Dehydroepiandrosterone modifies rat fatty acid composition of serum and different adipose tissue depots and lowers serum insulin levels

Abstract

Dehydroepiandrosterone (DHEA) is reported to exert beneficial effects, such as protection from cardiovascular risk and lowering serum insulin levels. Adipose tissue (AT) is a target for DHEA actions, and the hormone can also affect hepatic fatty acid (FA) metabolism. FAs are involved in the development of insulin resistance; thus, there might be a relationship between DHEA, FA, and insulin. However, few data are available regarding DHEA and FA composition, especially concerning AT. Seventeen-month old female Sprague-Dawley rats (nZ11; controls: nZ10) were treated with DHEA (0 . 5% w/w in the diet) for 13 weeks, after which serum, periovarian, mesenteric, s.c., and brown AT were analyzed for FA composition. DHEA treatment resulted in significant changes in FA profiles in serum and adipose depots, like reduced 16:1n-7 (s.c. and brown AT; P!0 . 01), elevated n-9 monounsaturated FA (serum and s.c. AT; P!0 . 05), diminished n-6 polyunsaturated FA (PUFA; general; P!0 . 05) and increased n-3 PUFA (brown AT; P!0 . 01), along with lower n-6/n-3 ratios (s.c. and brown AT; P!0 . 05, P!0 . 01 respectively). DHEA modified estimates of desaturase activities, decreasing stearoyl-CoAdesaturase markers in s.c., and brown AT (P!0 . 05) and increasing those of delta-6-desaturase in serum and AT (P!0 . 05). In addition, DHEA-treated rats showed lower serum insulin levels (P!0 . 05). We have demonstrated for the first time that DHEA induces significant modifications in AT fatty acid composition in vivo, mainly concerning unsaturated FAs, and changes occurred in a tissue-dependent manner. We propose that these changes may be related to the capacity of DHEA to lower serum insulin levels.

Dehydroepiandrosterone-Sulfate Modifies Human Fatty Acid Composition of Different Adipose Tissue Depots

“…d Estimates of delta-5-desaturase activity. Single asterisk represents significant differences at P<0.05 studies regarding AT fatty acid composition performed in rodents showed a similar trend to our observations [16]. Further studies should explore this situation in vivo.…”

“…More recently, and in the line of the present study, other authors have reported differences in 3T3-L1 adipocytes [25], especially as regards a decrease in palmitic acid. Our own group has formerly shown that DHEA supplementation can modify the AT fatty acid profile of rodents in the same way as the present results shows in humans [16].…”

“…In fact, our own group has demonstrated that prolonged DHEA treatment in rodents induces significant modifications in adipose tissue fatty acid composition, decreasing the n−6 polyunsaturated fatty acid percentage in a tissue-dependent manner [16]. The association between a low proportion of unsaturated or a high proportion of saturated fatty acids and obesity alterations has long been established [17,18].…”

The Role of Site-Specific Adipose Tissue Fatty Acid Composition in Obesity

“…In our laboratory, we observed that rats receiving DHEA orally for 13 weeks reproduced some of the changes observed in 3T3-L1 cells. Besides having a significantly lower percentage body fat, DHEA-treated rats had higher proportions of stearic and oleic acids and a lower proportion of palmitoleic acid in their adipose depots [56]. Total n-6 PUFAs were also decreased, while n-3 PUFAs were increased, leading to significant reductions in n-6:n-3 PUFA ratios.…”

“…A good example is provided by data showing the effects of dehydroepiandrosterone (DHEA) and its sulfate on experimental animals and humans [55][56][57]. The level of this particular hormone, a precursor of most androgens and estrogens, is strongly related to body fat distribution and also with fatty acid profiles of adipose tissue and plasma.…”