English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A kinetic model of vitamin E transport in humans is described using data from our studies with deuterium-labeled stereoisomers of alpha-tocopherol (RRR- and SRR-). In normal subjects, both alpha-tocopherols are present at similar concentrations in chylomicrons, but by 24 hr, RRR-alpha-tocopherol is at higher plasma concentrations because RRR-alpha-tocopherol is preferentially incorporated into very low density lipoproteins, which are then secreted into plasma. In three nondiscriminator patients with familial isolated vitamin E deficiency, the fractional disappearance rates (mean +/- SD) of deuterium-labeled RRR- and SRR-alpha-tocopherols in plasma were 1.4 +/- 0.6 and 1.3 +/- 0.3 pools per day, respectively (difference, 0.1 +/- 0.3). In these patients, plasma concentrations of both RRR- and SRR-alpha-tocopherols decreased similarly to SRR-alpha-tocopherol in controls. In six controls, fractional disappearance rates of deuterium-labeled RRR-alpha-tocopherol (0.4 +/- 0.1 pool per day) were significantly (P &lt; 0.01) slower than for SRR- (1.2 +/- 0.6). The differences (0.8 +/- 0.6 pool per day) between these two rates in controls estimate the rate at which RRR-alpha-tocopherol, which had left the plasma, was returned to the plasma. Although plasma labeled RRR-alpha-tocopherol concentrations in controls appear to change slowly, these data show that both RRR- and SRR-alpha-tocopherols leave the plasma rapidly, but only RRR-alpha-tocopherol is returned to the plasma, likely in nascent very low density lipoproteins. This recycling of RRR-alpha-tocopherol accounts for nearly 1 pool of alpha-tocopherol per day.

Human plasma vitamin E kinetics demonstrate rapid recycling of plasma RRR-alpha-tocopherol.