dc.contributor.author |
Vaghefi Rezaei, Seyed |
en |
dc.contributor.author |
Donaldson, Paul |
en |
dc.date.accessioned |
2019-02-26T22:50:53Z |
en |
dc.date.issued |
2018-11 |
en |
dc.identifier.citation |
American journal of physiology. Regulatory, integrative and comparative physiology 315(5):R994-R1002 Nov 2018 |
en |
dc.identifier.issn |
0363-6119 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/45530 |
en |
dc.description.abstract |
It has been proposed that optical properties of the lens are actively maintained by an internal microcirculation system that utilizes ionic and fluid fluxes to deliver nutrients to deeper regions of the lens tissue via the extracellular space faster than would occur by passive diffusion alone. To test this hypothesis, we utilized a range of commercially available magnetic resonance imaging (MRI) reagents of varying molecular sizes that served as tracers of extracellular solute delivery. The penetration of these tracers into bovine lenses incubated in the absence and presence of solutions that inhibit the microcirculation was monitored in real time over a 4-h period using T1-weighted MRI. We found that only the smaller contrast agents were delivered to the core of the lens and that the rate of solute penetration was significantly faster than that calculated simple diffusion. Next, the lenses were first incubated in either high extracellular K+ to depolarize the lens potential or ouabain to inhibit the Na+ pump. These two perturbations are known to inhibit the circulating ionic and fluid fluxes that are proposed to drive solute delivery into the lens core. Both perturbations inhibited the delivery of the extracellular tracer molecules to the lens core. Our findings suggest that the microcirculation system can potentially be harnessed to deliver exogenous antioxidants to the lens core to afford mature fiber cells protection against oxidative damage that ultimately manifests as age-related nuclear cataract. |
en |
dc.format.medium |
Print-Electronic |
en |
dc.language |
eng |
en |
dc.relation.ispartofseries |
American journal of physiology. Regulatory, integrative and comparative physiology |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.rights.uri |
https://www.physiology.org/author-info.permissions |
en |
dc.subject |
Microcirculation |
en |
dc.subject |
Lens, Crystalline |
en |
dc.subject |
Extracellular Space |
en |
dc.subject |
Animals |
en |
dc.subject |
Cattle |
en |
dc.subject |
Cataract |
en |
dc.subject |
Contrast Media |
en |
dc.subject |
Magnetic Resonance Imaging |
en |
dc.subject |
Diffusion |
en |
dc.title |
The lens internal microcirculation system delivers solutes to the lens core faster than would be predicted by passive diffusion. |
en |
dc.type |
Journal Article |
en |
dc.identifier.doi |
10.1152/ajpregu.00180.2018 |
en |
pubs.issue |
5 |
en |
pubs.begin-page |
R994 |
en |
pubs.volume |
315 |
en |
dc.rights.holder |
Copyright: The American Physiological Society |
en |
pubs.end-page |
R1002 |
en |
pubs.publication-status |
Published |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/RestrictedAccess |
en |
pubs.subtype |
Research Support, Non-U.S. Gov't |
en |
pubs.subtype |
Journal Article |
en |
pubs.elements-id |
757863 |
en |
pubs.org-id |
Bioengineering Institute |
en |
pubs.org-id |
ABI Associates |
en |
pubs.org-id |
Medical and Health Sciences |
en |
pubs.org-id |
Medical Sciences |
en |
pubs.org-id |
Optometry and Vision Science |
en |
dc.identifier.eissn |
1522-1490 |
en |
pubs.record-created-at-source-date |
2018-08-30 |
en |
pubs.dimensions-id |
30156422 |
en |