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.

Characterization of Transplanted Green Fluorescent Protein+ Bone Marrow Cells into Adipose Tissue

“…The determination of a population of cells other than adipocytes was first made in the mid-1970s. In 1975, Stiles et al documented a morphologically different phenotype of cells in human adipose tissue [1]. In 1976, Dardick et al determined that these cells can differentiate into adipocytes [2].…”

Preweaning food intake influences the adiposity of young adult baboons.

“…The mean diameter of adipocytes was measured by the method of Di Girolamo et al (24) as modified by Stiles et al (25). Briefly, adipocytes were isolated from a portion of adipose tissue by collagenase digestion and the cell diameters ofthe adipocytes were measured microscopically.…”

“…A portion of each fat depot was extracted for triglycerides, and triglyceride content of the extract was measured by previously described methods (25,28). Fat cell number was calculated by dividing the total volume of triglyceride per depot by the mean adipocyte volume.…”

Partial Replacement of Waxy Cornstarch by Recrystallized Amylose Retards the Development of Insulin Resistance in Rats

“…Although the adipocyte size was not measured in this study, it is well known that the increased adipose tissue mass seen with the obesity may be the result of adipocyte hypertrophy, hyperplasia, or a combination of the two. 26,27) Hypertrophy of the adipocytes due to obesity decreases the release of adiponectin into the blood, and the release of free fatty acids is inversely increased as a result of the activation of hormone-sensitive lipase. 28) In the present study, there was no difference in the serum adiponectin concentration between the groups when the animals were sacrificed, but the serum free fatty acid concentration was significantly lower in the RCA diet group than in the WCS diet group.…”