Dietary fructose-related adiposity and glucocorticoid receptor function in visceral adipose tissue of female rats

Abstract

The results suggest that the 11βHSD1-mediated elevation of intracellular corticosterone may induce GR downregulation, which may be associated with failure of GR to stimulate lipolysis in fructose-fed female rats.

Fructose-enriched diet induces inflammation and reduces antioxidative defense in visceral adipose tissue of young female rats

“…Considering the NF-κB activation and elevated IL-1β expression in the VAT without insulin resistance in fructosefed animals together with the fact that IL-1β can induce insulin resistance in adipocytes [19], our work supports the stand that VAT inflammation represents one of the earliest metabolic perturbations upon fructose overconsumption. The absence of insulin resistance in the VAT further confirms our previously published data that VAT accumulation in young fructose-fed female rats is due to inhibited lipolysis [44]. Namely, in these animals, lipolysis is inhibited both by preserved insulin signaling, which is the major physiological suppressor of lipolysis, and by the absence of lipolytic actions of glucocorticoid receptor [44].…”

“…Though IL-1β was shown to induce TNFα expression in adipocytes [22], and elevated expression of TNFα Statistical significance of the difference between experimental groups (Student's t test): *P < 0.05 was described in adipose tissue of obese humans [55] and mice [56], it was not observed herein. Nevertheless, unaltered TNFα expression in the VAT of fructose-fed animals is in accordance with unaltered plasma FFA concentration and unaltered peroxisome proliferator-activated receptor γ (PPARγ) expression in VAT that we have previously reported in the same experimental animals [44]. Namely, TNFα increases circulating FFA levels in vivo and in vitro presumably by down-regulation of proteins involved in FFA trapping in adipocytes, resulting in reduced re-esterification of FFA, as reviewed in [57].…”

“…We propose that NF-κB-regulated IL-1β expression is facilitated by HSD1-driven homologous down-regulation of glucocorticoid receptor, since our previously published results obtained in the same experimental animals showed elevated HSD1 protein level and intracellular corticosterone, as well as a consequent down-regulation of glucocorticoid receptor expression and function in the VAT [44]. On the other hand, since IL-1β can induce HSD1 expression and activity in the adipose tissue [61], these events might contribute to further propagation of inflammation, closing a vicious cycle.…”

“…We have previously reported that young, fructosefed female rats developed increased adiposity that was accompanied with elevated expression of 11β hydroxysteroid dehydrogenase type 1 (HSD1) and reduced glucocorticoid receptor hormone-binding capacity and affinity in the VAT [44]. It is tempting to speculate that these changes stem from inflammation and disruption of antioxidative system that have been described in the states of increased adiposity and obesity.…”

Effects of Artemisia dracunculus Aqueous Extract on Blood Sugar, Serum Insulin, Triglyceride and Liver Enzymes in Fructose Drinking Water Male Rats

“…Unnecessary fructose intake, characteristic for modern diet loaded in polished sugar has been associated with the augmentation of metabolic syndrome [1]. Metabolic syndrome is described the group of character of quite a lot of metabolic abnormalities, based on hyperlipidemia, abdominal obesity and insulin resistance [2].…”