Influence of age on size and number of fat cells in the epididymal depot

Abstract

The extensive literature on the effect of rat age on the size and number of adipocytes in adipose tissue depots relates solely to young developing rats and young adults. Therefore a study was carried out in our laboratory on the cellular characteristics of the epididymal depot of the Fisher 344 strain of rats through virtually the entire life-span. Collagenase digests of this depot prepared from rats of 9, 13, 26, 52, 104, and 130 wk of age yield a population of cells with diameters greater than 30 mum identified as adipocytes or "fat cells." A remarkably complex pattern of changes in both the size and the number of these fat cells in the epididymal depot occurred through the life-span of the rats. The epididymal depots also contain some cells with diameters around 10 mum which have a morphology similar to that of the classic adipocytes; such cells may be preadipocytes.