Beneficial effects of kinin B1 receptor antagonism on plasma fatty acid alterations and obesity in Zucker diabetic fatty rats

2016 ◽  
Vol 94 (7) ◽  
pp. 752-757 ◽  
Author(s):  
Sébastien Talbot ◽  
Jenny Pena Dias ◽  
Adil El Midaoui ◽  
Réjean Couture

Kinins are the endogenous ligands of the constitutive B2 receptor (B2R) and the inducible B1 receptor (B1R). Whereas B2R prevents insulin resistance, B1R is involved in insulin resistance and metabolic syndrome. However, the contribution of B1R in type 2 diabetes associated with obesity remains uncertain. The aim of the present study was to examine the impact of 1-week treatment with a selective B1R antagonist (SSR240612, 10 mg/kg per day, by gavage) on hyperglycemia, hyperinsulinemia, leptinemia, body mass gain, and abnormal plasma fatty acids in obese Zucker diabetic fatty (ZDF) rats. Treatment with SSR240612 abolished the body mass gain and reduced polyphagia, polydipsia, and plasma fatty acid alterations in ZDF rats without affecting hyperglycemia, hyperinsulinemia, and hyperleptinemia. The present study suggests that the upregulated B1R plays a role in body mass gain and circulating fatty acid alterations in ZDF rats. However, mechanisms other than B1R induction would be implicated in glucose metabolism disorder in ZDF rats, based on the finding that SSR240612 did not reverse hyperglycemia and hyperinsulinemia.

Author(s):  
Keisuke Fukumura ◽  
Kenshiro Shikano ◽  
Yuaki Narimatsu ◽  
Eiko Iwakoshi-Ukena ◽  
Megumi Furumitsu ◽  
...  

Abstract We recently identified a novel hypothalamic small protein, named neurosecretory protein GL (NPGL), which is involved in energy homeostasis in birds and mammals. However, whether the action of NPGL is influenced by nutritional composition remains unknown. Thus, we investigated the effect of chronic intracerebroventricular infusion of NPGL for 13 days on feeding behavior and body mass gain under a normal chow diet (NC), high-fat diet, high-sucrose diet (HSD), and medium-fat/medium-sucrose diet (MFSD) in rats. NPGL stimulated food intake of NC and MFSD, especially during the light period. By contrast, NPGL decreased body mass gain under NC and increased total white adipose tissue mass in HSD- and MFSD-fed rats. These data suggest that the effects of NPGL on feeding behavior, body mass gain, and fat accumulation depend on nutrient type. Among them, sucrose in diets seems to contribute to fat accumulation elicited by NPGL.


2015 ◽  
Vol 112 (4) ◽  
pp. 1143-1148 ◽  
Author(s):  
Daniel F. Vatner ◽  
Sachin K. Majumdar ◽  
Naoki Kumashiro ◽  
Max C. Petersen ◽  
Yasmeen Rahimi ◽  
...  

A central paradox in type 2 diabetes is the apparent selective nature of hepatic insulin resistance—wherein insulin fails to suppress hepatic glucose production yet continues to stimulate lipogenesis, resulting in hyperglycemia, hyperlipidemia, and hepatic steatosis. Although efforts to explain this have focused on finding a branch point in insulin signaling where hepatic glucose and lipid metabolism diverge, we hypothesized that hepatic triglyceride synthesis could be driven by substrate, independent of changes in hepatic insulin signaling. We tested this hypothesis in rats by infusing [U-13C] palmitate to measure rates of fatty acid esterification into hepatic triglyceride while varying plasma fatty acid and insulin concentrations independently. These experiments were performed in normal rats, high fat-fed insulin-resistant rats, and insulin receptor 2′-O-methoxyethyl chimeric antisense oligonucleotide-treated rats. Rates of fatty acid esterification into hepatic triglyceride were found to be dependent on plasma fatty acid infusion rates, independent of changes in plasma insulin concentrations and independent of hepatocellular insulin signaling. Taken together, these results obviate a paradox of selective insulin resistance, because the major source of hepatic lipid synthesis, esterification of preformed fatty acids, is primarily dependent on substrate delivery and largely independent of hepatic insulin action.


2005 ◽  
Vol 34 (2) ◽  
pp. 299-315 ◽  
Author(s):  
Young Ho Suh ◽  
Younyoung Kim ◽  
Jeong Hyun Bang ◽  
Kyoung Suk Choi ◽  
June Woo Lee ◽  
...  

Insulin resistance occurs early in the disease process, preceding the development of type 2 diabetes. Therefore, the identification of molecules that contribute to insulin resistance and leading up to type 2 diabetes is important to elucidate the molecular pathogenesis of the disease. To this end, we characterized gene expression profiles from insulin-sensitive tissues, including adipose tissue, skeletal muscle, and liver tissue of Zucker diabetic fatty (ZDF) rats, a well characterized type 2 diabetes animal model. Gene expression profiles from ZDF rats at 6 weeks (pre-diabetes), 12 weeks (diabetes), and 20 weeks (late-stage diabetes) were compared with age- and sex-matched Zucker lean control (ZLC) rats using 5000 cDNA chips. Differentially regulated genes demonstrating > 1.3-fold change at age were identified and categorized through hierarchical clustering analysis. Our results showed that while expression of lipolytic genes was elevated in adipose tissue of diabetic ZDF rats at 12 weeks of age, expression of lipogenic genes was decreased in liver but increased in skeletal muscle of 12 week old diabetic ZDF rats. These results suggest that impairment of hepatic lipogenesis accompanied with the reduced lipogenesis of adipose tissue may contribute to development of diabetes in ZDF rats by increasing lipogenesis in skeletal muscle. Moreover, expression of antioxidant defense genes was decreased in the liver of 12-week old diabetic ZDF rats as well as in the adipose tissue of ZDF rats both at 6 and 12 weeks of age. Cytochrome P450 (CYP) genes were also significantly reduced in 12 week old diabetic liver of ZDF rats. Genes involved in glucose utilization were downregulated in skeletal muscle of diabetic ZDF rats, and the hepatic gluconeogenic gene was upregulated in diabetic ZDF rats. Genes commonly expressed in all three tissue types were also observed. These profilings might provide better fundamental understanding of insulin resistance and development of type 2 diabetes.


Circulation ◽  
2018 ◽  
Vol 138 (Suppl_2) ◽  
Author(s):  
Claudius Balzer ◽  
Franz Baudenbacher ◽  
Michele M Salzman ◽  
William J Cleveland ◽  
Susan Eagle ◽  
...  

Patients with metabolic syndrome are at higher risk for cardiac arrest (CA), and also have worse neurologic outcome after CA related to their comorbidities (e.g., Type 2 Diabetes Mellitus [T2DM]). Using Zucker Diabetic Fatty (ZDF) rats as a new and relevant model with common comorbidities for CA and cardiopulmonary resuscitation (CPR), we hypothesized that T2DM is associated with a lower chance for return of spontaneous circulation (ROSC) and/or a worse outcome regarding heart function after asphyxial CA compared to their lean littermates. Two groups of rats (8 ZDF, 7 lean) were monitored for 37±2 weeks. The rats were anesthetized and intubated; heart rate was monitored by subcutaneous ECG needles. Femoral artery and vein were cannulated for continuous blood pressure measurement and delivery of fluids and medications, respectively. Before ventilation was stopped to initiate asphyxial CA, rocuronium was given. After 8 minutes of CA, ventilation was re-initiated with FiO 2 1.0, epinephrine and sodium-bicarbonate were administered, and pneumatic chest compression were started with 200 compressions per minute. Chest compressions were stopped when a systolic blood pressure of 120 mmHg was achieved. During 4 hours of observation, vital parameters were closely monitored, blood gases were measured, and ejection fraction (EF %) was assessed with ultrasound. Data are mean ± SD. Statistics: Unpaired student’s t-test (two-tailed), α.05. At baseline, ZDF rats showed significantly higher blood glucose levels (504±52 vs 174±14 mg/dl) compared to their lean littermates. All ZDF and lean rats achieved ROSC, and measurements taken directly after ROSC and after the first hour showed no relevant differences. After four hours, there was no difference in heart rate between ZDF and lean rats. However, diabetic rats had a significantly higher mean arterial blood pressure (142±24vs. 107±19 mmHg) and ejection fraction (42±16%vs 20±8%) compared to their lean littermates. The hypothesis that ROSC-rate in diabetic rats would be lower could not be proven. Conversely, the ZDF rats showed a significantly higher blood pressure related to an increased EF%. Further analysis in this study will focus on the impact of T2DM on cardiac and neurological ischemia-reperfusion injury.


2013 ◽  
Vol 38 (6) ◽  
pp. 621-625 ◽  
Author(s):  
Vahur Ööpik ◽  
Saima Timpmann ◽  
Andres Burk ◽  
Innar Hannus

We assessed the urinary indexes of hydration status of Greco-Roman wrestlers in an authentic precompetition situation at the time of official weigh-in (OWI). A total of 51 of 89 wrestlers competing in the Estonian Championship in 2009 donated a urine sample. Questionnaire responses revealed that 27 wrestlers (body mass losers (BMLs)) reduced body mass before the competition, whereas 24 wrestlers (those who do not lose body mass (n-BMLs)) did not. In 42 wrestlers, values of urine specific gravity ≥1.020 and urine osmolality ≥700 mOsmol·kg−1 revealed a hypohydrated status. The prevalence of hypohydration in the BMLs (96%) was higher than in the n-BMLs (67%) (χ2 = 7.68; p < 0.05). The prevalence of serious hypohydration (urine specific gravity >1.030) was 5.3 times greater (χ2 = 8.32; p < 0.05) in the BMLs than in the n-BMLs. In the BMLs, the extent of body mass gain during the 16-h recovery (2.5 ± 1.2 kg) was associated (r = 0.764; p < 0.05) with self-reported precompetition body mass loss (4.3 ± 2.0 kg) and exceeded the body mass gain observed in the n-BMLs (0.7 ± 1.2 kg; p < 0.05). We conclude that hypohydration is prevalent among Greco-Roman wrestlers at the time of OWI. The prevalence of hypohydration and serious hypohydration is especially high among wrestlers who are accustomed to reducing body mass before competition. These results suggest that an effective rehydration strategy is needed for Olympic-style wrestlers, and that changes in wrestling rules should be considered to reduce the prevalence of harmful body mass management behaviours.


2003 ◽  
Vol 284 (5) ◽  
pp. E892-E900 ◽  
Author(s):  
Erik J. Henriksen ◽  
Tyson R. Kinnick ◽  
Mary K. Teachey ◽  
Matthew P. O'Keefe ◽  
David Ring ◽  
...  

A role for elevated glycogen synthase kinase-3 (GSK-3) activity in the multifactorial etiology of insulin resistance is now emerging. However, the utility of specific GSK-3 inhibition in modulating insulin resistance of skeletal muscle glucose transport is not yet fully understood. Therefore, we assessed the effects of novel, selective organic inhibitors of GSK-3 (CT-98014 and CT-98023) on glucose transport in insulin-resistant muscles of Zucker diabetic fatty (ZDF) rats. Incubation of type IIb epitrochlearis and type I soleus muscles from ZDF rats with CT-98014 increased glycogen synthase activity (49 and 50%, respectively, P < 0.05) but did not alter basal glucose transport (2-deoxyglucose uptake). In contrast, CT-98014 significantly increased the stimulatory effects of both submaximal and maximal insulin concentrations in epitrochlearis (37 and 24%) and soleus (43 and 26%), and these effects were associated with increased cell-surface GLUT4 protein. Lithium enhanced glycogen synthase activity and both basal and insulin-stimulated glucose transport in muscles from ZDF rats. Acute oral administration (2 × 30 mg/kg) of CT-98023 to ZDF rats caused elevations in GSK-3 inhibitor concentrations in plasma and muscle. The glucose and insulin responses during a subsequent oral glucose tolerance test were reduced by 26 and 34%, respectively, in the GSK-3 inhibitor-treated animals. Thirty minutes after the final GSK-3 inhibitor treatment, insulin-stimulated glucose transport was significantly enhanced in epitrochlearis (57%) and soleus (43%). Two hours after the final treatment, insulin-mediated glucose transport was still significantly elevated (26%) only in the soleus. These results indicate that specific inhibition of GSK-3 enhances insulin action on glucose transport in skeletal muscle of the insulin-resistant ZDF rat. This unique approach may hold promise as a pharmacological treatment against insulin resistance of skeletal muscle glucose disposal.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Guilherme L. da Rocha ◽  
Alex H. Crisp ◽  
Maria R. M. de Oliveira ◽  
Carlos A. da Silva ◽  
Jadson O. Silva ◽  
...  

This study aimed to investigate the effects of interval and continuous training on the body mass gain and adiposity levels of rats fed a high-fat diet. Forty-eight male Sprague-Dawley rats were randomly divided into two groups, standard diet and high-fat diet, and received their respective diets for a period of four weeks without exercise stimuli. After this period, the animals were randomly divided into six groups (n=8): control standard diet (CS), control high-fat diet (CH), continuous training standard diet (CTS), continuous training high-fat diet (CTH), interval training standard diet (ITS), and interval training high-fat diet (ITH). The interval and continuous training consisted of a swimming exercise performed over eight weeks. CH rats had greater body mass gain, sum of adipose tissues mass, and lower serum high density lipoprotein values than CS. The trained groups showed lower values of feed intake, caloric intake, body mass gain, and adiposity levels compared with the CH group. No significant differences were observed between the trained groups (CTS versus ITS and CTH versus ITH) on body mass gains and adiposity levels. In conclusion, both training methodologies were shown to be effective in controlling body mass gain and adiposity levels in high-fat diet fed rats.


2014 ◽  
Vol 221 (3) ◽  
pp. 415-427 ◽  
Author(s):  
Alvaro Souto Padron ◽  
Ruy Andrade Louzada Neto ◽  
Thiago Urgal Pantaleão ◽  
Maria Carolina de Souza dos Santos ◽  
Renata Lopes Araujo ◽  
...  

In general, 3,5-diiodothyronine (3,5-T2) increases the resting metabolic rate and oxygen consumption, exerting short-term beneficial metabolic effects on rats subjected to a high-fat diet. Our aim was to evaluate the effects of chronic 3,5-T2 administration on the hypothalamus–pituitary–thyroid axis, body mass gain, adipose tissue mass, and body oxygen consumption in Wistar rats from 3 to 6 months of age. The rats were treated daily with 3,5-T2 (25, 50, or 75 μg/100 g body weight, s.c.) for 90 days between the ages of 3 and 6 months. The administration of 3,5-T2 suppressed thyroid function, reducing not only thyroid iodide uptake but also thyroperoxidase, NADPH oxidase 4 (NOX4), and thyroid type 1 iodothyronine deiodinase (D1 (DIO1)) activities and expression levels, whereas the expression of the TSH receptor and dual oxidase (DUOX) were increased. Serum TSH, 3,3′,5-triiodothyronine, and thyroxine were reduced in a 3,5-T2 dose-dependent manner, whereas oxygen consumption increased in these animals, indicating the direct action of 3,5-T2 on this physiological variable. Type 2 deiodinase activity increased in both the hypothalamus and the pituitary, and D1 activities in the liver and kidney were also increased in groups treated with 3,5-T2. Moreover, after 3 months of 3,5-T2 administration, body mass and retroperitoneal fat pad mass were significantly reduced, whereas the heart rate and mass were unchanged. Thus, 3,5-T2 acts as a direct stimulator of energy expenditure and reduces body mass gain; however, TSH suppression may develop secondary to 3,5-T2 administration.


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