The age-related rise of plasma cholesterol in humans is not caused by a cell removal defect of LDL particles: 'in vitro' studies in peripheral mononuclear blood cells.
In healthy subjects with a normal body mass index, total plasma cholesterol, low-density lipoprotein (LDL) cholesterol, and apoB lipoprotein levels are higher in older individuals (n = 34) than in younger subjects (n = 43). The two groups studied ranged in age from 60 to 93 years and from 17 to 30 years, respectively. The cholesterol synthesis rates of peripheral mononuclear blood cells from 14C-acetate, total and unesterified cholesterol concentrations in freshly isolated cells, and the rates of uptake of pooled donor LDL, labeled with 125I- or 14C-cholesteryl oleoyl ether, by cells derepressed in a lipoprotein-free medium were similar in both experimental groups. Thus, the rise of LDL cholesterol with age would seem to be likely secondary to the higher rate of very-low-density lipoprotein production, as shown by other investigators.
Neves
M Q
MQ
Department of Internal Medicine, University of São Paulo Medical School, Brazil.
Carvalho
M D
MD
Passarelli
M
M
Nakandakare
E R
ER
Bernik
M M
MM
Quintão
E C
EC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001055:Apolipoproteins B / Q000097:blood* / Q000378:metabolism; D002250:Carbon Radioisotopes; D002784:Cholesterol / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011973:Receptors, LDL / Q000235:genetics / Q000502:physiology*
D001055:Apolipoproteins B; D002250:Carbon Radioisotopes; D008078:Cholesterol, LDL; D011973:Receptors, LDL; D002784:Cholesterol