter was monitored during vasoactive agent application of increasing doses of endothelin-1 (10 À12 -10 À8 M) or adenosine (10 À10 -10 À4 M). Adenosine (10 À6 M) was also applied on veins during preconstriction with endothelin-1 (10 À8 M). The significance of any induced change in vessel diameter was assessed in relation to the baseline vessel diameter prior to any drug delivery.RESULTS. Dose-dependent vasocontractile responses were induced by endothelin-1 administration. Endothelin-1 produced a significant contraction at doses of 10 À11 M and above. At 10 À8 M the maximal endothelin-1-induced contractions were to 70.2 6 2.1% of baseline. Adenosine produced a dose-dependent dilation reaching 113.0 6 2.4% at 10 À4 M. Adenosine (10 À6 M) induced a significant dilation in endothelin-1 (10 À8 M)-contracted vessels.CONCLUSIONS. Porcine retinal veins can be modulated by both vasocontraction and vasodilation agents, suggesting that the retinal veins may play a regulatory role in the retinal circulation, particularly in regard to the capillary pressure upstream from the draining retinal veins. To our knowledge, this is the first study of vasoactivity in isolated perfused retinal veins, providing an opportunity to study the direct vasoactive effects of specific vasoactive agents.

show abstract

Section: Discussionmentioning

confidence: 99%

Local Modulation of Retinal Vein Tone

Cringle

et al. 2016

Invest. Ophthalmol. Vis. Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Intra-luminal microperfusion and staining technique has been established in our laboratory and used for study on retinal and choroidal vasculature (Adam et al, 1997;Chan et al, 2013;Kang et al, 2011Kang et al, , 2013Tan et al, 2012;Tan et al, 2013;Yu et al, 2014Yu et al, , 2010aYu et al, , 2010bYu et al, , 2013Yu et al, , 2012. Advantages of this technique include full perfusion fixation of the tissues and intact vasculature and endothelium in situ.…”

Section: Discussionmentioning

confidence: 99%

Quantitative study of the microvasculature and its endothelial cells in the porcine iris

Yang

Cringle

et al. 2015

Experimental Eye Research

Self Cite

View full text Add to dashboard Cite

“…Currently, most of the vascular remodelling studies focus on large arteries and arterioles but only a few have investigated remodelling in microvessels, a site that allows macromolecules to escape, resulting in tissue oedema and organ dysfunction (Yuan and He, 2012). We have previously reported vascular modelling in the specific sites of the retinal vein, arteriovenous crossing and laminar cribrosa region where risk sites for retinal vein occlusion are present (Kang et al, 2011(Kang et al, , 2013Yu et al, 2014;Yu et al, 2012). Identifying the structural and functional changes in iris microvascular endothelial cells and their impact on microvessel permeability will be crucial for a better understanding of the pathogenesis of related vascular diseases and thereby benefit the development of targeted therapies.…”

Section: Discussionmentioning

confidence: 99%

“…Endothelial cell length (ECL) measurements were taken as the longitudinal distance from the upstream pole to the downstream pole. Nuclei position was defined as the distance from the nuclear edge to the cell apex in the downstream direction of blood flow (hereafter denoted as variable e) (Kang et al, 2011). The ratio of e to ECL was considered as normalized nuclei position regardless of endothelial cellular size.…”

Section: Image Analysismentioning

confidence: 99%

Intracellular cytoskeleton and junction proteins of endothelial cells in the porcine iris microvasculature

Yang

Cringle

et al. 2015

Experimental Eye Research

Self Cite

View full text Add to dashboard Cite

Recently we reported studies of the iris microvasculature and its endothelial cells using intra-luminal micro-perfusion, fixation, and silver staining, suggesting that the iris vascular endothelium may be crucial for maintaining homeostasis in the ocular anterior segment. Here we present information regarding the intracellular structure and cell junctions of the iris endothelium. Thirty-seven porcine eyes were used for this study. The temporal long posterior ciliary artery was cannulated to assess the iris microvascular network and its endothelium using intra-luminal micro-perfusion, fixation, and staining with phalloidin for intracellular cytoskeleton f-actin, and with antibodies against claudin-5 and VE-cadherin for junction proteins. Nuclei were counterstained with Hoechst. The iris was flat-mounted for confocal imaging. The iris microvasculature was studied for its distribution, branch orders and endothelial morphometrics with endothelial cell length measured for each vessel order. Our results showed that morphometrics of the iris microvasculature was comparable with our previous silver staining. Abundant stress fibres and peripheral border staining were seen within the endothelial cells in larger arteries. An obvious decrease in cytoplasmic stress fibres was evident further downstream in the smaller arterioles, and they tended to be absent from capillaries and veins. Endothelial intercellular junctions throughout the iris vasculature were VE-cadherin and claudin-5 immuno-positive, indicating the presence of both adherent junctions and tight junctions between vascular endothelial cells throughout the iris microvasculature. Unevenness of claudin-5 staining was noted along the endothelial cell borders in almost every order of vessels, especially in veins and small arterioles. Our results suggest that significant heterogeneity of intracellular structure and junction proteins is present in different orders of the iris vasculature in addition to vascular diameter and shape of the endothelia. Detailed information of the topography and intracellular structure and junction proteins of the endothelium of the iris microvasculature combined with unique structural features of the iris may help us to further understand the physiological and pathogenic roles of the iris vasculature in relevant ocular diseases.

show abstract

Morphometric Characteristics of Central Retinal Artery and Vein Endothelium in the Normal Human Optic Nerve Head

Cited by 43 publications

References 56 publications

Local Modulation of Retinal Vein Tone

Local Modulation of Retinal Vein Tone

Quantitative study of the microvasculature and its endothelial cells in the porcine iris

Intracellular cytoskeleton and junction proteins of endothelial cells in the porcine iris microvasculature

Contact Info

Product

Resources

About