1
|
Ismaeil A, Gero D, Boyle CN, Alceste D, Taha O, Spector AC, Lutz TA, Bueter M. Early Postoperative Exposure to High-Fat Diet Does Not Increase Long-Term Weight Loss or Fat Avoidance After Roux-en-Y Gastric Bypass in Rats. Front Nutr 2022; 9:834854. [PMID: 35495960 PMCID: PMC9044042 DOI: 10.3389/fnut.2022.834854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 03/02/2022] [Indexed: 11/29/2022] Open
Abstract
Background Bariatric surgery alters food preferences in rats and reportedly decreases desire to consume high-fat high-sugar food in humans. The aim of this study was to investigate whether early post-operative exposure to high-fat food could increase body weight loss after Roux-en-Y gastric bypass (RYGB) by triggering fat avoidance. Methods Male Wistar rats underwent either RYGB (n = 15) or sham-operations (n = 16). Preoperatively a standardized 4-choice cafeteria diet [dietary options: low-fat/low-sugar (LFLS), low-fat/high-sugar (LFHS), high-fat/low-sugar (HFLS), high-fat/high-sugar (HFHS)] was offered. First, each option was available for 4 days, thereafter rats were offered the 4 options simultaneously for 3 days preoperatively. Post-surgery, 8 rats in the RYGB- and 8 in the sham-group were exposed to a high-fat content diet (Oatmeal + 30% lard, OM+L) for 10 days, while 7 RYGB rats and 8 sham-rats received OM alone. From the 11th postoperative day, the 4-choice cafeteria diet was reintroduced for 55-days. The intake of all available food items, macronutrients and body weight changes were monitored over 8 weeks. Main outcomes were long-term body-weight and daily change in relative caloric intake during the postoperative cafeteria period compared to the preoperative cafeteria. Results During the first 12 days of postoperative cafeteria access, RYGB-rats exposed to OM+L had a higher mean caloric intake per day than RYGB rats exposed to OM alone (Δ10 kCal, Padj = 0.004), but this difference between the RYGB groups disappeared thereafter. Consequently, in the last 33 days of the postoperative cafeteria diet, the mean body weight of the RYGB+OM+L group was higher compared to RYGB+OM (Δ51 g, Padj < 0.001). RYGB rats, independently from the nutritional intervention, presented a progressive decrease in daily consumption of calories from fat and increased their daily energy intake mainly from non-sugar carbohydrates. No such differences were detected in sham-operated controls exposed to low- or high fat postoperative interventions. Conclusion A progressive decrease in daily fat intake over time was observed after RYGB, independently from the nutritional intervention. This finding confirms that macronutrient preferences undergo progressive changes over time after RYGB and supports the role of ingestive adaptation and learning. Early postoperative exposure to high-fat food failed to accentuate fat avoidance and did not lead to superior weight loss in the long-term.
Collapse
Affiliation(s)
- Aiman Ismaeil
- Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
- Department of General Surgery, Aswan University Hospital, Aswan, Egypt
| | - Daniel Gero
- Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
| | - Christina N. Boyle
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland
| | - Daniela Alceste
- Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
| | - Osama Taha
- Department of Plastic Surgery, Assiut University Hospital, Asyut, Egypt
| | - Alan C. Spector
- Program in Neuroscience, Department of Psychology, Florida State University, Tallahassee, FL, United States
| | - Thomas A. Lutz
- Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland
| | - Marco Bueter
- Department of Surgery and Transplantation, University Hospital Zurich, Zurich, Switzerland
- *Correspondence: Marco Bueter,
| |
Collapse
|
2
|
Blonde GD, Mathes CM, Inui T, Hamel EA, Price RK, Livingstone MBE, Le Roux CW, Spector AC. Oromotor and somatic taste reactivity during sucrose meals reveals internal state and stimulus palatability after gastric bypass in rats. Am J Physiol Regul Integr Comp Physiol 2022; 322:R204-R218. [PMID: 35043683 PMCID: PMC8858674 DOI: 10.1152/ajpregu.00285.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/07/2022] [Accepted: 01/12/2022] [Indexed: 11/22/2022]
Abstract
After Roux-en-Y gastric bypass (RYGB), rats consume less high-energy foods and fluids, though whether this reflects a concomitant change in palatability remains unclear. By measuring behavior during intraorally delivered liquid meals across days (1 water, 8 sucrose sessions), we showed that RYGB rats (RYGB, n = 8/sex) consumed less 1.0 M sucrose than their sham surgery counterparts (SHAM, n = 8 males, n = 11 females) but displayed similarly high levels of ingestive taste reactivity responses at the start of infusions. Relative to water, both groups increased intake of sucrose, and ingestive responses were dominated by tongue protrusions rather than mouth movements. Thus, RYGB animals still found sucrose palatable despite consuming less than the SHAM group. As the intraoral infusion progressed but before meal termination, aversive behavior remained low and both RYGB and SHAM animals showed fewer ingestive responses, predominantly mouth movements as opposed to tongue protrusions. This shift in responsiveness unrelated to surgical manipulation suggests negative alliesthesia, or a decreased palatability, as rats approach satiation. Notably, only in RYGB rats, across sessions, there was a striking emergence of aversive behavior immediately after the sucrose meal. Thus, although lower intake in RYGB rats seems independent of the hedonic taste properties of sucrose, taste reactivity behavior in these animals immediately after termination of a liquid meal appears to be influenced by postoral events and reflects a state of nimiety or excessive consumption. Measurement of taste reactivity behaviors during an intraorally delivered meal represents a promising way to make inferences about internal state in nonverbal preclinical models.
Collapse
Affiliation(s)
- Ginger D Blonde
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| | - Clare M Mathes
- Department of Neuroscience, Baldwin Wallace University, Berea, Ohio
| | - Tadashi Inui
- Department of Oral Physiology, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan
| | - Elizabeth A Hamel
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| | - Ruth K Price
- Nutrition Innovation Centre for Food and Health (NICHE), School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - M Barbara E Livingstone
- Nutrition Innovation Centre for Food and Health (NICHE), School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
| | - Carel W Le Roux
- Diabetes Complications Research Centre, Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland
| | - Alan C Spector
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| |
Collapse
|
3
|
Hyde KM, Blonde GD, Nisi AV, Spector AC. The Influence of Roux-en-Y Gastric Bypass and Diet on NaCl and Sucrose Taste Detection Thresholds and Number of Circumvallate and Fungiform Taste Buds in Female Rats. Nutrients 2022; 14:nu14040877. [PMID: 35215527 PMCID: PMC8880222 DOI: 10.3390/nu14040877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 02/09/2022] [Accepted: 02/15/2022] [Indexed: 11/16/2022] Open
Abstract
Roux-en-Y gastric bypass (RYGB) in rats attenuates preference for, and intake of, sugar solutions. Additionally, maintenance on a high-fat diet (HFD) reportedly alters behavioral responsiveness to sucrose in rodents in short-term drinking tests. Due to the fact that the behavioral tests to date rely on the hedonic value of the stimulus to drive responsiveness, we sought to determine whether taste detection thresholds to sucrose and NaCl are affected by these manipulations as measured in an operant two-response signal detection paradigm. Female rats were maintained on HFD or chow for 10 weeks, at which point animals received either RYGB or SHAM surgery followed by a gel-based diet and then powdered chow. Upon recovery, half of the rats that were previously on HFD were switched permanently to chow, and the other rats were maintained on their presurgical diets (n = 5–9/diet condition x surgery group for behavioral testing). The rats were then trained and tested in a gustometer. There was a significant interaction between diet condition and surgery on NaCl threshold that was attributable to a lower value in RYGB vs. SHAM rats in the HFD condition, but this failed to survive a Bonferroni correction. Importantly, there were no effects of diet condition or surgery on sucrose thresholds. Additionally, although recent evidence suggests that maintenance on HFD alters taste bud number in the circumvallate papillae (CV) of mice, in a subset of rats, we did not find that diet significantly influenced taste pores in the anterior tongue or CV of female rats. These results suggest that any changes in sucrose responsiveness in intake/preference or hedonically oriented tests in rats as a function of HFD maintenance or RYGB are not attributable to alterations in taste sensitivity.
Collapse
|
4
|
Blonde GD, Price RK, le Roux CW, Spector AC. Meal Patterns and Food Choices of Female Rats Fed a Cafeteria-Style Diet Are Altered by Gastric Bypass Surgery. Nutrients 2021; 13:3856. [PMID: 34836110 PMCID: PMC8623594 DOI: 10.3390/nu13113856] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/21/2021] [Accepted: 10/26/2021] [Indexed: 12/28/2022] Open
Abstract
After Roux-en-Y gastric bypass surgery (RYGB), rats tend to reduce consumption of high-sugar and/or high-fat foods over time. Here, we sought to investigate the behavioral mechanisms underlying these intake outcomes. Adult female rats were provided a cafeteria diet comprised of five palatable foodstuffs varying in sugar and fat content and intake was monitored continuously. Rats were then assigned to either RYGB, or one of two control (CTL) groups: sham surgery or a nonsurgical control group receiving the same prophylactic iron treatments as RYGB rats. Post-sur-gically, all rats consumed a large first meal of the cafeteria diet. After the first meal, RYGB rats reduced intake primarily by decreasing the meal sizes relative to CTL rats, ate meals more slowly, and displayed altered nycthemeral timing of intake yielding more daytime meals and fewer nighttime meals. Collectively, these meal patterns indicate that despite being motivated to consume a cafeteria diet after RYGB, rats rapidly learn to modify eating behaviors to consume foods more slowly across the entire day. RYGB rats also altered food preferences, but more slowly than the changes in meal patterns, and ate proportionally more energy from complex carbohydrates and protein and proportionally less fat. Overall, the pattern of results suggests that after RYGB rats quickly learn to adjust their size, eating rate, and distribution of meals without altering meal number and to shift their macronutrient intake away from fat; these changes appear to be more related to postingestive events than to a fundamental decline in the palatability of food choices.
Collapse
Affiliation(s)
- Ginger D. Blonde
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA;
| | - Ruth K. Price
- Nutrition Innovation Centre for Food and Health (NICHE), School of Biomedical Sciences, Ulster University, Coleraine BT52 1SA, UK;
| | - Carel W. le Roux
- Diabetes Complications Research Centre, Conway Institute, School of Medicine, University College Dublin, D04 V1W8 Dublin, Ireland;
| | - Alan C. Spector
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA;
| |
Collapse
|
5
|
Leptin Receptors Are Not Required for Roux-en-Y Gastric Bypass Surgery to Normalize Energy and Glucose Homeostasis in Rats. Nutrients 2021; 13:nu13051544. [PMID: 34064308 PMCID: PMC8147759 DOI: 10.3390/nu13051544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/29/2022] Open
Abstract
Sensitization to the adipokine leptin is a promising therapeutic strategy against obesity and its comorbidities and has been proposed to contribute to the lasting metabolic benefits of Roux-en-Y gastric bypass (RYGB) surgery. We formally tested this idea using Zucker fatty fa/fa rats as an established genetic model of obesity, glucose intolerance, and fatty liver due to leptin receptor deficiency. We show that the changes in body weight in these rats following RYGB largely overlaps with that of diet-induced obese Wistar rats with intact leptin receptors. Further, food intake and oral glucose tolerance were normalized in RYGB-treated Zucker fatty fa/fa rats to the levels of lean Zucker fatty fa/+ controls, in association with increased glucagon-like peptide 1 (GLP-1) and insulin release. In contrast, while fatty liver was also normalized in RYGB-treated Zucker fatty fa/fa rats, their circulating levels of the liver enzyme alanine aminotransferase (ALT) remained elevated at the level of obese Zucker fatty fa/fa controls. These findings suggest that the leptin system is not required for the normalization of energy and glucose homeostasis associated with RYGB, but that its potential contribution to the improvements in liver health postoperatively merits further investigation.
Collapse
|
6
|
Hyde KM, Blonde GD, Bueter M, le Roux CW, Spector AC. Gastric bypass in female rats lowers concentrated sugar solution intake and preference without affecting brief-access licking after long-term sugar exposure. Am J Physiol Regul Integr Comp Physiol 2020; 318:R870-R885. [PMID: 32083966 DOI: 10.1152/ajpregu.00240.2019] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In rodents, Roux-en-Y gastric bypass (RYGB) decreases intake of, and preference for, foods or fluids that are high in sugar. Whether these surgically induced changes are due to decreases in the palatability of sugar stimuli is controversial. We used RYGB and sham-operated (SHAM) female rats to test the influence of prolonged ingestive experience with sugar solutions on the motivational potency of these stimuli to drive licking in brief-access (BA) tests. In experiment 1, RYGB attenuated intake of, and caloric preference for, 0.3 M sucrose during five consecutive, 46-h two-bottle tests (TBTs; sucrose). A second series of TBTs (5 consecutive, 46-h tests) with 1.0 M sucrose revealed similar results, except fluid preference for 1.0 M sucrose also significantly decreased. Before, between, and after the two series of TBTs, two sessions of BA tests (30 min; 10-s trials) with an array of sucrose concentrations (0 and 0.01-1.0 M) were conducted. Concentration-dependent licking and overall trial initiation did not differ between surgical groups in any test. In a similar experimental design in a second cohort of female rats, 0.6 and 2.0 M glucose (isocaloric with sucrose concentrations in experiment 1) were used in the TBTs; 0 and 0.06-2.0 M glucose were used in the BA tests. Outcomes were similar to those for experiment 1, except RYGB rats initiated fewer trials during the BA tests. Although RYGB profoundly affected intake of, and caloric preference for, sugar solutions and, with high concentrations, fluid preference, RYGB never influenced the motivational potency of sucrose or glucose to drive concentration-dependent licking in BA tests.
Collapse
Affiliation(s)
- Kellie M Hyde
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| | - Ginger D Blonde
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| | - Marco Bueter
- Division of Visceral and Transplantation Surgery, Department of Surgery, University of Zürich, Zürich, Switzerland
| | - Carel W le Roux
- Diabetes Complications Research Centre, Conway Institute, School of Medicine, University College Dublin, Dublin, Ireland
| | - Alan C Spector
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida
| |
Collapse
|
7
|
Optimization of a Technique to Standardize the Rodent Roux-En-Y Gastric Bypass Model and Troubleshooting of Postoperative Failures. Obes Surg 2020; 29:1681-1689. [PMID: 30810973 DOI: 10.1007/s11695-019-03789-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Rodent models are required in studies on the mechanism of Roux-en-Y gastric bypass (RYGB). However, the construction of the model is hard, and there are various causes of death after surgery in rats. METHODS RYGB models with procedures containing a series of anatomic landmark were established in rats. Optimized procedures during surgery, possible complications after surgery, and corresponding solutions were studied. RESULTS With the introduction of perioperative nursing and optimized surgery procedures, less time-consuming surgeries were performed and higher survival rates were achieved. Trouble-shooting data based on death time points are listed and discussed for various causes of failure. CONCLUSIONS This study provides practical suggestions for investigators to perform RYGB surgery on rats. The troubleshooting suggestions will help operators to efficiently identify problems in their procedures.
Collapse
|
8
|
Bankoglu EE, Seyfried F, Arnold C, Soliman A, Jurowich C, Germer CT, Otto C, Stopper H. Reduction of DNA damage in peripheral lymphocytes of obese patients after bariatric surgery-mediated weight loss. Mutagenesis 2018; 33:61-67. [PMID: 29294093 DOI: 10.1093/mutage/gex040] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/23/2017] [Indexed: 12/20/2022] Open
Abstract
Obesity is associated with several detrimental health consequences, among them an increased risk for development of cancer, and an overall elevated mortality. Multiple factors like hyperinsulinemia, chronic microinflammation and oxidative stress may be involved. The comet assay has been proven to be very sensitive for detection of DNA damage and has been used to explore the relationship between overweight/obesity and DNA damage, but results are controversial. Very few investigations have been performed to correlate weight loss of obese individuals and possible reduction of DNA damage and these studies have not provided clear results. As currently, only surgical interventions (metabolic/bariatric surgery) enable substantial and sustained weight loss in the vast majority of morbidly obese patients, we analyzed whole blood samples of 56 subsequent patients prior, 6 and 12 months after bariatric surgery. No reduction of DNA damage was observed in comet assay analysis after 6 months despite efficient weight loss, but a significant reduction was observed 12 months after surgery. Concurrently, the ferric-reducing antioxidant power assay showed a significant reduction after 6 and 12 months. The level of oxidised glutathione and lipid peroxidation products were increased at 6 months but normalised at 12 months after surgery. As conclusion, a significant weight reduction in obese patients may help to diminish existing DNA damage besides improving many other health aspects in these patients.
Collapse
Affiliation(s)
- Ezgi Eyluel Bankoglu
- Institute of Pharmacology and Toxicology, University of Wuerzburg, Wuerzburg, Germany
| | - Florian Seyfried
- Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Charlotte Arnold
- Institute of Pharmacology and Toxicology, University of Wuerzburg, Wuerzburg, Germany
| | - Alexander Soliman
- Institute of Pharmacology and Toxicology, University of Wuerzburg, Wuerzburg, Germany
| | - Christian Jurowich
- Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Christoph Thomas Germer
- Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Christoph Otto
- Department of General, Visceral, Vascular and Paediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany.,Experimental Surgery, Department of General, Visceral, Vascular, and Pediatric Surgery, University Hospital of Wuerzburg, Wuerzburg, Germany
| | - Helga Stopper
- Institute of Pharmacology and Toxicology, University of Wuerzburg, Wuerzburg, Germany
| |
Collapse
|
9
|
Akalestou E, Genser L, Villa F, Christakis I, Chokshi S, Williams R, Rubino F. Establishing a successful rat model of duodenal- jejunal bypass: A detailed guide. Lab Anim 2018; 53:362-371. [PMID: 30227760 DOI: 10.1177/0023677218797370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Gastric bypass surgery, an operation that restricts the stomach and bypasses the duodenum and part of the jejunum, results in major improvement or remission of type 2 diabetes. Duodenual-jejunal bypass was developed by one of the authors (FR) as an experimental, stomach-sparing variant of gastric bypass surgery to investigate weight-independent mechanisms of surgical control of diabetes. Duodenual-jejunal bypass has been shown to improve various aspects of glucose homeostasis in rodents and in humans, thus providing an experimental model for investigating mechanisms of action of surgery and elusive aspects of gastrointestinal physiology. Performing duodenual-jejunal bypass in rodents, however, is associated with a steep learning curve. Here we report our experience with duodenual-jejunal bypass and provide practical tips for successful surgery in rats. Duodenual-jejunal bypass was performed on 50 lean rats as part of a study aimed at investigating the effect of the procedure on the physiologic mechanisms of glucose homeostasis. During the study, we have progressively refined details of anatomic exposure, technical aspects of duodeno-jejunostomy and peri-operative care. We analysed the role of such refinements in improving operative time and post-operative mortality. We found that refinement of exposure methods of the gastro-duodenal junction aimed at minimizing tension on small visceral vasculature, technical aspects of duodeno-jejunal anastomosis and peri-operative management played a major role in improving the survival rate and operative time. Overall, an experimental model of duodenual-jejunal bypass was successfully reproduced. Based on this experience, we describe here what we believe are the most important technical tips to reduce the learning curve for the procedure.
Collapse
Affiliation(s)
- Elina Akalestou
- 1 Division of Diabetes and Nutritional Sciences, King's College London, UK.,2 Institute of Hepatology London, Foundation for Liver Research, London, UK.,3 Division of Transplantation, Immunology and Mucosal Biology, Faculty of Life Sciences and Medicine, King's College London, UK
| | - Laurent Genser
- 1 Division of Diabetes and Nutritional Sciences, King's College London, UK.,4 Department of Surgery, King's College Hospital NHS Foundation Trust, London, UK
| | - Francesco Villa
- 1 Division of Diabetes and Nutritional Sciences, King's College London, UK.,4 Department of Surgery, King's College Hospital NHS Foundation Trust, London, UK
| | - Ioannis Christakis
- 4 Department of Surgery, King's College Hospital NHS Foundation Trust, London, UK
| | - Shilpa Chokshi
- 2 Institute of Hepatology London, Foundation for Liver Research, London, UK.,3 Division of Transplantation, Immunology and Mucosal Biology, Faculty of Life Sciences and Medicine, King's College London, UK
| | - Roger Williams
- 2 Institute of Hepatology London, Foundation for Liver Research, London, UK.,3 Division of Transplantation, Immunology and Mucosal Biology, Faculty of Life Sciences and Medicine, King's College London, UK
| | - Francesco Rubino
- 1 Division of Diabetes and Nutritional Sciences, King's College London, UK.,4 Department of Surgery, King's College Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
10
|
Seyfried F, Miras AD, Rotzinger L, Nordbeck A, Corteville C, Li JV, Schlegel N, Hankir M, Fenske W, Otto C, Jurowich C. Gastric Bypass-Related Effects on Glucose Control, β Cell Function and Morphology in the Obese Zucker Rat. Obes Surg 2018; 26:1228-36. [PMID: 26377340 DOI: 10.1007/s11695-015-1882-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Roux-en-Y gastric bypass (RYGB) may improve beta cell function by mechanisms other than caloric restriction and body weight loss. We aimed to assess the impact of anatomical and hormonal alterations specific to RYGB on glucose homeostasis, β cell function and morphology. METHODS Male Zucker(fa/fa) rats underwent either RYGB (n = 11) or sham surgeries (n = 10). Five of the shams were then food restricted and body weight matched (BWM) to the RYGB rats. Six male Zucker(fa/+) rats underwent sham surgery and served as additional lean controls. Twenty-seven days after surgery, an oral glucose tolerance test (OGTT) was performed and plasma levels of glucose, insulin and glucagon-like peptide-1 (GLP-1) were measured. Immunohistological analysis of pancreatic islets was performed, and GLP-1 receptor and PDX-1 mRNA content were quantified. RESULTS Shams consumed more food and gained more weight compared to both RYGB and BWM (p < 0.001). Hyperglycaemia was evident in ad libitum-fed shams, whilst postprandial glucose levels were lower in RYGB compared to the BWM sham group (p < 0.05). During the OGTT, RYGB rats responded with >2.5-fold increase of GLP-1. Histology revealed signs of islet degeneration in ad libitum-fed shams, but not in RYGB and sham BWM controls (p < 0.001). GLP-1 receptor and PDX-1 mRNA content was similar between the RYGB and BWM shams but higher compared to ad libitum shams (p < 0.05). CONCLUSIONS Combined molecular, cellular and histological analyses of pancreatic function suggest that weight loss alone, and not the enhancement of GLP-1 responses, is predominant for the short-term β cell protective effects of RYGB.
Collapse
Affiliation(s)
- Florian Seyfried
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany.
| | - Alexander D Miras
- Department of Investigative Medicine, Imperial College London, London, UK
| | - Laura Rotzinger
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany
| | - Arno Nordbeck
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany
| | - Caroline Corteville
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany
| | - Jia V Li
- Division of Computational and Systems Medicine, Imperial College London, London, UK
- Centre for Digestive and Gut Health, Department of Surgery and Cancer, Institute of Global Health Innovation, Imperial College London, London, UK
| | - Nicolas Schlegel
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany
| | - Mohammed Hankir
- Department of Medicine, Integrated Research and Treatment Centre for Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Wiebke Fenske
- Department of Medicine, Integrated Research and Treatment Centre for Adiposity Diseases, University of Leipzig, Leipzig, Germany
| | - Christoph Otto
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany
| | - Christian Jurowich
- Department of General, Visceral, Vascular and Pediatric Surgery, University Hospital of Wuerzburg, Oberduerrbacher Str. 6 97080, Wuerzburg, Germany
| |
Collapse
|
11
|
Stefanidis A, Oldfield BJ. Neuroendocrine mechanisms underlying bariatric surgery: Insights from human studies and animal models. J Neuroendocrinol 2017; 29. [PMID: 28887853 DOI: 10.1111/jne.12534] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/31/2017] [Accepted: 09/01/2017] [Indexed: 02/06/2023]
Abstract
Obesity has reached epidemic proportions and, to date, bariatric surgery remains the only effective treatment for morbid obesity in terms of its capacity to achieve durable weight loss. Bariatric surgery procedures, including Roux-en-Y gastric bypass (RYGB), adjustable gastric banding (AGB) and sleeve gastrectomy (SG), have been the primary procedures conducted over the past decade, with SG increasing in popularity over the past 5 years at the expense of both RYGB and AGB. Although these procedures were initially proposed to function via restrictive or malabsorptive mechanisms, it is now clear that profound physiological changes underlie the metabolic improvements in patients who undergo bariatric surgery. Data generated in human patients and animal models highlight the rapid and sustained changes in gut hormones that coincide with these procedures. Furthermore, recent studies highlight the involvement of the nervous system, specifically the vagus nerve, in mediating the reduction in appetite and food intake following bariatric surgery. What is unclear is where these pathways converge and interact within the gut-brain axis and whether vagally-mediated circuits are sufficient to drive the metabolic sequalae following bariatric surgery.
Collapse
Affiliation(s)
- A Stefanidis
- Department of Physiology, Monash University, Clayton, VIC, Australia
| | - B J Oldfield
- Metabolic Disease and Obesity Program, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| |
Collapse
|
12
|
Lutz TA, Bueter M. The Use of Rat and Mouse Models in Bariatric Surgery Experiments. Front Nutr 2016; 3:25. [PMID: 27547753 PMCID: PMC4974272 DOI: 10.3389/fnut.2016.00025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 07/26/2016] [Indexed: 12/11/2022] Open
Abstract
Animal models have been proven to be a crucial tool for investigating the physiological mechanisms underlying bariatric surgery in general and individual techniques in particular. By using a translational approach, most of these studies have been performed in rodents and have helped to understand how bariatric surgery may or may not work. However, data from studies using animal models should always be critically evaluated for their transferability to the human physiology. It is, therefore, the aim of this review to summarize both advantages and limitations of data generated by animal based experiments designed to investigate and understand the physiological mechanisms at the root of bariatric surgery.
Collapse
Affiliation(s)
- Thomas A Lutz
- Vetsuisse Faculty, Institute of Veterinary Physiology, University of Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Marco Bueter
- Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland; Department of Surgery, Division of Visceral and Transplant Surgery, University Hospital Zurich, Zurich, Switzerland
| |
Collapse
|
13
|
Mosinski JD, Pagadala MR, Mulya A, Huang H, Dan O, Shimizu H, Batayyah E, Pai RK, Schauer PR, Brethauer SA, Kirwan JP. Gastric bypass surgery is protective from high-fat diet-induced non-alcoholic fatty liver disease and hepatic endoplasmic reticulum stress. Acta Physiol (Oxf) 2016; 217:141-51. [PMID: 26663034 DOI: 10.1111/apha.12640] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 09/10/2015] [Accepted: 12/04/2015] [Indexed: 12/14/2022]
Abstract
AIM High-fat diets are known to contribute to the development of obesity and related co-morbidities including non-alcoholic fatty liver disease (NAFLD). The accumulation of hepatic lipid may increase endoplasmic reticulum (ER) stress and contribute to non-alcoholic steatohepatitis and metabolic disease. We hypothesized that bariatric surgery would counter the effects of a high-fat diet (HFD) on obesity-associated NAFLD. METHODS Sixteen of 24 male Sprague Dawley rats were randomized to Sham (N = 8) or Roux-en-Y gastric bypass (RYGB) surgery (N = 8) and compared to Lean controls (N = 8). Obese rats were maintained on a HFD throughout the study. Insulin resistance (HOMA-IR), and hepatic steatosis, triglyceride accumulation, ER stress and apoptosis were assessed at 90 days post-surgery. RESULTS Despite eating a HFD for 90 days post-surgery, the RYGB group lost weight (-20.7 ± 6%, P < 0.01) and improved insulin sensitivity (P < 0.05) compared to Sham. These results occurred with no change in food intake between groups. Hepatic steatosis and ER stress, specifically glucose-regulated protein-78 (Grp78, P < 0.001), X-box binding protein-1 (XBP-1) and spliced XBP-1 (P < 0.01), and fibroblast growth factor 21 (FGF21) gene expression, were normalized in the RYGB group compared to both Sham and Lean controls. Significant TUNEL staining in liver sections from the Obese Sham group, indicative of accelerated cell death, was absent in the RYGB and Lean control groups. Additionally, fasting plasma glucagon like peptide-1 was increased in RYGB compared to Sham (P < 0.02). CONCLUSION These data suggest that in obese rats, RYGB surgery protects the liver against HFD-induced fatty liver disease by attenuating ER stress and excess apoptosis.
Collapse
Affiliation(s)
- J. D. Mosinski
- Department of Pathobiology; Cleveland Clinic; Cleveland OH USA
| | - M. R. Pagadala
- Department of Gastroenterology & Hepatology; Cleveland Clinic; Cleveland OH USA
| | - A. Mulya
- Department of Pathobiology; Cleveland Clinic; Cleveland OH USA
| | - H. Huang
- Department of Pathobiology; Cleveland Clinic; Cleveland OH USA
| | - O. Dan
- Department of Bariatric Metabolic Institute; Cleveland Clinic; Cleveland OH USA
| | - H. Shimizu
- Department of Bariatric Metabolic Institute; Cleveland Clinic; Cleveland OH USA
| | - E. Batayyah
- Department of Bariatric Metabolic Institute; Cleveland Clinic; Cleveland OH USA
| | - R. K. Pai
- Department of Anatomic Pathology; Cleveland Clinic; Cleveland OH USA
| | - P. R. Schauer
- Department of Bariatric Metabolic Institute; Cleveland Clinic; Cleveland OH USA
- Metabolic Translational Research Center; Cleveland Clinic; Cleveland OH USA
| | - S. A. Brethauer
- Department of Bariatric Metabolic Institute; Cleveland Clinic; Cleveland OH USA
- Metabolic Translational Research Center; Cleveland Clinic; Cleveland OH USA
| | - J. P. Kirwan
- Department of Pathobiology; Cleveland Clinic; Cleveland OH USA
- Department of Gastroenterology & Hepatology; Cleveland Clinic; Cleveland OH USA
- Metabolic Translational Research Center; Cleveland Clinic; Cleveland OH USA
| |
Collapse
|
14
|
Spinelli V, Lalloyer F, Baud G, Osto E, Kouach M, Daoudi M, Vallez E, Raverdy V, Goossens JF, Descat A, Doytcheva P, Hubert T, Lutz TA, Lestavel S, Staels B, Pattou F, Tailleux A. Influence of Roux-en-Y gastric bypass on plasma bile acid profiles: a comparative study between rats, pigs and humans. Int J Obes (Lond) 2016; 40:1260-7. [PMID: 27089995 DOI: 10.1038/ijo.2016.46] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 02/03/2016] [Accepted: 02/21/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Roux-en-Y gastric bypass (RYGBP) is the most widely used bariatric surgery procedure, which induces profound metabolic and physiological effects, such as substantial improvements in obesity, type 2 diabetes and their comorbidities. Increasing evidence identifies bile acids (BAs) as signaling molecules that contribute to the metabolic improvement after RYGBP. However, how and to what extent BAs mediate the metabolic effects of RYGBP still remains unclear and requires mechanism of action studies using preclinical models. In this study, we compared plasma BA profiles before and after RYGBP in two animal models, rats and pigs, with humans to evaluate their translational potential. METHODS Plasma BAs were profiled in rats, pigs and humans by liquid chromatography coupled with tandem mass spectrometry before and after RYGBP. RESULTS RYGBP increased baseline plasma total BA concentrations in humans and in the two animal models to a similar extent (∼3-fold increase), despite differences in presurgery BA levels and profiles between the models. However, qualitatively, RYGBP differently affected individual plasma BA species, with similar increases in some free species (cholic acid (CA), chenodeoxycholic acid (CDCA) and deoxycholic acid (DCA)), different increases in glyco-conjugated species depending on the model and globally no increase in tauro-conjugated species whatever the model. CONCLUSIONS The tested animal models share similar quantitative RYGBP-induced increases in peripheral blood BAs as humans, which render them useful for mechanistic studies. However, they also present qualitative differences in BA profiles, which may result in different signaling responses. Such differences need to be taken into account when translating results to humans.
Collapse
Affiliation(s)
- V Spinelli
- Université Lille, U1011, EGID, Lille, France.,Inserm, U1011, Lille, France.,CHU Lille, Lille, France.,Institut Pasteur de Lille, U1011, Lille, France
| | - F Lalloyer
- Université Lille, U1011, EGID, Lille, France.,Inserm, U1011, Lille, France.,CHU Lille, Lille, France.,Institut Pasteur de Lille, U1011, Lille, France
| | - G Baud
- Université Lille, Inserm, UMR1190, EGID, Lille, France
| | - E Osto
- Swiss Federal Institute of Technology, ETH Zürich, Institute of Food Nutrition and Health, Zurich, Switzerland.,Department of Cardiology, Center for Molecular Cardiology, University of Zurich and University Heart Center, University Hospital Zurich, Zurich, Switzerland
| | - M Kouach
- Centre Universitaire de Mesures et d'Analyses, Université Lille, Lille, France
| | - M Daoudi
- Université Lille, Inserm, UMR1190, EGID, Lille, France
| | - E Vallez
- Université Lille, U1011, EGID, Lille, France.,Inserm, U1011, Lille, France.,CHU Lille, Lille, France.,Institut Pasteur de Lille, U1011, Lille, France
| | - V Raverdy
- CHU Lille, Lille, France.,Université Lille, Inserm, UMR1190, EGID, Lille, France
| | - J-F Goossens
- Centre Universitaire de Mesures et d'Analyses, Université Lille, Lille, France
| | - A Descat
- Centre Universitaire de Mesures et d'Analyses, Université Lille, Lille, France
| | - P Doytcheva
- Department of Cardiology, Center for Molecular Cardiology, University of Zurich and University Heart Center, University Hospital Zurich, Zurich, Switzerland.,Institute of Veterinary Physiology, Vetsuisse Faculty, Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - T Hubert
- Université Lille, Inserm, UMR1190, EGID, Lille, France
| | - T A Lutz
- Institute of Veterinary Physiology, Vetsuisse Faculty, Center of Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - S Lestavel
- Université Lille, U1011, EGID, Lille, France.,Inserm, U1011, Lille, France.,CHU Lille, Lille, France.,Institut Pasteur de Lille, U1011, Lille, France
| | - B Staels
- Université Lille, U1011, EGID, Lille, France.,Inserm, U1011, Lille, France.,CHU Lille, Lille, France.,Institut Pasteur de Lille, U1011, Lille, France
| | - F Pattou
- CHU Lille, Lille, France.,Université Lille, Inserm, UMR1190, EGID, Lille, France
| | - A Tailleux
- Université Lille, U1011, EGID, Lille, France.,Inserm, U1011, Lille, France.,CHU Lille, Lille, France.,Institut Pasteur de Lille, U1011, Lille, France
| |
Collapse
|
15
|
King A, Bowe J. Animal models for diabetes: Understanding the pathogenesis and finding new treatments. Biochem Pharmacol 2015; 99:1-10. [PMID: 26432954 DOI: 10.1016/j.bcp.2015.08.108] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 08/26/2015] [Indexed: 02/06/2023]
Abstract
Diabetes mellitus is a lifelong, metabolic disease that is characterised by an inability to maintain normal glucose homeostasis. There are several different forms of diabetes, however the two most common are Type 1 and Type 2 diabetes. Type 1 diabetes is caused by the autoimmune destruction of pancreatic beta cells and a subsequent lack of insulin production, whilst Type 2 diabetes is due to a combination of both insulin resistance and an inability of the beta cells to compensate adequately with increased insulin release. Animal models are increasingly being used to elucidate the mechanisms underlying both Type 1 and Type 2 diabetes as well as to identify and refine novel treatments. However, a wide range of different animal models are currently in use. The majority of these models are suited to addressing certain specific aspects of diabetes research, but may be of little use in other studies. All have pros and cons, and selecting an appropriate model for addressing a specific question is not always a trivial task and will influence the study results and their interpretation. Thus, as the number of available animal models increases it is important to consider the potential roles of these models in the many different aspects of diabetes research. This review gathers information on the currently used experimental animal models of both Type 1 and Type 2 diabetes and evaluates their advantages and disadvantages for research purposes and details the factors that should be taken into account in their use.
Collapse
Affiliation(s)
- Aileen King
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Hodgkin Building 2nd Floor, Guy's Campus, King's College London, London SE1 1UL, United Kingdom.
| | - James Bowe
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Hodgkin Building 2nd Floor, Guy's Campus, King's College London, London SE1 1UL, United Kingdom
| |
Collapse
|
16
|
Manning S, Pucci A, Batterham RL. GLP-1: a mediator of the beneficial metabolic effects of bariatric surgery? Physiology (Bethesda) 2015; 30:50-62. [PMID: 25559155 DOI: 10.1152/physiol.00027.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There has been increasing interest in the role that gut hormones may play in contributing to the physiological changes produced by certain bariatric procedures, such as Roux-en-Y gastric bypass and sleeve gastrectomy. Here, we review the evidence implicating one such gut hormone, glucagon-like peptide-1, as a mediator of the metabolic benefits of these two procedures.
Collapse
Affiliation(s)
- Sean Manning
- Department of Medicine, Centre for Obesity Research, Rayne Institute, University College London, London, United Kingdom; UCLH Centre for Weight Loss, Metabolic and Endocrine Surgery, University College London Hospitals, London, United Kingdom; National Institute of Health Research University College London Hospitals Biomedical Research Centre, London, United Kingdom
| | - Andrea Pucci
- Department of Medicine, Centre for Obesity Research, Rayne Institute, University College London, London, United Kingdom; UCLH Centre for Weight Loss, Metabolic and Endocrine Surgery, University College London Hospitals, London, United Kingdom
| | - Rachel L Batterham
- Department of Medicine, Centre for Obesity Research, Rayne Institute, University College London, London, United Kingdom; UCLH Centre for Weight Loss, Metabolic and Endocrine Surgery, University College London Hospitals, London, United Kingdom; National Institute of Health Research University College London Hospitals Biomedical Research Centre, London, United Kingdom
| |
Collapse
|
17
|
Lau RG, Kumar S, Hall CE, Palaia T, Rideout DA, Hall K, Brathwaite CE, Ragolia L. Roux-en-Y gastric bypass attenuates the progression of cardiometabolic complications in obese diabetic rats via alteration in gastrointestinal hormones. Surg Obes Relat Dis 2015; 11:1044-53. [PMID: 25980330 DOI: 10.1016/j.soard.2014.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/10/2014] [Accepted: 12/05/2014] [Indexed: 01/20/2023]
|
18
|
Corteville C, Fassnacht M, Bueter M. [Surgery as pluripotent instrument for metabolic disease. What are the mechanisms?]. Chirurg 2015; 85:963-8. [PMID: 25312490 DOI: 10.1007/s00104-014-2796-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Bariatric metabolic surgery currently offers the most effective treatment to achieve sustained weight loss and improvement in metabolic comorbidities, such as type 2 diabetes, hypertension, dyslipidemia and cardiovascular diseases. The number of cases performed in Germany and also worldwide is continuously increasing but the underlying mechanisms of bariatric metabolic surgery are still not completely elucidated. Roux-en-Y gastric bypass (RYGB) surgery represents one of the most commonly used and therefore most frequently investigated bariatric metabolic procedures. Traditionally, its effectiveness was attributed to food restriction and malabsorption but in the meantime it has become evident that the underlying postoperative mechanisms of RYGB seem to be much more complex. Potential mechanisms include multiple physiological changes, such as altered levels of gastrointestinal hormones, increased energy expenditure and modified gut microbiota as well as many other factors. This review article therefore aims to offer an up to date overview of relevant mechanisms that improve obesity and its associated comorbidities after RYGB surgery.
Collapse
Affiliation(s)
- C Corteville
- Klinik und Poliklinik für Allgemein-, Viszeral-, Gefäß- und Kinderchirurgie, Universitätsklinikum Würzburg, Würzburg, Deutschland
| | | | | |
Collapse
|
19
|
Arapis K, Cavin JB, Gillard L, Cluzeaud F, Lettéron P, Ducroc R, Le Beyec J, Hourseau M, Couvelard A, Marmuse JP, Le Gall M, Bado A. Remodeling of the residual gastric mucosa after roux-en-y gastric bypass or vertical sleeve gastrectomy in diet-induced obese rats. PLoS One 2015; 10:e0121414. [PMID: 25822172 PMCID: PMC4379088 DOI: 10.1371/journal.pone.0121414] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 01/31/2015] [Indexed: 01/06/2023] Open
Abstract
Whereas the remodeling of intestinal mucosa after bariatric surgeries has been the matter of numerous studies to our knowledge, very few reported on the remodeling of the residual gastric mucosa. In this study, we analyzed remodeling of gastric mucosa after Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) in rats. Diet-induced obese rats were subjected to RYGB, VSG or sham surgical procedures. All animals were assessed for food intake, body-weight, fasting blood, metabolites and hormones profiling, as well as insulin and glucose tolerance tests before and up to 5 weeks post-surgery. Remodeling of gastric tissues was analyzed by routine histology and immunohistochemistry studies, and qRT-PCR analyses of ghrelin and gastrin mRNA levels. In obese rats with impaired glucose tolerance, VSG and RYGB caused substantial weight loss and rats greatly improved their oral glucose tolerance. The remaining gastric mucosa after VSG and gastric pouch (GP) after RYGB revealed a hyperplasia of the mucous neck cells that displayed a strong immunoreactivity for parietal cell H+/K+-ATPase. Ghrelin mRNA levels were reduced by 2-fold in remaining fundic mucosa after VSG and 10-fold in GP after RYGB. In the antrum, gastrin mRNA levels were reduced after VSG in line with the reduced number of gastrin positive cells. This study reports novel and important observations dealing with the remaining gastric mucosa after RYGB and VSG. The data demonstrate, for the first time, a hyperplasia of the mucous neck cells, a transit cell population of the stomach bearing differentiating capacities into zymogenic and peptic cells.
Collapse
Affiliation(s)
- Konstantinos Arapis
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
- Service de Chirurgie Générale et Digestive; Hôpital Bichat—Claude Bernard. Paris, France
| | - Jean Baptiste Cavin
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - Laura Gillard
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - Françoise Cluzeaud
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - Philippe Lettéron
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - Robert Ducroc
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - Johanne Le Beyec
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - Muriel Hourseau
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
- Département de Pathologie; Hôpital Bichat—Claude Bernard, Paris, France
| | - Anne Couvelard
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
- Département de Pathologie; Hôpital Bichat—Claude Bernard, Paris, France
| | - Jean-Pierre Marmuse
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
- Service de Chirurgie Générale et Digestive; Hôpital Bichat—Claude Bernard. Paris, France
| | - Maude Le Gall
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
| | - André Bado
- Inserm UMR 1149, UFR de Médecine Paris Diderot, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- DHU Unity, Bichat-Beaujon AP-HP, Paris, France
- * E-mail:
| |
Collapse
|
20
|
Manning S, Pucci A, Batterham RL. Roux-en-Y gastric bypass: effects on feeding behavior and underlying mechanisms. J Clin Invest 2015; 125:939-48. [PMID: 25729850 DOI: 10.1172/jci76305] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Bariatric surgery is the most effective treatment for severe obesity, producing marked sustained weight loss with associated reduced morbidity and mortality. Roux-en-Y gastric bypass surgery (RYGBP), the most commonly performed procedure, was initially viewed as a hybrid restrictive-malabsorptive procedure. However, over the last decade, it has become apparent that alternative physiologic mechanisms underlie its beneficial effects. RYGBP-induced altered feeding behavior, including reduced appetite and changes in taste/food preferences, is now recognized as a key driver of the sustained postoperative weight loss. The brain ultimately determines feeding behavior, and here we review the mechanisms by which RYGBP may affect central appetite-regulating pathways.
Collapse
|
21
|
Ingram DK, Roth GS. Calorie restriction mimetics: can you have your cake and eat it, too? Ageing Res Rev 2015; 20:46-62. [PMID: 25530568 DOI: 10.1016/j.arr.2014.11.005] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 11/25/2014] [Accepted: 11/25/2014] [Indexed: 12/31/2022]
Abstract
Strong consensus exists regarding the most robust environmental intervention for attenuating aging processes and increasing healthspan and lifespan: calorie restriction (CR). Over several decades, this paradigm has been replicated in numerous nonhuman models, and has been expanded over the last decade to formal, controlled human studies of CR. Given that long-term CR can create heavy challenges to compliance in human diets, the concept of a calorie restriction mimetic (CRM) has emerged as an active research area within gerontology. In past presentations on this subject, we have proposed that a CRM is a compound that mimics metabolic, hormonal, and physiological effects of CR, activates stress response pathways observed in CR and enhances stress protection, produces CR-like effects on longevity, reduces age-related disease, and maintains more youthful function, all without significantly reducing food intake, at least initially. Over 16 years ago, we proposed that glycolytic inhibition could be an effective strategy for developing CRM. The main argument here is that inhibiting energy utilization as far upstream as possible provides the highest chance of generating a broad spectrum of CR-like effects when compared to targeting a singular molecular target downstream. As an initial candidate CRM, 2-deoxyglucose, a known anti-glycolytic, was shown to produce a remarkable phenotype of CR, but further investigation found that this compound produced cardiotoxicity in rats at the doses we had been using. There remains interest in 2DG as a CRM but at lower doses. Beyond the proposal of 2DG as a candidate CRM, the field has grown steadily with many investigators proposing other strategies, including novel anti-glycolytics. Within the realm of upstream targeting at the level of the digestive system, research has included bariatric surgery, inhibitors of fat digestion/absorption, and inhibitors of carbohydrate digestion. Research focused on downstream sites has included insulin receptors, IGF-1 receptors, sirtuin activators, inhibitors of mTOR, and polyamines. In the current review we discuss progress made involving these various strategies and comment on the status and future for each within this exciting research field.
Collapse
Affiliation(s)
- Donald K Ingram
- Nutritional Neuroscience and Aging Laboratory, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Road, Baton Rouge, LA 70809, United States.
| | - George S Roth
- GeroScience, Inc., Pylesville, MD 21132, United States.
| |
Collapse
|
22
|
Lindqvist A, Spégel P, Ekelund M, Garcia Vaz E, Pierzynowski S, Gomez MF, Mulder H, Hedenbro J, Groop L, Wierup N. Gastric bypass improves β-cell function and increases β-cell mass in a porcine model. Diabetes 2014; 63:1665-71. [PMID: 24487021 DOI: 10.2337/db13-0969] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The most frequently used and effective treatment for morbid obesity is Roux-en-Y gastric bypass surgery (RYGB), which results in rapid remission of type 2 diabetes in most cases. To what extent this is accounted for by weight loss or other factors remains elusive. To gain insight into these mechanisms, we investigated the effects of RYGB on β-cell function and β-cell mass in the pig, a species highly reminiscent of the human. RYGB was performed using linear staplers during open surgery. Sham-operated pigs were used as controls. Both groups were fed a low-calorie diet for 3 weeks after surgery. Intravenous glucose tolerance tests were performed 2 weeks after surgery. Body weight in RYGB pigs and sham-operated, pair-fed control pigs developed similarly. RYGB pigs displayed improved glycemic control, which was attributed to increases in β-cell mass, islet number, and number of extraislet β-cells. Pancreatic expression of insulin and glucagon was elevated, and cells expressing the glucagon-like peptide 1 receptor were more abundant in RYGB pigs. Our data from a pig model of RYGB emphasize the key role of improved β-cell function and β-cell mass to explain the improved glucose tolerance after RYGB as food intake and body weight remained identical.
Collapse
Affiliation(s)
- Andreas Lindqvist
- Department of Clinical Sciences, Lund University Diabetes Centre, Malmö, Sweden
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Manning S, Batterham RL. The Role of Gut Hormone Peptide YY in Energy and Glucose Homeostasis: Twelve Years On. Annu Rev Physiol 2014; 76:585-608. [DOI: 10.1146/annurev-physiol-021113-170404] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sean Manning
- Centre for Obesity Research, Rayne Institute, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom; ,
| | - Rachel L. Batterham
- Centre for Obesity Research, Rayne Institute, Department of Medicine, University College London, London WC1E 6JJ, United Kingdom; ,
| |
Collapse
|
24
|
Abstract
The clinical efficacy of bariatric surgery has encouraged the scientific investigation of the gut as a major endocrine organ. Manipulation of gastrointestinal anatomy through surgery has been shown to profoundly affect the physiological and metabolic processes that control body weight and glycaemia. The most popular bariatric surgical procedures are gastric bypass, adjustable gastric banding and vertical sleeve gastrectomy. Even though these procedures were designed with the aim of causing restriction of food intake and nutrient malabsorption, evidence suggests that their contributions to weight loss are minimal. Instead, these interventions reduce body weight by decreasing hunger, increasing satiation during a meal, changing food preferences and energy expenditure. In this Review, we have explored these mechanisms as well as their mediators. The hope is that that their in-depth investigation will enable the optimization and individualization of surgical techniques, the development of equally effective but safer nonsurgical weight-loss interventions, and even the understanding of the pathophysiology of obesity itself.
Collapse
Affiliation(s)
- Alexander D Miras
- Molecular and Metabolic Imaging Group, Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital, London W12 0NN, UK
| | | |
Collapse
|
25
|
Birck MM, Vegge A, Støckel M, Gögenur I, Thymann T, Hammelev KP, Sangild PT, Hansen AK, Raun K, von Voss P, Eriksen T. Laparoscopic Roux-en-Y gastric bypass in super obese Göttingen minipigs. Am J Transl Res 2013; 5:643-653. [PMID: 24093061 PMCID: PMC3786271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 09/15/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND The specific mechanisms behind weight loss and comorbidity improvements in obese patients after Roux-en-Y gastric bypass (RYGBP) are still poorly understood. The aim of this study was to establish and evaluate the feasibility of a long-term survival RYGBP model in super obese Göttingen minipigs in order to improve the translational potential relative to current animal models. METHODS Eleven Göttingen minipigs with diet-induced obesity underwent laparoscopic RYGBP and were followed up to 9 months after surgery. Intra- and post-operative complications, body weight (BW), food intake and necropsy data were recorded. RESULTS Five minipigs survived without complications to the end of the study. Four minipigs developed surgical related complications and were euthanized while two minipigs died due to central venous catheter related complications. BW and food intake is reported for the six minipigs surviving longer than 4.5 months post-surgery. Weight loss and reduced food intake was seen in all minipigs. After 2-3 months of weight loss, weight regain was evident in all but two minipigs which seemed to continue losing weight. Necropsy revealed some variation in the length of the alimentary, biliary and common limb between minipigs. CONCLUSION The use of obese Göttingen minipigs as a translational RYGBP model is feasible and has potential for the study of RYGBP-related changes in gut function, type-2 diabetes and appetite regulation. Still, the surgical procedure is technically highly demanding in obese Göttingen minipigs and the peri-operative animal care and follow up requires close monitoring.
Collapse
Affiliation(s)
- Malene M Birck
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of CopenhagenDenmark
| | - Andreas Vegge
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of CopenhagenDenmark
- Diabetes Pharmacology, Novo Nordisk A/SDenmark
| | - Mikael Støckel
- Department of Surgery, Copenhagen University HospitalHerlev, Denmark
| | - Ismail Gögenur
- Department of Surgery, Copenhagen University HospitalHerlev, Denmark
| | - Thomas Thymann
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of CopenhagenDenmark
| | - Karsten P Hammelev
- Department of Experimental Medicine, Faculty of Health and Medical Sciences, University of CopenhagenDenmark
| | - Per T Sangild
- Department of Nutrition, Exercise and Sports, Faculty of Science, University of CopenhagenDenmark
| | - Axel K Hansen
- Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of CopenhagenDenmark
| | | | | | - Thomas Eriksen
- Department of Veterinary Clinical and Animal Science, Faculty of Health and Medical Sciences, University of CopenhagenDenmark
| |
Collapse
|
26
|
Papamargaritis D, Panteliou E, Miras AD, le Roux CW. Mechanisms of weight loss, diabetes control and changes in food choices after gastrointestinal surgery. Curr Atheroscler Rep 2013; 14:616-23. [PMID: 23001746 DOI: 10.1007/s11883-012-0283-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The long-term effects of lifestyle changes, diet and medical therapy on obesity are limited. Bariatric surgery is the most effective long-term treatment with the greatest chances for amelioration of obesity-associated complications, including type 2 diabetes mellitus (T2DM). There is increasing evidence in the literature that bariatric operations have a profound effect on human physiology, by reducing hunger, increasing satiety, paradoxically increasing energy expenditure, and even promoting healthy food preferences. Some of these operations improve glucose homeostasis in patients with T2DM independently of weight loss. Changes in the gut hormone levels of glucagon-like peptide 1, peptide YY and ghrelin have been proposed as some of the mediators implicated in changing physiology. The aim of this review is to critically explore the current knowledge on the putative mechanisms of the change in weight and improvement in T2DM glycaemic control after the most commonly performed bariatric operations.
Collapse
|
27
|
Seyfried F, Li JV, Miras AD, Cluny NL, Lannoo M, Fenske WK, Sharkey KA, Nicholson JK, le Roux CW, Holmes E. Urinary Phenotyping Indicates Weight Loss-Independent Metabolic Effects of Roux-en-Y Gastric Bypass in Mice. J Proteome Res 2013; 12:1245-53. [DOI: 10.1021/pr300909v] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Florian Seyfried
- Department of General- and Visceral,
Vascular- and Pediatric Surgery, University Hospital of Wuerzburg, Germany
- Department of Investigative Medicine, Imperial College London, London, United Kingdom
| | - Jia V. Li
- Department of Surgery and Cancer,
Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Alexander D. Miras
- Department of Investigative Medicine, Imperial College London, London, United Kingdom
- Molecular
and Metabolic Imaging Group,
Clinical Sciences Centre, Imperial College London, Hammersmith Hospital, London, United Kingdom
| | - Nina L. Cluny
- Hotchkiss Brain Institute and
Snyder Institute for Chronic Diseases, Department of Physiology and
Pharmacology, University of Calgary, Calgary,
Alberta, Canada
| | - Matthias Lannoo
- Department of
Abdominal Surgery, University of Leuven, Belgium
| | - Wiebke K. Fenske
- Department of
Internal Medicine, University Hospital of Wuerzburg, Germany
| | - Keith A Sharkey
- Hotchkiss Brain Institute and
Snyder Institute for Chronic Diseases, Department of Physiology and
Pharmacology, University of Calgary, Calgary,
Alberta, Canada
| | - Jeremy K. Nicholson
- Department of Surgery and Cancer,
Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Carel W. le Roux
- Department of Investigative Medicine, Imperial College London, London, United Kingdom
- Experimental
Pathology, Conway
Institute, School of Medicine and Medical Sciences, University College Dublin, Ireland
| | - Elaine Holmes
- Department of Surgery and Cancer,
Faculty of Medicine, Imperial College London, London, United Kingdom
| |
Collapse
|
28
|
Thanos PK, Subrize M, Delis F, Cooney RN, Culnan D, Sun M, Wang GJ, Volkow ND, Hajnal A. Gastric bypass increases ethanol and water consumption in diet-induced obese rats. Obes Surg 2012; 22:1884-92. [PMID: 22976430 PMCID: PMC3615544 DOI: 10.1007/s11695-012-0749-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Roux-en-Y gastric bypass surgery (RYGB) is an effective treatment for morbid obesity. Increased alcohol abuse after RYGB resulted in recommendations to exclude patients with alcohol abuse histories from RYGB. The purpose of our study was to examine the effects of a RYGB on ethanol intake in diet-induced obese rats (high-fat diet). METHODS The animals underwent RYGB and were habituated along with their sham-operated obese controls and with lean rats to increasing concentrations of ethanol in a two-bottle choice paradigm. RESULTS RYGB rats' daily consumption of ethanol averaged 2 g/kg at 2% habituation and 3.8 g/kg at 4% habituation, twice as much as sham-operated obese controls and 50% more than normal-diet lean controls. Obese controls drank on average 1 g/kg of ethanol (2 and 4%), significantly less (50%) than lean controls did. RYGB rats when given higher ethanol concentrations (6 and 8%) or no ethanol drank significantly more water than lean and obese controls did (66 and 100%, respectively), and their enhanced total fluid intake was associated with increased food intake, which was significantly higher than in lean (66% more calories; food + alcohol) and obese controls (44% more calories). The lower alcohol intake in the obese controls than in the lean rats suggests that obesity may interfere with alcohol's rewarding effects and RYGB may remove this protective effect. CONCLUSIONS The overall enhancement of consummatory behaviors (both ethanol and water) suggests that RYGB may facilitate alcohol consumption, which in vulnerable individuals could lead to abuse and addiction.
Collapse
Affiliation(s)
- Panayotis K. Thanos
- Laboratory of Neuroimaging, NIAAA Intramural Program, NIH
- Behavioral Neuropharmacology and Neuroimaging Lab, Brookhaven National Laboratory, Upton, NY
| | - Mike Subrize
- Behavioral Neuropharmacology and Neuroimaging Lab, Brookhaven National Laboratory, Upton, NY
| | - Foteini Delis
- Behavioral Neuropharmacology and Neuroimaging Lab, Brookhaven National Laboratory, Upton, NY
| | | | | | - Mingjie Sun
- Dept. of Neural and Behavioral Sciences, Penn State University
- Dept. of Surgery, Penn State University
| | - Gene-Jack Wang
- Behavioral Neuropharmacology and Neuroimaging Lab, Brookhaven National Laboratory, Upton, NY
| | - Nora D. Volkow
- Laboratory of Neuroimaging, NIAAA Intramural Program, NIH
| | - Andras Hajnal
- Dept. of Neural and Behavioral Sciences, Penn State University
- Dept. of Surgery, Penn State University
| |
Collapse
|
29
|
Bueter M, Abegg K, Seyfried F, Lutz TA, le Roux CW. Roux-en-Y gastric bypass operation in rats. J Vis Exp 2012:e3940. [PMID: 22710348 DOI: 10.3791/3940] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Currently, the most effective therapy for the treatment of morbid obesity to induce significant and maintained body weight loss with a proven mortality benefit is bariatric surgery. Consequently, there has been a steady rise in the number of bariatric operations done worldwide in recent years with the Roux-en-Y gastric bypass (gastric bypass) being the most commonly performed operation. Against this background, it is important to understand the physiological mechanisms by which gastric bypass induces and maintains body weight loss. These mechanisms are yet not fully understood, but may include reduced hunger and increased satiation, increased energy expenditure, altered preference for food high in fat and sugar, altered salt and water handling of the kidney as well as alterations in gut microbiota. Such changes seen after gastric bypass may at least partly stem from how the surgery alters the hormonal milieu because gastric bypass increases the postprandial release of peptide-YY (PYY) and glucagon-like-peptide-1 (GLP-1), hormones that are released by the gut in the presence of nutrients and that reduce eating. During the last two decades numerous studies using rats have been carried out to further investigate physiological changes after gastric bypass. The gastric bypass rat model has proven to be a valuable experimental tool not least as it closely mimics the time profile and magnitude of human weight loss, but also allows researchers to control and manipulate critical anatomic and physiologic factors including the use of appropriate controls. Consequently, there is a wide array of rat gastric bypass models available in the literature reviewed elsewhere in more detail. The description of the exact surgical technique of these models varies widely and differs e.g. in terms of pouch size, limb lengths, and the preservation of the vagal nerve. If reported, mortality rates seem to range from 0 to 35%. Furthermore, surgery has been carried out almost exclusively in male rats of different strains and ages. Pre- and postoperative diets also varied significantly. Technical and experimental variations in published gastric bypass rat models complicate the comparison and identification of potential physiological mechanisms involved in gastric bypass. There is no clear evidence that any of these models is superior, but there is an emerging need for standardization of the procedure to achieve consistent and comparable data. This article therefore aims to summarize and discuss technical and experimental details of our previously validated and published gastric bypass rat model.
Collapse
Affiliation(s)
- Marco Bueter
- Department of Surgery, University Hospital Zürich.
| | | | | | | | | |
Collapse
|
30
|
Seyfried F, Lannoo M, Gsell W, Tremoleda JL, Bueter M, Olbers T, Jurowich C, Germer CT, le Roux CW. Roux-en-Y Gastric Bypass in Mice—Surgical Technique and Characterisation. Obes Surg 2012; 22:1117-25. [DOI: 10.1007/s11695-012-0661-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|