Dietary Cholesterol Content Research Articles

Serum Lipid and Lipoprotein Responses of Six Nonhuman Primate Species to Dietary Changes in Cholesterol Levels

The response of serum lipids and lipoproteins to different levels of cholesterol in the diet was studied in chimpanzee (Pan troglodytes), rhesus (Macaca mulatta), green (Cercopithecus aethiops), patas (Erythrocebus patas), squirrel (Saimiri sciurea) and spider (Ateles sp.) monkeys. Five animals of each species were fed increasing amounts of dietary cholesterol (0.05% to 1.5% W/W) for 3-week periods; between each experimental diet, the animals were fed a basal diet without cholesterol for a similar period. Serum cholesterol response of different species measured in terms of response index (area under the time-concentration curve above basal value) varied with the dietary cholesterol content and showed a significant interspecies difference at 0.5% dietary cholesterol (1.8 mg/kcal) level. The overall response for the different diets allowed ranking of the species as follows: squirrel greater than green greater than spider approximately equal to rhesus approximately equal to patas greater than chimpanzee. The serum lipoprotein response was reflected not only in an increase in beta-lipoprotein but also in alpha-liprotein with significant differences among species in the amount of cholesterol transported in the lipoprotein classes. Challenging the animals with dietary cholesterol seems to be an essential step for determining inter- and intraspecies differences.

Dietary sterol effects on mevalonate kinase activity in axenic and non-axenic Sarcophaga bullata (Diptera)

The effects of dietary sterols on the mevalonate kinase of Sarcophaga bullata larvae have been determined. Larvae reared axenically to day 6 on semi-defined cholesterol and β-sitosterol diets evidence a two- to threefold increase in enzyme specific activity compared to the non-axenic larvae at the same developmental time. Under non-axenic growth conditions, the larva evidences a clear pattern of kinase activity in response to varying dietary cholesterol concentrations. A 50 per cent increase in specific activity is observed when cholesterol concentration is reduced to 1 100 that of the standard dietary optimum (1·0 per cent). Of other sterols studied, β-cholestanol produces the most significant effect on the larval enzyme. Larval growth rate indices and survival determinations have been calculated for the insects reared on cholesterol and β-sitosterol regimens. The results of these investigations are discussed in relation to the effect of nutritional stimuli on enzyme levels in axenic and non-axenic organisms and the control of isoprenoid biosynthesis in this insect.

Dietary myristate and plasma cholesterol concentration.

Dietary myristate and plasma cholesterol concentration.