Details

Autor(en) / Beteiligte

• Brenner, Rodolfo R
• Bernasconi, Ana M
• González, María S
• Rimoldi, Omar J

Titel

Dietary cholesterol modulates [Delta]6 and [Delta]9 desaturase mRNAs and enzymatic activity in rats fed a low-EFA diet

Ist Teil von

• Lipids, 2002-04, Vol.37 (4), p.375

Ort / Verlag

Heidelberg: Springer Nature B.V

Erscheinungsjahr

2002

Quelle

2022 ECC(Springer)

Beschreibungen/Notizen

• The effects of a 1% addition of cholesterol to a diet low in EFA on FA desaturases were examined. The administration of cholesterol markedly increased the esterified cholesterol content in microsomes and total liver lipids from the first day, whereas the proportion of free cholesterol remained unaltered throughout the treatment. An excellent homeostasis in the free cholesterol content was apparently evoked by the acyl-CoA cholesterol acyltransferase. The cholesterol esters were mainly oleate, palmitate, and stearate, and the addition of cholesterol increased the relative proportions of cholesterol palmitoleate and oleate. The addition of cholesterol to a low-EFA diet induced, as in animals fed a high-FFA diet, a marked increase in liver stearoyl-CoA desaturase-1 mRNA and enzyme activity. This increased activity apparently evoked a similar enhancement of palmitoleic and oleic acids in total and microsomal liver lipids. The cholesterol-rich diet depressed the liver Δ6 and Δ5 desaturase activity. However, the abundance of Δ6 desaturase mRNA was not modified throughout the treatment. This indicates that the depressive effect is evoked at a step beyond that controlled by the mRNA level. The depression of both enzymatic activities was consistent with the decrease in the percentages of arachidonic acid and DHA in total and microsomal liver lipids. Taken together, these results indicate that through its modulating effect on the desaturases, dietary cholesterol may lead an animal or humaan fed low-EFA diet to a true deficiency by the decreased synthesis of the highly polyunsaturated acids derived from linoleic and α-linolenic acids.[PUBLICATION ABSTRACT]