scholarly journals 1-Sarcosine-angiotensin II infusion effects on food intake, weight loss, energy expenditure, and skeletal muscle UCP3 gene expression in a rat model

2014 ◽  
Vol 5 (3) ◽  
pp. 239-246 ◽  
Author(s):  
S. A. Cichello ◽  
R. S. Weisinger ◽  
J. Schuijers ◽  
M. Jois
2017 ◽  
Vol 313 (6) ◽  
pp. E731-E736 ◽  
Author(s):  
Wenjuan Wang ◽  
Xiangzhi Meng ◽  
Chun Yang ◽  
Dongliang Fang ◽  
Xuemeng Wang ◽  
...  

Loss of body weight and fat mass is one of the nonmotor symptoms of Parkinson’s disease (PD). Weight loss is due primarily to reduced energy intake and increased energy expenditure. Whereas inadequate energy intake in PD patients is caused mainly by appetite loss and impaired gastrointestinal absorption, the underlying mechanisms for increased energy expenditure remain largely unknown. Brown adipose tissue (BAT), a key thermogenic tissue in humans and other mammals, plays an important role in thermoregulation and energy metabolism; however, it has not been tested whether BAT is involved in the negative energy balance in PD. Here, using the 6-hydroxydopamine (6-OHDA) rat model of PD, we found that the activity of sympathetic nerve (SN), the expression of Ucp1 in BAT, and thermogenesis were increased in PD rats. BAT sympathetic denervation blocked sympathetic activity and decreased UCP1 expression in BAT and attenuated the loss of body weight in PD rats. Interestingly, sympathetic denervation of BAT was associated with decreased sympathetic tone and lipolysis in retroperitoneal and epididymal white adipose tissue. Our data suggeste that BAT-mediated thermogenesis may contribute to weight loss in PD.


2021 ◽  
Author(s):  
Ada Admin ◽  
David M Presby ◽  
Michael C Rudolph ◽  
Vanessa D Sherk ◽  
Matthew R Jackman ◽  
...  

Moderate weight loss improves numerous risk factors for cardiometabolic disease; however, long-term weight loss maintenance (WLM) is often thwarted by metabolic adaptations that suppress energy expenditure and facilitate weight regain. Skeletal muscle has a prominent role in energy homeostasis; therefore, we investigated the effect of WLM and weight regain on skeletal muscle in rodents. In skeletal muscle of obesity-prone rats, WLM reduced fat oxidative capacity and downregulated genes involved in fat metabolism. Interestingly, even after weight was regained, genes involved in fat metabolism genes were also reduced. We then subjected mice with skeletal muscle lipoprotein lipase overexpression (mCK-hLPL), which augments fat metabolism, to WLM and weight regain and found that mCK-hLPL attenuates weight regain by potentiating energy expenditure. Irrespective of genotype, weight regain suppressed dietary fat oxidation and downregulated genes involved in fat metabolism in skeletal muscle. However, mCK-hLPL mice oxidized more fat throughout weight regain and had greater expression of genes involved in fat metabolism and lower expression of genes involved in carbohydrate metabolism during WLM and regain. In summary, these results suggest that skeletal muscle fat oxidation is reduced during WLM and regain, and therapies that improve skeletal muscle fat metabolism may attenuate rapid weight regain.


2018 ◽  
Vol 125 (5) ◽  
pp. 1536-1554 ◽  
Author(s):  
Mette Flindt Heisterberg ◽  
Jesper L. Andersen ◽  
Peter Schjerling ◽  
Alberte Lund ◽  
Simone Dalskov ◽  
...  

Our purpose here was to investigate the potential of blocking the angiotensin II type I receptor (AT1R) on the hypertrophy response of elderly human skeletal muscle to 4 mo of heavy-resistance exercise training. Fifty-eight healthy elderly men (+65 yr) were randomized into three groups, consuming either AT1R blocker (losartan, 100 mg/day) or placebo for 4 mo. Two groups performed resistance training (RT) and were treated with either losartan or placebo, and one group did not train but was treated with losartan. Quadriceps muscle biopsies, MR scans, and strength tests were performed at baseline and after 8 and 16 wk. Biopsies were sectioned for immunohistochemistry to determine the number of satellite cells, capillaries, fiber type distribution, and fiber area. Gene expression levels of myostatin, connective tissue, and myogenic signaling pathways were determined by real-time RT-PCR. Four months of heavy-resistance training led in both training groups to expected improvements in quadriceps (∼3–4%) and vastus lateralis (∼5–6%), cross-sectional area, and type II fiber area (∼10–18%), as well as dynamic (∼13%) and isometric (∼19%) quadriceps peak force, but with absolutely no effect of losartan on these outcomes. Furthermore, no changes were seen in satellite cell number with training, and most gene targets failed to show any changes induced by training or losartan treatment. We conclude that there does not appear to be any effect of AT1R blocking in elderly men during 4 mo of resistance training. Therefore, we do not find any support for using AT1R blockers for promoting muscle adaptation to training in humans. NEW & NOTEWORTHY Animal studies have suggested that blocking angiotensin II type I receptor (AT1R) enhances muscle regeneration and prevents disuse atrophy, but studies in humans are limited. Focusing on hypertrophy, satellite cells, and gene expression, we found that AT1R blocking did not result in any greater responses with 4 mo of resistance training. These results do not support previous findings and question the value of blocking AT1R in the context of preserving aging human muscle.


Author(s):  
Eric A. Wilson ◽  
Hui Sun ◽  
Zhenzhong Cui ◽  
Marshal T. Jahnke ◽  
Mritunjay Pandey ◽  
...  

The G protein subunits Gqα and G11α (Gq/11α) couple receptors to phospholipase C, leading to increased intracellular calcium. In this study we investigated the consequences of Gq/11α deficiency in the dorsomedial hypothalamus (DMH), a critical site for the control of energy homeostasis. Mice with DMH-specific deletion of Gq/11α (DMHGq/11KO) were generated by stereotaxic injection of AAV-Cre-GFP into the DMH of Gqαflox/flox:G11α-/- mice. Compared to control mice that received DMH injection of AAV-GFP, DMHGq/11KO mice developed obesity associated with reduced energy expenditure without significant changes in food intake or physical activity. DMHGq/11KO mice showed no defects in the ability of the melanocortin agonist melanotan II to acutely stimulate energy expenditure or to inhibit food intake. At room temperature (22oC) DMHGq/11KO mice showed reduced sympathetic nervous system activity in brown adipose tissue (BAT) and heart, accompanied with decreased basal BAT Ucp1 gene expression and lower heart rates. These mice were cold intolerant when acutely exposed to cold (6oC for 5 hours) and had decreased cold-stimulated BAT Ucp1 gene expression. DMHGq/11KO mice also failed to adapt to gradually declining ambient temperatures and to develop adipocyte browning in inguinal white adipose tissue although their BAT Ucp1 was proportionally stimulated. Consistent with impaired cold-induced thermogenesis, the onset of obesity in DMHGq/11KO mice was significantly delayed when housed under thermoneutral conditions (30ºC). Thus, our results show that Gqα and G11α in the DMH are required for the control of energy homeostasis by stimulating energy expenditure and thermoregulation.


FEBS Letters ◽  
1998 ◽  
Vol 436 (3) ◽  
pp. 415-418 ◽  
Author(s):  
Daniel Sanchı́s ◽  
Sı́lvia Busquets ◽  
Belén Alvarez ◽  
Daniel Ricquier ◽  
Francisco J López-Soriano ◽  
...  

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 9571-9571
Author(s):  
J. M. Brell ◽  
J. Hardacre ◽  
J. Schulak ◽  
R. Onders ◽  
T. Stellato ◽  
...  

9571 Background: Decreased body mass (cachexia) is a common cause of functional decline in pancreas carcinoma (PC) and other malignancies. The etiology is unknown. Characterization of human PC skeletal muscle, in regard to proteolysis and gene expression, compared to control muscle may reveal information about pathophysiology. Methods: Biopsies of rectus abdominus muscle were performed in weight-losing PC patients all stages (A) during cancer-related surgery and in cancer-free controls undergoing ventral hernia repair (B). Caspase-3, pAkt, and urinary 3-methylhistidine (u3-MH) were assessed by Western blot and high-performance liquid chromatography. Fat-free mass (FFM), body mass index (BMI), and time to progression were recorded. Muscle from five patients (median weight loss 21%) and five controls were analyzed for gene expression patterns using Affymetrix Human Genome U133 A 2.0 array chip. Two hundred differentially over- and under-expressed genes were examined in group A for potential association with cachexia. RT-PCR confirmation of six candidate genes was performed. Results: Thirty-eight patients were enrolled. Median weight loss in group A (N=27) was 14.5% (5% - 34%). No differences were noted between groups in caspase-3 and pAkt expression. Baseline u3-MH (p=0.86) and FFM (p= 0.28) did not differ; baseline BMI was lower in group A (p=0.04). BMI follow-up measurements (N=17) were significantly decreased (p=0.0005). In 65% patients, progressive disease was noted within median time of 3 months. RT-PCR established up-regulation of CHRNA1 and LMO7, but not GDF8. mRNA down-regulation for TRIM63, IGF-BP6, and MYH-1 was confirmed. Conclusions: Muscle proteolysis in human PC skeletal muscle was not demonstrated, perhaps due to unmeasurable proteolysis or use of non-informative endpoints. BMI decreased in group A with PD; further studies need tight control of BMI variables. New hypotheses about cachexia include neuromuscular junction dysfunction, as CHRNA1 has specific role in ion channel gating; this is disrupted in the paraneoplastic Eaton-Lambert syndrome. This is first study analyzing human muscle in weight-losing PC and proves symptom management multidisciplinary research is feasible in academic setting. Supported by American Cancer Society pilot grant. No significant financial relationships to disclose.


Nutrients ◽  
2016 ◽  
Vol 8 (11) ◽  
pp. 712 ◽  
Author(s):  
Andrea Marti ◽  
Peter Meerlo ◽  
Janne Grønli ◽  
Sjoerd van Hasselt ◽  
Jelena Mrdalj ◽  
...  

2005 ◽  
Vol 288 (1) ◽  
pp. E228-E235 ◽  
Author(s):  
Rocco Barazzoni ◽  
Alessandra Bosutti ◽  
Marco Stebel ◽  
Maria Rosa Cattin ◽  
Elena Roder ◽  
...  

Ghrelin is a gastric hormone increased during caloric restriction and fat depletion. A role of ghrelin in the regulation of lipid and energy metabolism is suggested by fat gain independent of changes in food intake during exogenous ghrelin administration in rodents. We investigated the potential effects of peripheral ghrelin administration (two times daily 200-ng sc injection for 4 days) on triglyceride content and mitochondrial and lipid metabolism gene expression in rat liver and muscles. Compared with vehicle, ghrelin increased body weight but not food intake and circulating insulin. In liver, ghrelin induced a lipogenic and glucogenic pattern of gene expression and increased triglyceride content while reducing activated (phosphorylated) stimulator of fatty acid oxidation, AMP-activated protein kinase (AMPK, all P < 0.05), with unchanged mitochondrial oxidative enzyme activities. In contrast, triglyceride content was reduced ( P < 0.05) after ghrelin administration in mixed (gastrocnemius) and unchanged in oxidative (soleus) muscle. In mixed muscle, ghrelin increased ( P < 0.05) mitochondrial oxidative enzyme activities independent of changes in expression of fat metabolism genes and phosphorylated AMPK. Expression of peroxisome proliferator-activated receptor-γ, the activation of which reduces muscle fat content, was selectively increased in mixed muscle where it paralleled changes in oxidative capacities ( P < 0.05). Thus ghrelin induces tissue-specific changes in mitochondrial and lipid metabolism gene expression and favors triglyceride deposition in liver over skeletal muscle. These novel effects of ghrelin in the regulation of lean tissue fat distribution and metabolism could contribute to metabolic adaptation to caloric restriction and loss of body fat.


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