Alleviation of salt-induced exacerbation of cardiac, renal, and visceral fat pathology in rats with metabolic syndrome by surgical removal of subcutaneous fat

Abstract

Objectives Evidence suggests that visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) should be considered as distinct types of white fat. Although VAT plays a key role in metabolic syndrome (MetS), the role of subcutaneous adipose tissue (SAT) has been unclear. DahlS.Z- Lepr fa / Lepr fa (DS/obese) rats, an animal model of MetS, develop adipocyte hypertrophy and inflammation to similar extents in SAT and VAT. We have now investigated the effects of salt loading and SAT removal on cardiac, renal, and VAT pathology in DS/obese rats. Methods DS/obese rats were subjected to surgical removal of inguinal SAT or sham surgery at 8 weeks of age. They were provided with a 0.3% NaCl solution as drinking water or water alone for 4 weeks from 9 weeks of age. Results Salt loading exacerbated hypertension, insulin resistance, as well as left ventricular (LV) hypertrophy, inflammation, fibrosis, and diastolic dysfunction in DS/obese rats. It also reduced both SAT and VAT mass but aggravated inflammation only in VAT. Although SAT removal did not affect LV hypertrophy in salt-loaded DS/obese rats, it attenuated hypertension, insulin resistance, and LV injury as well as restored fat mass and alleviated inflammation and the downregulation of adiponectin gene expression in VAT. In addition, whereas salt loading worsened renal injury as well as upregulated the expression of renin–angiotensin-aldosterone system-related genes in the kidney, these effects were suppressed by removal of SAT. Conclusions SAT removal attenuated salt-induced exacerbation of MetS and LV and renal pathology in DS/obese rats. These beneficial effects of SAT removal are likely attributable, at least in part, to inhibition of both VAT and systemic inflammation.

Surgical ablation of whitened interscapular brown fat ameliorates cardiac pathology in salt‐loaded metabolic syndrome rats

“…Moreover, restraint stress further upregulated GR and 11β-HSD1 expression as well as further enhanced macrophage-related inflammatory responses in the heart and visceral WAT of DS/obese rats in a manner sensitive to propranolol. 15 Consistent with our recent result, 9 salt loading increased urinary excretion of norepinephrine as well as enhanced epididymal WAT and iBAT inflammation in these rats. As with restraint stress, the present results could thus be explained in part by the loss of a proinflammatory effect by iBATx of increased sympathetic and glucocorticoid activity in whitened iBAT of salt-loaded DS/obese rats.…”

“…8 Furthermore, surgical removal of subcutaneous (inguinal) WAT attenuated salt-induced exacerbation of MetS and cardiac and renal pathology in DS/obese rats. 9 The aim of the present study was to investigate the effects of salt loading and surgical removal of whitened iBAT on cardiac and adipose tissue pathology as well as on metabolism in DS/obese rats.…”

Valproic Acid-Like Compounds Enhance and Prolong the Radiotherapy Effect on Breast Cancer by Activating and Maintaining Anti-Tumor Immune Function

“…Sample from the DMBA-induced breast cancer was used as control sample, and the expression of the target gene of each group was compared. ΔΔC t = experimental group ΔC t − control group ΔC t , ΔC t = (average C t of the target gene of the control sample - average C t of the control sample GAPDH) ( 40 , 41 ). The primer sequences used in this study are listed in Table S1 .…”