Affiliation:
1. Service de Biochimie, INSERM CJF 94–02, Faculté de Médecine Paris-Ouest, Université René Descartes (Paris V) Centre Hospitalier de POISSY, 78303 Poissy Cedex, France
Abstract
Abstract
To investigate the role of sex steroid hormones in adipose tissue development and distribution, we have studied the effect of various sex steroids (testosterone, dihydrotestosterone (DHT), and 17β-estradiol) in vitro, on the proliferation and differentiation processes in rat preadipocytes from deep (epididymal and parametrial) and superficial (femoral sc) fat deposits. All added steroids failed to affect the growth rate of preadipocytes from male rats when determined from day 1 to day 4 after plating, whether FCS was present or not in the culture medium. In contrast, in preadipocytes from female rats, we observed a positive effect (×2) of 17β-estradiol (0.01μ m) on the proliferative capacities of sc but not parametrial preadipocytes. When preadipocytes were exposed to testosterone or DHT (0.1 μm) during the differentiation process, the glycerol 3-phosphate dehydrogenase activity was significantly decreased in epididymal preadipocytes only. When preadipocytes from male rats were exposed to 17β-estradiol (0.01μ m), the differentiation capacities of preadipocytes were not modified. However, in parametrial preadipocytes from ovariectomized female rats, 17β-estradiol significantly increased (×1.34) the glycerol 3-phosphate dehydrogenase activity. In differentiated preadipocytes that had been exposed to sex steroids, expression of peroxisome proliferator-activated receptor γ2 was up-regulated by 17β-estradiol but not by androgens. As described in other cell types, sex steroids modulate insulin growth factor 1 receptor (IGF1R) expression in preadipocytes. Indeed, IGF1R levels were either enhanced by 17 β-estradiol (0.01 μm) in sc preadipocytes from female ovariectomized rats or decreased by DHT (0.01 μm) in epididymal preadipocytes. These effects were reversed by simultaneous exposure to androgen or estrogen receptor antagonists. In conclusion, this study demonstrates that, in rat preadipocytes kept in primary culture and chronically exposed to sex hormones, androgens elicit an antiadipogenic effect, whereas estrogens behave as proadipogenic hormones. Moreover, our results suggest that these opposite effects could be related to changes in IGF1R (androgens and estrogens) and peroxisome proliferator-activated receptor γ2 expression (estrogens).
Reference57 articles.
1. Fat cell metabolism in different regions in women: effect of menstrual cycle, pregnancy and lactation.;Rebuffe-Scrive;J Clin Invest,1985
2. Regional adipose tissue metabolism in men and postmenopausal women.;Rebuffe-Scrive;Int J Obes,1987
3. Long-term testosterone administration increases visceral fat in female to male transsexuals.;Elbers;J Clin Endocrinol Metab,1997
4. Adipose tissue distribution and function.;Bjorntorp;Int J Obes,1991
5. Transcriptional regulation of gene expression during adipocyte differentiation.;McDougald;Annu Rev Biochem,1995
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