Changes in apoprotein distribution between lipoprotein classes of hypercholesterolemic rats treated with ascorbate

Area of Science:

• Biochemistry
• Lipid Metabolism
• Nutritional Science

Background:

• Ascorbate (vitamin C) is known to reduce lipid levels and apolipoprotein B in rats on a high-cholesterol diet.
• The precise role of ascorbate in modulating lipid metabolism, particularly apolipoprotein profiles, requires further elucidation.

Purpose of the Study:

• To investigate the effects of ascorbate administration on the apolipoprotein pattern in Wistar male rats fed a cholesterol-enriched (Nath) diet.
• To understand how ascorbate influences the distribution and levels of various apolipoproteins within different lipoprotein classes.

Main Methods:

• Wistar male rats were fed a Nath diet for two months, followed by intraperitoneal ascorbate administration (60 mg/kg) for 10 days.
• Blood samples were collected pre- and post-treatment for lipoprotein isolation via ultracentrifugation.
• Apoprotein content was quantified using densitometric scanning of electrophoretic patterns.

Main Results:

• Ascorbate treatment led to decreased plasma cholesterol, triglycerides, and lipoprotein-associated lipids and proteins.
• Significant alterations in apolipoprotein profiles were observed across all lipoprotein classes.
• Specifically, increases in apo E in VLDL-IDL and LDL, and changes in apo C, AI, and B levels were noted, alongside reciprocal changes in HDL.

Conclusions:

• Ascorbate administration effectively lowers plasma lipids in hypercholesterolemic rats.
• These lipid-lowering effects are associated with substantial modifications in the apolipoprotein composition of all major lipoprotein fractions.
• The findings highlight ascorbate's complex role in regulating lipoprotein metabolism and apolipoprotein expression.