Obese Rats
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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Paulina M. Opyd ◽  
Adam Jurgoński

AbstractWe hypothesized that milk thistle seed or seed oil dietary supplementation reduces intestinal, liver and lipid disorders specific to genetic obesity, and the seeds can be more efficient in doing so. Lean and obese male Zucker rats were allocated to 4 groups: the lean (LC) and obese control (OC) groups fed a standard diet and the other 2 obese groups fed a diet supplemented with milk thistle seed oil (O + MTO) or milk thistle seeds (O + MTS). After 5 weeks of feeding, the cecal SCFA pool was slightly and significantly lower in OC and O + MTO compared with LC and O + MTS. The liver fat content was greater in OC, O + MTO and O + MTS compared with LC; however, it was significantly lower in O + MTS than in OC and O + MTO. The plasma cholesterol was greater in OC compared with LC, O + MTO and O + MTS; however, it was significantly greater in O + MTO and O + MTS compared with LC. The plasma bilirubin was detected in OC and O + MTO, whereas it was not present in LC and O + MTS. Milk thistle seeds can improve fermentation events in the distal intestine and reduce other disorders specific to genetically obese rats, and the seed PUFAs are responsible for that to a lesser extent.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shaymaa Abdulmalek ◽  
Asmaa Eldala ◽  
Doaa Awad ◽  
Mahmoud Balbaa

AbstractThe present study was carried out to investigate the therapeutic effect of synthesized naturally compounds, curcumin nanoparticles (CurNPs) and metal oxide, zinc oxide nanoparticles (ZnONPs) on a high-fat diet (HFD)/streptozotocin (STZ)-induced hepatic and pancreatic pathophysiology in type 2 diabetes mellitus (T2DM) via measuring AKT pathway and MAPK pathway. T2DM rats were intraperitoneally injected with a low dose of 35 mg/kg STZ after being fed by HFD for 8 weeks. Then the rats have orally received treatments for 6 weeks. HFD/STZ-induced hepatic inflammation, reflected by increased phosphorylation of p38-MAPK pathway’s molecules, was significantly decreased after nanoparticle supplementation. In addition, both nanoparticles significantly alleviated the decreased phosphorylation of AKT pathway. Further, administration of ZnONPs, CurNPs, conventional curcumin, and ZnSO4 (zinc sulfate), as well as metformin, effectively counteracted diabetes-induced oxidative stress and inflammation in the internal hepatic and pancreatic tissues. Based on the results of the current study, ZnONPs and CurNPs could be explored as a therapeutic adjuvant against complications associated with T2DM. Both nanoparticles could effectively delay the progression of several complications by activating AKT pathway and down-regulating MAPK pathway. Our findings may provide an experimental basis for the application of nanoparticles in the treatment of T2DM with low toxicity.


2021 ◽  
Author(s):  
Elizabeth A Wellberg ◽  
Karen A Corleto ◽  
L. Allyson Checkley ◽  
Sonali Jindal ◽  
Ginger Johnson ◽  
...  

Obesity and adult weight gain are linked to increased breast cancer risk and poorer clinical outcomes in postmenopausal women, particularly for hormone-dependent tumors. Menopause is a time when significant weight gain occurs in many women, and clinical and preclinical studies have identified menopause (or ovariectomy) as a period of vulnerability for breast cancer development and promotion. We hypothesized that preventing weight gain after ovariectomy (OVX) may be sufficient to prevent the formation of new tumors and decrease growth of existing mammary tumors. Here, we tested this hypothesis in a rat model of obesity and carcinogen-induced postmenopausal mammary cancer and validated our findings in a murine xenograft model with implanted human tumors. In both models, preventing weight gain after OVX significantly decreased obesity-associated tumor development and growth. Importantly, we did not induce weight loss in these animals, but simply prevented weight gain. In both lean and obese rats, preventing weight gain reduced visceral fat accumulation and associated insulin resistance. Similarly, the intervention decreased circulating tumor-promoting growth factors and inflammatory cytokines (ie, BNDF, TNFα, FGF2), with greater effects in obese compared to lean rats. In obese rats, preventing weight gain decreased adipocyte size, adipose tissue macrophage infiltration, reduced expression of the tumor-promoting growth factor FGF-1, and reduced phosphorylated FGFR in tumors. Together, these findings suggest that the underlying mechanisms associated with the anti-tumor effects of weight maintenance are multi-factorial, and that weight maintenance during the peri-/post-menopausal period may be a viable strategy for reducing obesity-associated breast cancer risk and progression in women.


Author(s):  
Ruben Rodriguez ◽  
Andrew Y Lee ◽  
Jose A Godoy-Lugo ◽  
Bridget Martinez ◽  
Hiroyuki Ohsaki ◽  
...  

Inappropriate activation of the renin-angiotensin system decreases glucose uptake in peripheral tissues. Chronic angiotensin receptor type 1 (AT1) blockade increases glucose uptake in skeletal muscle, decreases the abundance of large adipocytes, and macrophage infiltration in adipose. However, the contributions of each tissue to the improvement in hyperglycemia in response to AT1 blockade are not known. Therefore, we determined the static and dynamic responses of soleus muscle, liver, and adipose to an acute glucose challenge following the chronic blockade of AT1. We measured adipocyte morphology along with TNF-α expression, F4/80 and CD11c positive cells in adipose and measured insulin receptor (IR) phosphorylation and AKT phosphorylation in soleus muscle, liver, and retroperitoneal fat before (T0), 60 (T60), and 120 (T120) minutes after an acute glucose challenge in the following groups of male rats: LETO (lean control; n = 5/time point), (2) obese OLETF (n = 7-8/time point) and (3) OLETF + ARB (ARB; 10 mg olmesartan/kg/d; n = 7-8/time point). AT1 blockade decreased adipocyte TNF-α expression and F4/80 and CD11c positive cells. In retroperitoneal fat at T60, IR phosphorylation was 155% greater in ARB than in OLETF. Furthermore, in retroperitoneal fat AT1 blockade increased GLUT4 protein expression in ARB compared to OLETF. IR phosphorylation and AKT phosphorylation were not altered in the liver of OLETF, but AT1 blockade decreased hepatic PCK1 and G6PC1 mRNA expressions. Collectively, these results suggest that chronic AT1 blockade improves obesity-associated hyperglycemia in OLETF rats by improving adipocyte function and by decreasing hepatic glucose production via gluconeogenesis.


Cells ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2733
Author(s):  
Catherine M Pastor ◽  
Valérie Vilgrain

Fat accumulation (steatosis) in ballooned hepatocytes alters the expression of membrane transporters in Zucker fatty (fa/fa) rats. The aim of the study was to quantify the functions of these transporters and their impact on hepatocyte concentrations using a clinical hepatobiliary contrast agent (Gadobenate dimeglumine, BOPTA) for liver imaging. In isolated and perfused rat livers, we quantified BOPTA accumulation and decay profiles in fa/+ (normal) and fa/fa hepatocytes by placing a gamma counter over livers. Profiles of BOPTA accumulation and decay in hepatocytes were analysed with nonlinear regressions to characterise BOPTA influx and efflux across hepatocyte transporters. At the end of the accumulation period, BOPTA hepatocyte concentrations and influx clearances were not significantly different in fa/+ and fa/fa livers. In contrast, bile clearance was significantly lower in fatty hepatocytes while efflux clearance back to sinusoids compensated the low efflux into canaliculi. The time when BOPTA cellular efflux impacts the accumulation profile of hepatocyte concentrations was slightly delayed (2 min) by steatosis, anticipating a delayed emptying of hepatocytes. The experimental model is useful for quantifying the functions of hepatocyte transporters in liver diseases.


Author(s):  
Jéssica Leite Garcia ◽  
Danielle Fernandes Vileigas ◽  
Cristina Schmitt Gregolin ◽  
Mariane Róvero Costa ◽  
Fabiane Valentini Francisqueti-Ferron ◽  
...  

Abstract Purpose This study aimed to evaluate the effect of rice bran (RB) supplementation to a high-sugar fat (HSF) diet on cardiac dysfunction in an experimental obesity model. Methods Male Wistar rats were distributed into three groups: control, high-sugar fat, and high-sugar fat supplemented with 11% RB for 20 weeks. Results HSF diet promoted obesity and metabolic complications. Obese rats showed cardiac structural and functional impairment associated with high levels of interleukin-6, tumoral necrosis factor alpha, and malondialdehyde, and decreased activity of superoxide dismutase and catalase in the myocardium. RB supplementation was able to mitigate obesity and its metabolic alterations in HSF diet-fed animals. Moreover, the RB also prevented structural and functional damage, inflammation, and redox imbalance in the heart of these animals. Conclusion This study suggests that RB supplementation prevents cardiac dysfunction in rats fed on HSF by modulating systemic metabolic complications and inflammation and oxidative stress in the myocardium, representing potential alternative therapy.


2021 ◽  
pp. e00994
Author(s):  
OGUNYEMI BUKOLA CAROLINE ◽  
A.T. EBUEHI OSARETIN ◽  
OSHANUPIN ADEOLA CECILIA ◽  
OGUNYEMI ADEWALE KAYODE

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
G Tian ◽  
L Liu ◽  
C D Luo ◽  
M Li ◽  
L F Cao ◽  
...  

Abstract Background and aims Epicardial adipose tissue (EAT)-derived leptin contributes to myocardial remodeling in metabolic syndrome. However, the precise mechanisms remain to be determined. The present study was designed to elucidate the adverse effects of EAT-derived leptin on obesity-related myocardial remodeling. Methods and results Eight-week-old male Wistar rats were divided into two groups that received either a normal diet (control, n=10) or a high-fat diet (obese, n=10) for 12 weeks. Obese rats exhibited abnormal myocardial structure, diastolic dysfunction and abundant collagen deposition. Local leptin expression in obese rats EAT upregulated along with adipocyte hypertrophy, accompanied by renin-angiotensin-aldosterone system (RAAS) activation and increased oxidative stress level. Leptin receptor (ObR) and angiotensin II type 1 receptor (AT1R) expression in obese EAT were significantly higher than that in control. In vitro, mature adipocytes treated with angiotensin II (Ang II) exhibited pronounced leptin synthesis and secretion by promoting AP-1 nuclear translocation via the AT1R-ROS-ERK1/2 pathway. Moreover, cardiac fibroblasts were incubated with obese rat EAT-conditioned medium (EAT-CM), plus various inhibitors. EAT-derived leptin promoted proliferation of cardiac fibroblasts associated with increased ERK1/2 phosphorylation and induced MMPs/TIMPs imbalance, stimulating upregulation of type I collagen via the JAK2/STAT3-TGF-β1/Smad3 pathway in cardiac fibroblasts of obese rats. Conclusions The paracrine effect of EAT-derived leptin on myocardial remodeling, inducing MMPs/TIMPs imbalance and promoting the proliferation of cardiac fibroblasts via activating ERK1/2 and JAK2/STAT3-TGF-β1/Smad3 pathway in obesity. FUNDunding Acknowledgement Type of funding sources: Foundation. Main funding source(s): the Nature Science Foundation of China (grant no. 81873513, 81600574, and 30871042)


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