Dietary fat up-regulates the apolipoprotein E mRNA level in the Zucker lean rat brain

High-fat diet alters apo E-dependent processing of beta -amyloid precursor protein. Here we have evaluated the effects of dietary fat on brain apo E m RNA in Zucker lean and obese rats. After similar to2 months on a high-fat d iet, there was significant up-regulation of brain apo E mRNA in the Zucker lean rat in parallel with weight gain. Densitometric quantification reveale d a 17% increase in apo E mRNA in the brains of lean rats fed high-fat diet compared with those of lean rats fed rat chow. No significant difference i n brain apo E mRNA of Zucker obese rats fed different diets was found. Thes e results suggest that dietary fat alters brain apo E levels, which may be regulated, in part, through the leptin receptor. NeuroReport 12:3111-3115 ( C) 2001 Lippincott Williams & Wilkins.