| 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. |
