[Changes in the lipid concentration in serum, liver and adipose tissue in alimentary obesity in Wistar rats]

In colony-bred Wistar rats maintained for several weeks on a high-percent fatty food (fat content 50%) compared with controls (3% fat in food) the concentrations of the following lipids were determined quantitatively: In serum lipid phosphorus (Lip. P.), free fatty acids (FFA), triglycerides (TG), free cholesterole (FC) and cholesteryl ester (CE), in liver Lip. P,TG, FC and CE, in epididymal adipose tissue Lip. P. FFS and TG. With increasing weight differences between the two animals groups, in the phase of steady weight growth (,,dynamic phase", age of investigation 9 weeks, after 4 weeks on fatty food) a significant rise in serum FFS over the controls is observed with increases in TG and CE concentrations in the liver. After about 20 weeks of life the weight growth slows down; in this subsequent "static phase" the TG and CE accumulation in the liver further increases. Investigation of the epididymal adipose tissue suggests hypertrophy of the adipose cells. The results obtained with both phases are discussed with regard to possible metabolic alterations.