[Effects of arterial hyperpression on the transport and distribution of LDL and albumin in the arterial wall].
To investigate the effect of hyperpressure on the transport of LDL and albumin in the arterial wall, we measured in vitro the uptake of both 131I-LDL and 125I-albumin in intact rabbit thoracic aorta, held at in vivo length and pressurized to 70 or 160 mmHg. Arteries were incubated for 2 h at 70 mmHg, and for 5 min, 30 min, 1 h and 2 h at 160 mmHg. The transmural distribution of the relative concentrations of LDL (CLDL) and albumin (CAlb) across the wall was determined using a serial frozen sectioning technique. At 70 mmHg, the mean medial CLDL and CAlb values were 0.0018 +/- 0.0007 and 0.0039 +/- 0.0013, respectively. At 160 mmHg, CLDL and CAlb were markedly increased. The distribution of labeled albumin was almost uniform across the media and reached a steady state after 30 min, whereas labeled LDL accumulated in the first inner layers, a steady state being achieved after 1 h. The 1-hour values of CLDL in the first and second luminal sections (0.24 +/- 0.03 and 0.13 +/- 0.05, respectively) were much higher than those of CAlb, the CLDL/CAlb ratios being 4.12 +/- 0.94 and 2.34 +/- 0.42 (p less than 0.01), respectively. In the subsequent sections, the CLDL markedly decreased and became much lower than the CAlb, the CLDL/CAlb ratio averaging 0.2 in the two thirds outer media. To investigate whether LDL was trapped at high pressure in the inner layers, vessels were exposed to a tracer-free intraluminal solution for 30 min, following a 30-minute incubation with tracers.(ABSTRACT TRUNCATED AT 250 WORDS)
Curmi
P A
PA
INSERM U 141, Paris.
Juan
L
L
Merval
R
R
Tedgui
A
A
D000818:Animals; D001013:Aorta, Thoracic; D001161:Arteriosclerosis / Q000503:physiopathology; D001692:Biological Transport; D004730:Endothelium, Vascular / Q000737:chemistry / Q000378:metabolism*; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D008077:Lipoproteins, LDL / Q000032:analysis / Q000378:metabolism*; D011817:Rabbits; D012709:Serum Albumin / Q000378:metabolism*; D014018:Tissue Distribution
D008077:Lipoproteins, LDL; D012709:Serum Albumin
Effets de l'hyperpression artérielle sur le transport et la distribution des LDL et de l'albumine dans la paroi artérielle.