Endothelial Cells Actively Concentrate Insulin During its Transendothelial Transport. (11th July 2013)

• Record Type: Journal Article
• Authors: Genders, Amanda J.; Frison, Vera; Abramson, Sarah R.; Barrett, Eugene J.
• Is Part Of: Microcirculation. Volume 20:Number 5(2013:Jul.)
• Page Start: 434
• Page End: 439
• Publication Date: 2013-07-11
• Subjects: Biological transport -- Periodicals; Microcirculation -- Physiology -- Periodicals; 612.135
• DOI: 10.1111/micc.12044
• Languages: English
• ISSNs: 1073-9688

Abstract

<abstract abstract-type="main" id="micc12044-abs-0001"> <title>Abstract</title> <sec id="micc12044-sec-0001" sec-type="section"> <title>Objective</title> <p>We examined insulins uptake and transendothelial transport by endothelial cells in order to: (i) ascertain whether insulin accumulates within the cells to concentrations greater than in the media; (ii) compare trans endothelial insulin transport to that of inulin (using the latter as a tracer for passive transport or leaked); and; (iii) determine whether insulins transported depended on insulin action.</p> </sec> <sec id="micc12044-sec-0002" sec-type="section"> <title>Methods</title> <p>Using 125I‐insulin at physiologic concentrations we measured both the uptake and trans endothelial transport of insulin by bovine aortic endothelial cells and measured cell volume using tritiated 3‐O‐methylglucose.</p> </sec> <sec id="micc12044-sec-0003" sec-type="section"> <title>Results</title> <p>Bovine aortic endothelial cells accumulate insulin to > five‐fold above the media concentrations and the trans endothelial transport of insulin, but not inulin, is saturable and requires intact PI‐3‐kinase and MEK signaling.</p> </sec> <sec id="micc12044-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The insulin receptor and downstream signaling from the receptor regulates endothelial insulin transport. Insulin is accumulated against a concentration gradient by the endothelial cell. We suggest that insulin uptake is rate limiting for insulin trans endothelial transport.</p> </sec> </abstract>