Inhibition of cholesterol uptake by the arterial wall in the intact animal
Bing, R.J.; Sarma, J.S.; Chan, S.I.
Artery 5(1): 14-28
1979
ISSN/ISBN: 0098-6127 PMID: 539913 Document Number: 148892
This report presents evidence that 7-ketocholesterol effectively inhibits cholesterol uptake by the arterial wall in intact rabbits. The 7-ketocholesterol was administered to the animals by infusing isologous blood pre-incubated with the sterol. Each animal was used as its own control by the use of 3H and 14C-labelled cholesterols as tracers to measure the arterial cholesterol uptake during two successive infusions. The mean cholesterol uptake by the carotid and femoral arteries in the presence of 7-ketocholesterol was 18+/-3 nmoles/g, whereas the average of cholesterol uptake by these arteries was 53+/-5 nmoles/g when the animals were infused with isologous blood containing no 7-ketocholesterol. The mean concentration of 7-ketocholesterol in the animals blood ranged from 34 to 87 nmoles/ml. In preliminary experiments in vitro, pre-incubation of plasma with particulate 7-ketocholesterol caused inhibition of cholesterol uptake by perfused pig coronary arteries, although the particulate fraction of 7-ketocholesterol was removed prior to perfusion. The mean cholesterol uptake by the arteries perfused with plasma containing 7-ketocholesterol (240+/-20 nmoles/ml) was 96+/-21 nmoles/g, whereas the mean cholesterol uptake of the paired controls was 324+/-86 nmoles/g. The 7-ketocholesterol was found to bind to the lipoproteins and with higher affinity to red cells.