Parameters of the three-pool model of the turnover of plasma cholesterol in normal and hyperlipidemic humans.

Abstract

A B S T R A C T Long-term studies (32-49 wk) of the turnover of plasma cholesterol were conducted in 24 subjects. Eight subjects were normolipidemic, six had hypercholesterolemia, eight had hypercholesterolemia and hypertriglyceridemia, and two had hypertriglyceridemia alone. 10 of the hyperlipidemic patients had a definite familial disorder. In all subjects (except one for whom complete data were not available), the same three-pool model previously described gave the best fit for the data. Ml was correlated with all body size variables, but most strongly with excess weight. After adjusting for the effects of body size, M1 was also correlated with the serum concentrations of both cholesterol and triglyceride. Major differences were found in the relationships between the physiological variables and the sizes of pools 2 and 3. M2 was correlated neither with any of the indices of body size or adiposity, nor with the serum levels of either cholesterol or triglyceride. In contrast, all estimates of M3 were correlated with indices of adiposity (but not of overall body size) and with the serum cholesterol concentration.

Lack of effect of lovastatin therapy on the parameters of whole-body cholesterol metabolism.

“…The subjects were all seen at regular intervals by a nutritionist, before and during the turnover studies, to ensure compliance with the diet. The results of these initial cholesterol turnover studies, conducted before the patients received drug therapy, have been reported previously (9,(11)(12)(13).…”

“…The amounts of radioactivity injected (-25 uCi per subject) were measured precisely. Information about the turnover studies that were carried out before drug therapy has been reported in previous publications (9,(11)(12)(13). The repeat cholesterol turnover studies, carried out during drug therapy, were each -280 d in duration.…”

Immunological and immunoassay studies of the binding protein for vitamin D and its metabolites in human serum.

“…The mixtures were centrifuged for 10 min at 1,500 rpm at 4°C. Exactly 1 ml of each supernate was transferred to a scintillation vial, mixed with 10 (18). Samples were obtained as well from five patients with chronic liver disease and from nine patients with chronic renal disease.…”

In vivo tissue cholesterol efflux is reduced in carriers of a mutation in APOA1

“…This would require further studies with apoA-I substitution. Also, our measurement of TCE and FSE does not quantify the effl ux of cholesterol from the lipid laden macrophage via ABC-transporters to HDL for subsequent elimination into the feces ( 3, 7 ), as cholesterol in atherosclerotic plaques represents merely a minute fraction of the total exchangeable cholesterol pool size ( 21,50 ). Assessment of this macrophage-specifi c RCT is currently confi ned to studies in mice ( 3 ).…”