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C Doucet

Publications and source records attributed to C Doucet.

43 records · Page 3Linked to original sources

Effect of an hypercholesterolemic diet on the level of several serum lipids and apolipoproteins in nine rat strains.

To detect the response of different strains of rats to an hypercholesterolemic diet, 9 different strains of male rats were fed successively a control diet (C) containing 20% casein for 4 weeks, then a high-protein, cholesterol-rich diet (HC) containing 50% casein and 1.2% cholesterol for 12 weeks. When the rats were fed the control diet, the highest cholesterolemia was found in the LOU strain and the lowest in the WAG and Brown-Norway (BN) strains. The latter strain had the highest free to esterified cholesterol ratio and showed a marked band in beta position (LDL) on agarose gel electrophoresis. Administration of the HC diet induced an increase of cholesterolemia in all the strains except in Fisher (FIS) and LOU. This hypercholesterolemic diet decreased the free to esterified cholesterol ratio only in the BN and FIS strains. On agarose gel, all the strains showed a highly increased band in pre-beta position (VLDL). On polyacrylamide gel, a single, tight band in HDL position was revealed in the BN strain, while a large band or two bands were seen in the other strains. The percentages of some apoproteins in serum total lipoproteins were determined in rats fed the HC diet; the apoprotein E level was inversely correlated to the difference between the cholesterolemia of the rats given the HC and C diets (r = - 0.72; P less than 0.05). So, the BN rats had the lowest apo E level with the highest cholesterolemia increase due to the HC diet.

Animals↗

Effects of whey protein, casein, soya-bean and sunflower proteins on the serum, tissue and faecal steroids in rats.

Four groups of rats were fed for 49 d on one of four semi-purified diets, without added cholesterol and containing 230 g/kg of the following isolated proteins: casein, whey, soya-bean or sunflower. Whey, soya-bean and sunflower proteins, when compared with casein, decreased the level of serum high-density-lipoprotein (HDL)-cholesterol. These low cholesterol levels were accompanied by an increase in the daily faecal excretion of neutral sterols and bile acids in the case of soya-bean protein, and by a decrease in the liver cholesterol content, when rats were fed on whey protein. Considering the amino acid composition of the four purified proteins, we observed that serum total and HDL-cholesterol levels had a significant positive correlation with tyrosine and glutamic acid, and a negative correlation with cystine and alanine. The present study showed that the hypocholesterolaemic effect of dietary proteins was not related to their animal or vegetable origin.

Animals↗

Effects of soy protein and saponins on serum, tissue and feces steroids in rat.

Four groups of rats were fed, for 45 days, one of the following semipurified diets containing sucrose 55% (w/w) and (a) casein 25%, (b) casein 24%, saponins (from Saponaria officinalis) 1%, (c) isolated soy protein 25%, (d) soy protein 24%, saponins 1%. The soy protein diet, compared to the casein one, produced an increase in the fecal excretion of neutral sterols on the 29th and 42nd days, without any modification in the liver, aorta and serum cholesterol concentrations. The effect of soy protein cannot be attributed to its saponin content but other substances associated to soy protein may interfere. With the casein diet, added saponins increased the fecal excretion of neutral sterols and bile acids and decreased liver and aorta cholesterol levels. Serum cholesterol was found unchanged. The effects of saponins were suppressed or greatly reduced with the soy protein diet. These results could be explained by binding of the sterols in insoluble forms.

Animals↗

The scripting of activities of daily living in normal aging: anticipation and shifting deficits with preservation of sequencing.

The purpose of this study was to elaborate upon Shallice's frontal lobe model by evaluating 20 elderly normal and 20 young adult controls, all women, with cognitive tests, a paper-pencil script generation task and a kitchenette meal preparation task. The elderly were significantly weaker on standardized tests of executive functions and on the paper-pencil script generation task. An anticipation and a sequencing impairment clearly emerged. Though anticipation and shifting were compromised in the kitchenette script task, sequencing was however preserved. This supports Shallice's notion according to which scripting is hierarchically organized with top level components being more frontal lobe dependent (supervisory attentional system or SAS) and the lower level components more tributary to subcortical circuits involving procedural learning (contention scheduling or CS).

Activities of Daily Living↗