In:
Circulation, Ovid Technologies (Wolters Kluwer Health), Vol. 94, No. 7 ( 1996-10), p. 1698-1704
Abstract:
Background The aim of the present study was to investigate whether oxidized LDL (ox-LDL) in the arterial intima could be derived from LDL already oxidized in plasma. Methods and Results Rabbits received an intravenous injection of 125 I-labeled normal LDL (N-LDL) mixed with 131 I-labeled LDL that had been mildly oxidized through exposure to Cu 2+ . The aortic accumulation of undegraded labeled LDL was expressed as plasma equivalents and calculated as radioactivity in the intima/inner media (cpm/cm 2 ) divided by the time-averaged concentration of radioactivity in plasma (cpm/nL): for the thoracic aorta, the accumulation of undegraded ox-LDL in the intima/inner media exceeded that of undegraded N-LDL by 286% (n=6, P 〈 .04), 863% (n=7, P 〈 .02), and 364% (n=8, P 〈 .01) after 1, 3, and 24 hours of exposure, respectively. There was a strong positive association between the extent of oxidation and the excess accumulation of undegraded ox-LDL compared with N-LDL (thoracic aorta; 3 hours of exposure: r =.97, n=14, P 〈 .00001). To measure degradation of N-LDL and ox-LDL, 125 I-LDL labeled with 131 I-tyramine cellobiose was injected intravenously 24 hours before the aortic intima/inner media was removed: for the thoracic aorta, the accumulation of degradation products from ox-LDL (n=6) exceeded that from N-LDL (n=6) by 301% ( P 〈 .04). Conclusions The present data suggest a novel mechanism: mildly oxidized LDL may circulate in plasma for a period sufficiently long to enter, accumulate, and be degraded in the arterial intima in preference to N-LDL.
Type of Medium:
Online Resource
ISSN:
0009-7322
,
1524-4539
DOI:
10.1161/01.CIR.94.7.1698
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
1996
detail.hit.zdb_id:
1466401-X
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