Diet-induced adipocyte number increase in adult rats: a new model of obesity.

Abstract

Adult rats of various strains became obese when they were fed a highly palatable diet for several months. Analysis of their adipose tissue morphology revealed increases in both adipocyte size and number in most depots. Reintroduction of an ordinary chow diet to such animals precipitated a period of weight loss during which only mean adipocyte size returned to normal. Adipocyte number remained at the elevated level achieved during the period of weight gain. Thus, transient dietary obesity in rats results in a persistent obesity of a purely hyperplastic, nonhypertrophic form. Furthermore, the persistence of the cell number increase suggests that it is the result of proliferation or differentiation rather than of only an increase in the lipid content of a pool of very small and normally undetected adipocytes. An analysis of adipose tissue morphology changes during the course of diet-induced weight gain suggests that the achievement of some specific mean adipocyte size triggers the events that culminate in adipocyte number increase. What mechanisms may link adipocyte size to the formation of new adipocytes remains unknown.

The influence of maternal nutrition on expression of genes responsible for adipogenesis and myogenesis in the bovine fetus

“…Increasing adipogenesis in the developing muscle increases intramuscular fat and thereby has the potential to increase beef flavor in the mature animal (Du et al, 2015). Although new adipocytes are readily generated during postnatal growth, they are primarily located in fat depots other than intramuscular fat, as evident in rodent models (Faust et al, 1978;Valet et al, 2002), and therefore do not contribute to beef flavor. Similar findings have been reported based upon serial ultrasound measurements and serial slaughters in beef cattle.…”

Time-Dependent Effects of a High-Energy-Yielding Diet on the Regulation of Specific White Adipose Tissue Genes

“…Some genes, such as PPAR␥2, appear to play an important role in activating the adipocyte differentiation program and in the regulation of mature WAT genes (10,21). Also, uncoupling proteins and aP2 have been studied to evaluate the potential influence of nutrients on adaptive thermogenesis and to elucidate whether dietary manipulations directly affect the gene expression pattern of adipocytes (9,19,22).…”

“…In addition to this age dependent changes, cell number and size could be augmented by high-carbohydrate or high-fat diets, which may, in turn, depend on gene predisposition (8,9).…”

Nϵ‐Carboxymethyllysine Increases the Expression of miR‐103/143 and Enhances Lipid Accumulation in 3T3‐L1 Cells

“…The effects of AGEs on adipogenesis may be of particular interest in the context of adipogenesis in adults, where one‐tenth of the adipocytes are renewed every year [Hausman et al, 2001; Spalding et al, 2008]. Furthermore, diet‐induced hyperplastic, nonhypertrophic obesity has been shown in experiments on rats on highly palatable chow, during which adipocyte number increased, and remained high after a return to a standard diet, while only adipocyte size returned to normal [Faust et al, 1978]. Adipose tissue is not only important in the context of lipid storage, adipokines secreted from adipose tissue have been shown to be involved in metabolic homeostasis by interacting with peripheral, or central organs [Harwood, 2012].…”