A soyabean diet does not modify the activity of brown adipose tissue but alters the rate of lipolysis in the retroperitoneal white adipose tissue of male rats recovering from early-life malnutrition

Abstract

Nutritional recovery with a soyabean diet decreases body and fat weights when compared with a casein diet. We investigated whether the reduced adiposity observed in rats recovering from early-life malnutrition with a soyabean diet results from alterations in lipid metabolism in white adipose tissue (WAT) and/or brown adipose tissue (BAT). Male rats from mothers fed either 17 or 6 % protein during pregnancy and lactation were maintained on 17 % casein (CC and LC groups), 17 % soyabean (CS and LS groups) or 6 % casein (LL group) diets over 60 d. The rats maintained on a soyabean diet had similar relative food intakes, but lower body and retroperitoneal WAT weights and a reduced lipid content in the retroperitoneal WAT. The insulin levels were lower in the recovered rats and were elevated in those fed a soyabean diet. Serum T3 concentration and uncoupling protein 1 content in the BAT were decreased in the recovered rats. The thermogenic capacity of the BAT was not affected by the soyabean diet. The lipogenesis rate in the retroperitoneal WAT was similar in all of the groups except for the LL group, which had exacerbated lipogenesis. The enhancement of the lipolysis rate by isoproterenol was decreased in white adipocytes from the soyabean-recovered rats and was elevated in adipocytes from the soyabean-control rats. Thus, in animals maintained on a soyabean diet, the proportions of fat deposits are determined by the lipolysis rate, which differs depending on the previous nutritional status. Key words: Nutritional recovery: Soyabean diet: Adipose tissue: RatsSoya-containing diets have been shown to alter several parameters involved in maintaining body homeostasis, energy expenditure and feeding behaviour (1 -3) . Soya protein and isoflavone have been reported to reduce fat-pad weight by increasing uncoupling protein 1 (UCP-1) expression in brown adipose tissue (BAT) (4) . UCP-1 is a molecule that uncouples mitochondrial oxidative phosphorylation by bypassing the electrochemical gradient across the inner membrane from * Corresponding author: M. S. F. Martins, fax þ55 65 3615 8811, email msfm.cba@gmail.com Abbreviations: BAT, brown adipose tissue; C, control; CC, offspring born to and suckled by mothers fed a control diet that were fed a control diet after weaning; CS, offspring born to and suckled by mothers fed a control diet that were fed a soyabean diet with 17 % protein after weaning; HOMA-IR, homeostasis model assessment of insulin resistance; LC, offspring of mothers fed a low-protein diet that were fed a control diet after weaning; LL, offspring of mothers fed a low-protein diet that were fed a low-protein diet after weaning; LP, low-protein; LS, offspring of mothers fed a low-protein diet that were fed a soyabean diet containing 17 % protein after weaning; RWAT, retroperitoneal white adipose tissue; Tris, 2-amino-2-hydroxymethyl-propane-1,3-diol; UCP-1, uncoupling protein 1; WAT, white adipose tissue.

Nutritional recovery withokaradiet prevented hypercholesterolemia, hepatic steatosis and glucose intolerance

“…The proportions of fat deposits were determined by the lipolysis rate, which differed depending on the previous nutritional status. However, for rats subjected to protein restriction in early life, the soybean flour diet produced low lipolysis rate, whereas for the offspring from control rats the soybean flour diet resulted in high lipolysis rate (Paiva et al, 2012). In the present study, it is reasonable to suggest that the low protein diet during lactation superimposed on intrauterine protein restriction can have protected of increase adiposity in the adulthood.…”

Nutritional Recovery with a Soybean Diet after Weaning Reduces Lipogenesis but Induces Inflammation in the Liver in Adult Rats Exposed to Protein Restriction during Intrauterine Life and Lactation

“…Interestingly, we observed that serum insulin concentrations were increased in animals reared on a soybean diet, but alterations occurred in the early steps of the hepatic insulin signal transduction pathway, indicating hepatic insulin resistance [ 23 , 24 ]. Moreover, the weight and lipid content of the white adipose tissue as well as the lipolysis rate by isoproterenol in white adipocytes were decreased in rats fed the soybean diet [ 25 ]. Thus, the aim of this study was to investigate the effects of nutritional recovery after weaning with a soybean flour diet on de novo hepatic lipogenesis and inflammation in adult rats exposed to protein restriction during intrauterine life and lactation.…”