Effect of Diet upon the in vitro Metabolism of Rat Epididymal Adipose Tissue

Abstract

Diet composition has a pronounced effect upon the lipogenic and lipolytic abilities of epididymal adipose tissue in vitro. The level of dietary fat is an important variable in that high fat diets depress in vitro lipogenesis. On the other hand, this is not a uniform characteristic of all fats since their effect is variable, depending upon the kind of dietary fat. However, the lipogenic activities of tissues from rats fed two crude diets were less when compared with tissues from rats fed purified diets of a similar fat content. Hence, some factor other than dietary fat is presumably involved in these instances. Rats were fed crude and purified diets for several weeks in order to study their effects on the in vitro release of fatty acids from rat epididymal tissue. The purified diets were isocaloric and differed only in the kind and amount of dietary fat. It was found that the total quantities of fatty acids released during a 4-hour incubation period of epididymal adipose tissue from the various groups of rats were not significantly different. However, the adipose tissue fatty acids were released in proportions different from those initially present in the parent tissues. Palmitoleic was released in relatively greater and oleic acid in lesser amounts than expected from the tissue composition. There was no difference in the extractable lipolytic activity of epididymal adipose tissue from rats fed several dietary fats.