1
|
Pereira RO, Correia LA, Farah D, Komoni G, Farah V, Fiorino P. Wistar rat as an animal model to study high-fat induced kidney damage: a systematic review. Arch Physiol Biochem 2024; 130:205-214. [PMID: 34915796 DOI: 10.1080/13813455.2021.2017462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 11/08/2021] [Accepted: 12/07/2021] [Indexed: 12/09/2022]
Abstract
The effects of high-fat-associated kidney damage in humans are not completely elucidated. Animal experiments are essential to understanding the mechanisms underlying human diseases. This systematic review aimed to compile evidence of the role of a high-fat diet during the development of renal lipotoxicity and fibrosis of Wistar rats to understand whether this is a satisfactory model for the study of high fat-induced kidney damage. We conducted systematic searches in PUBMED, EMBASE, Lilacs, and Web of Science databases from inception until May 2021. The risk of bias was assessed using SYRCLE toll. Two reviewers independently screened abstracts and reviewed full-text articles. A total of 11 studies were included. The damage varied depending on the age and sex of the animals, time of protocol, and amount of fat in the diet. In conclusion, the Wistar rat is an adequate animal model to assess the effects of a high-fat diet on the kidneys.HighlightsA high-fat diet may promote kidney damage in Wistar rats.Wistar rat is efficient as an animal model to study high-fat-induced kidney damage.The effect of the diet depends on the fat amount, consumption time, and animal age.
Collapse
Affiliation(s)
- Renata O Pereira
- Translational Medicine Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
- Renal, Cardiovascular and Metabolic Physiopharmacology Laboratory, Health and Biological Science Center, Mackenzie University, São Paulo, Brazil
| | - Luana A Correia
- Renal, Cardiovascular and Metabolic Physiopharmacology Laboratory, Health and Biological Science Center, Mackenzie University, São Paulo, Brazil
| | - Daniela Farah
- Women's Health Technology Assessment Center, Department of Gynecology, Federal University of São Paulo, São Paulo, Brazil
| | - Geovana Komoni
- Translational Medicine Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
- Renal, Cardiovascular and Metabolic Physiopharmacology Laboratory, Health and Biological Science Center, Mackenzie University, São Paulo, Brazil
| | - Vera Farah
- Translational Medicine Division, Department of Medicine, Federal University of São Paulo, São Paulo, Brazil
- Renal, Cardiovascular and Metabolic Physiopharmacology Laboratory, Health and Biological Science Center, Mackenzie University, São Paulo, Brazil
| | - Patricia Fiorino
- Renal, Cardiovascular and Metabolic Physiopharmacology Laboratory, Health and Biological Science Center, Mackenzie University, São Paulo, Brazil
| |
Collapse
|
2
|
Guo Y, Zhao H, Wang F, Xu H, Liu X, Hu T, Wu D. Telomere length as a marker of changes in body composition and fractures-an analysis of data from the NHANES 2001-2002. Front Immunol 2023; 14:1181544. [PMID: 37744360 PMCID: PMC10514483 DOI: 10.3389/fimmu.2023.1181544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 08/23/2023] [Indexed: 09/26/2023] Open
Abstract
Purpose There has been an association between changes in body composition, fracture incidence, and age in previous studies. Telomere length (TL) has been proposed as a biomarker of aging. However, the relationship between body composition, fractures, and TL has rarely been studied. Therefore, this study aimed to investigate the correlation between TL and body composition and fractures.Patients and methods: 20950 participants from the 2001-2002 National Health and Nutrition Examination Survey (NHANES) were included in the final analysis. In NHANES, body compositions were measured with DXA, and TL was determined with quantitative PCR. Correlation analysis of TL and body composition was conducted using multivariate weighted linear regression and logistic regression models. Results The results showed that TL positively correlated with bone mineral density (BMD) and bone mineral content (BMC) in most body parts. However, BMD and BMC were negatively connected with TL in the upper limbs and skull. Fat content was negatively associated with TL, while muscle content was positively linked to TL. In addition, TL's trend analysis results were consistent with the regression model when transformed from a continuous to a classified variable. An increase in TL was associated with a higher incidence of wrist fractures, while a decrease in spine fractures. The above correlation also has a certain degree of sex specificity. Conclusion Our study indicate that TL is associated with body composition as well as fractures, but further research is needed to confirm these contrasting associations in the skull, upper limbs, and wrists.
Collapse
Affiliation(s)
| | | | | | | | | | - Tao Hu
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Desheng Wu
- Department of Spine Surgery, Shanghai East Hospital, School of Medicine, Tongji University, Shanghai, China
| |
Collapse
|
3
|
Yang Y, Zhang Q, Ren J, Zhu Q, Wang L, Zhang Y, Geng Z. Evolution of Brain Morphology in Spontaneously Hypertensive and Wistar-Kyoto Rats From Early Adulthood to Aging: A Longitudinal Magnetic Resonance Imaging Study. Front Aging Neurosci 2021; 13:757808. [PMID: 34916922 PMCID: PMC8670306 DOI: 10.3389/fnagi.2021.757808] [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: 08/12/2021] [Accepted: 11/08/2021] [Indexed: 11/21/2022] Open
Abstract
The influence of hypertension and aging alone on brain structure has been described extensively. Our understanding of the interaction of hypertension with aging to brain morphology is still limited. We aimed to detect the synergistic effects of hypertension and aging on brain morphology and to describe the evolution patterns of cerebral atrophy from spatial and temporal perspectives. In 8 spontaneously hypertensive rats (SHRs) and 5 Wistar-Kyoto rats, high-resolution magnetic resonance imaging scans were longitudinally acquired at 10, 24, 52, and 80 weeks. We analyzed the tissue volumes of gray matter, white matter, cerebral spinal fluid, and total intracranial volume (TIV), and then evaluated gray matter volume in detail using voxel-based morphometry (VBM) and region of interest-based methods. There were interactive effects on hypertension and aging in tissue volumes of gray matter, white matter, and TIV, of which gray matter atrophy was most pronounced, especially in elderly SHRs. We identified the vulnerable gray matter volume with combined effects of hypertension and aging in the septal region, bilateral caudate putamen, hippocampus, primary somatosensory cortex, cerebellum, periaqueductal gray, right accumbens nucleus, and thalamus. We automatically extracted the septal region, anterior cingulate cortex, primary somatosensory cortex, caudate putamen, hippocampus, and accumbens nucleus and revealed an inverted-U trajectory of volume change in SHRs, with volume increase at the early phase and decline at the late phase. Hypertension interacts with aging to affect brain volume changes such as severe atrophy in elderly SHRs.
Collapse
Affiliation(s)
- Yingying Yang
- Graduate School, Hebei Medical University, Shijiazhuang, China.,Department of Imaging, The First Hospital of Qinhuangdao, Qinhuangdao, China
| | - Quan Zhang
- Tianjin Key Laboratory of Functional Imaging, Department of Radiology, Tianjin Medical University General Hospital, Tianjin, China
| | | | - Qingfeng Zhu
- Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Lixin Wang
- Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Yongzhi Zhang
- Graduate School, Hebei Medical University, Shijiazhuang, China
| | - Zuojun Geng
- Department of Medical Imaging, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| |
Collapse
|
4
|
Moser VA, Christensen A, Liu J, Zhou A, Yagi S, Beam CR, Galea L, Pike CJ. Effects of aging, high-fat diet, and testosterone treatment on neural and metabolic outcomes in male brown Norway rats. Neurobiol Aging 2019; 73:145-160. [PMID: 30359877 PMCID: PMC6252085 DOI: 10.1016/j.neurobiolaging.2018.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 07/01/2018] [Accepted: 09/13/2018] [Indexed: 12/23/2022]
Abstract
Risk for Alzheimer's disease (AD) is affected by multiple factors, including aging, obesity, and low testosterone. We previously showed that obesity and low testosterone independently and interactively exacerbate AD-related outcomes in young adult rodents. The goals of the present study are two-fold: to examine whether the effects of an obesogenic diet differ with increasing age and to determine if testosterone treatment in middle-aged and aged animals mitigates negative effects of the diet. Male brown Norway rats were maintained on control or high-fat diets for 12 weeks beginning in young adulthood, middle age, or advanced age. Separate cohorts of middle-aged and aged animals were treated with testosterone during dietary manipulations. Endpoints included metabolic indices, inflammation, cognitive performance, and neural health outcomes. Aging was associated with poorer outcomes that were generally exacerbated by high-fat diet, especially at middle age. Testosterone treatment was largely without benefit, exerting only subtle effects on a select number of measures. Understanding how the deleterious effects of obesity are affected by advancing age and the ability of protective strategies such as testosterone to reduce these effects may provide significant insight into both the development and prevention of age-related cognitive decline and AD.
Collapse
Affiliation(s)
- V Alexandra Moser
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Amy Christensen
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Jiahui Liu
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Amanda Zhou
- Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA
| | - Shunya Yagi
- Djavad Mowafaghian Centre for Brain Health, Department of Psychology, University of British Columbia, Vancouver BC, Canada
| | - Christopher R Beam
- Department of Psychology, University of Southern California, Los Angeles, CA, USA
| | - Liisa Galea
- Djavad Mowafaghian Centre for Brain Health, Department of Psychology, University of British Columbia, Vancouver BC, Canada
| | - Christian J Pike
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA; Leonard Davis School of Gerontology, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
5
|
Moreno JM, Tapia A, Martinez CM, Reverte V, Oltra L, Llinas MT, Salazar FJ. Sex-dependent differences in the adverse renal changes induced by an early in life exposure to a high-fat diet. Am J Physiol Renal Physiol 2018; 316:F332-F340. [PMID: 30516421 DOI: 10.1152/ajprenal.00394.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examines whether the intake of a high-fat diet very early in life leads to changes in arterial pressure and renal function and evaluates whether the mechanisms involved in these changes are sex-dependent. Experiments were performed in male and female Sprague-Dawley rats fed a normal or high-fat diet from weaning to 4 mo of age. This exposure to a high-fat diet lead to an angiotensin II-dependent elevation in arterial pressure and to significant increments in fat abdominal volume and plasma leptin that were similar in both sexes. In addition, the angiotensin II-induced increment in renal vascular resistance was greater ( P < 0.05) in male (106 ± 14%) and female (97 ± 15%) rats fed a high-fat diet than in rats fed a normal-fat diet (51 ± 8%). However, the high-fat intake during early life induced increments in albuminuria, interleukin-6, and infiltration of CD3 lymphocytes in the renal parenchyma that were greater ( P < 0.05) in male than in female rats. Other sex-dependent differences in response to high-fat intake were that adiponectin levels only decreased in females (21%, P < 0.05), and renal NF-κB expression only increased in males (31%, P < 0.05). In summary, the early exposure to a high-fat diet leads to angiotensin II-dependent arterial pressure elevations and to increments in abdominal fat and in the renal sensitivity to angiotensin II that are similar in both sexes. However, the mechanisms involved in the renal changes associated with early exposure to a high-fat diet are different in males and females.
Collapse
Affiliation(s)
- Juan M Moreno
- Department of Physiology, School of Medicine, University of Murcia and Biomedical Research Institute of Murcia , Murcia , Spain
| | - Antonio Tapia
- Department of Physiology, School of Medicine, University of Murcia and Biomedical Research Institute of Murcia , Murcia , Spain
| | - Carlos M Martinez
- Pathology Unit, Biomedical Research Institute of Murcia , Murcia , Spain
| | - Virginia Reverte
- Department of Physiology, School of Medicine, University of Murcia and Biomedical Research Institute of Murcia , Murcia , Spain
| | - Lidia Oltra
- Department of Physiology, School of Medicine, University of Murcia and Biomedical Research Institute of Murcia , Murcia , Spain
| | - Maria Teresa Llinas
- Department of Physiology, School of Medicine, University of Murcia and Biomedical Research Institute of Murcia , Murcia , Spain
| | - Francisco Javier Salazar
- Department of Physiology, School of Medicine, University of Murcia and Biomedical Research Institute of Murcia , Murcia , Spain
| |
Collapse
|
6
|
Marques-Oliveira GH, Silva TM, Lima WG, Valadares HMS, Chaves VE. Insulin as a hormone regulator of the synthesis and release of leptin by white adipose tissue. Peptides 2018; 106:49-58. [PMID: 29953915 DOI: 10.1016/j.peptides.2018.06.007] [Citation(s) in RCA: 18] [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: 03/13/2018] [Revised: 06/20/2018] [Accepted: 06/24/2018] [Indexed: 02/09/2023]
Abstract
Leptin and its receptor are widely distributed in several tissues, mainly in white adipose tissue. The serum leptin is highly correlated with body mass index in rodents and humans, being documented that leptin levels reduces in the fasting state and increase during refeeding, similarly to insulin release by pancreatic islets. Insulin appears to increase leptin mRNA and protein expression and its release by adipocytes. Some studies have suggested that insulin acts through the activation of the transcription factors: sterol regulatory element binding protein 1 (SREBP1), CCAAT enhancer binding protein-α (C/EBP-α) and specificity protein 1 (Sp1). Insulin stimulates the release of preformed and newly synthesized leptin by adipocytes through its signaling cascade. Its effects are blocked by inhibitors of the insulin signaling pathway, as well as by inhibitors of protein synthesis and agents that increase the intracellular cAMP. The literature data suggest that chronic hyperinsulinemia increases serum leptin levels in humans and rodents. In this review, we summarized the most updated knowledge on the effects of insulin on serum leptin levels, presenting the cell mechanisms that control leptin synthesis and release by the white adipose tissue.
Collapse
Affiliation(s)
| | - Thaís Marques Silva
- Laboratory of Physiology, Federal University of São João del-Rei, Divinópolis, Minas Gerais, Brazil
| | - William Gustavo Lima
- Laboratory of Physiology, Federal University of São João del-Rei, Divinópolis, Minas Gerais, Brazil
| | | | - Valéria Ernestânia Chaves
- Laboratory of Physiology, Federal University of São João del-Rei, Divinópolis, Minas Gerais, Brazil.
| |
Collapse
|
7
|
Altered Feeding Behaviors and Adiposity Precede Observable Weight Gain in Young Rats Submitted to a Short-Term High-Fat Diet. J Nutr Metab 2018; 2018:1498150. [PMID: 29805802 PMCID: PMC5901484 DOI: 10.1155/2018/1498150] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 02/28/2018] [Indexed: 12/20/2022] Open
Abstract
Information regarding the early effects of obesogenic diets on feeding patterns and behaviors is limited. To improve knowledge regarding the etiology of obesity, young male Wistar rats were submitted to high-fat (HFD) or regular chow diets (RCDs) for 14 days. Various metabolic parameters were continuously measured using metabolic chambers. Total weight gain was similar between groups, but heavier visceral fat depots and reduced weight of livers were found in HFD rats. Total calorie intake was increased while individual feeding bouts were shorter and of higher calorie intake in response to HFD. Ambulatory activity and sleep duration were decreased in HFD rats during passive and active phase, respectively. Acylated and unacylated ghrelin levels were unaltered by the increased calorie intake and the early changes in body composition. This indicates that at this early stage, the orexigenic signal did not adapt to the high-calorie content of HFD. We hereby demonstrate that, although total weight gain is not affected, a short-term obesogenic diet alters body composition, feeding patterns, satiation, ambulatory activity profiles, and behaviours in a young rat model. Moreover, this effect precedes changes in weight gain, obesity, and ensuing metabolic disorders.
Collapse
|
8
|
Role of cannabinoid receptor type 1 in rostral ventrolateral medulla in high-fat diet-induced hypertension in rats. J Hypertens 2018; 36:801-808. [PMID: 29493561 DOI: 10.1097/hjh.0000000000001621] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Stimulation of cannabinoid type 1 (CB1) receptor in the rostral ventrolateral medulla (RVLM) increases renal sympathetic activity (RSNA) and blood pressure (BP) in rats. Thus, we hypothesized that CB1 receptor in the RVLM may play a critical role in the development of obesity-induced hypertension. METHODS To this end, we evaluated the levels of endocannabinoids and CB1 receptors in the RVLM in high-fat diet (HFD)-induced hypertensive rats. We then used pharmacological and molecular methods to examine the role of RVLM CB1 receptors in regulation of BP, heart rate (HR), and RSNA in obesity-induced hypertensive rats. RESULTS We found that HFD-fed rats exhibited higher basal BP, HR, and RSNA than standard diet-fed rats, which were associated with increased levels of endocannabinoids and CB1 receptor expression in the RVLM. Furthermore, unilateral intra-RVLM microinjections of AM251 (0, 100, or 500 nM/0.5 μl/site) dose-dependently decreased BP, HR, and RSNA to a greater extent in HFD-fed rats than in standard diet-fed rats. Finally, siRNA-mediated knockdown of CB1 receptor expression in the RVLM robustly decreased BP, HR, and RSNA in HFD-fed rats. CONCLUSION Taken together, our results suggested that enhanced CB1 receptor-mediated neurotransmissions in the RVLM may play a role in the development of obesity-induced hypertension.
Collapse
|
9
|
Increased susceptibility of post-weaning rats on high-fat diet to metabolic syndrome. J Adv Res 2017; 8:743-752. [PMID: 29062573 PMCID: PMC5645161 DOI: 10.1016/j.jare.2017.10.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Revised: 10/06/2017] [Accepted: 10/07/2017] [Indexed: 01/11/2023] Open
Abstract
The present study aimed to examine the effects of the types of high-calorie diets (high-fat and high-fat-high-sucrose diets) and two different developmental stages (post-weaning and young adult) on the induction of metabolic syndrome. Male, post-weaning and adult (3- and 8-week old, respectively) Sprague Dawley rats were given control, high-fat (60% kcal), and high-fat-high-sucrose (60% kcal fat + 30% sucrose water) diets for eight weeks (n = 6 to 7 per group). Physical, biochemical, and transcriptional changes as well as liver histology were noted. Post-weaning rats had higher weight gain, abdominal fat mass, fasting glucose, high density lipoprotein cholesterol, faster hypertension onset, but lower circulating advanced glycation end products compared to adult rats. This is accompanied by upregulation of peroxisome proliferator-activated receptor (PPAR) α and γ in the liver and receptor for advanced glycation end products (RAGE) in the visceral adipose tissue. Post-weaning rats on high-fat diet manifested all phenotypes of metabolic syndrome and increased hepatic steatosis, which are linked to increased hepatic and adipocyte PPARγ expression. Adult rats on high-fat-high-sucrose diet merely became obese and hypertensive within the same treatment duration. Thus, it is more effective and less time-consuming to induce metabolic syndrome in male post-weaning rats with high-fat diet compared to young adult rats. As male rats were selectively included into the study, the results may not be generalisable to all post-weaning rats and further investigation on female rats is required.
Collapse
|
10
|
Sleeve Gastrectomy Decreases Body Weight, Whole-Body Adiposity, and Blood Pressure Even in Aged Diet-Induced Obese Rats. Obes Surg 2017; 26:1549-58. [PMID: 26439733 DOI: 10.1007/s11695-015-1919-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Aging and obesity are two conditions associated with increased risk of cardiovascular disease. Our aim was to analyze whether an advanced age affects the beneficial effects of sleeve gastrectomy on weight loss and blood pressure in an experimental model of diet-induced obesity (DIO). METHODS Young (6-month-old) and old (18-month-old) male Wistar DIO rats (n = 101) were subjected to surgical (sham operation and sleeve gastrectomy) or dietary interventions (pair-fed to the amount of food eaten by sleeve gastrectomized animals). Systolic (SBP), diastolic (DBP), and mean (MBP) blood pressure values and heart rate (HR) were recorded in conscious, resting animals by non-invasive tail-cuff plethysmography before and 4 weeks after surgical or dietary interventions. RESULTS Aging was associated with higher (P < 0.05) body weight and subcutaneous and perirenal fat mass as well as mild cardiac hypertrophy. Sleeve gastrectomy induced a reduction in body weight, whole-body adiposity, and serum total ghrelin in both young and old DIO rats. The younger group achieved a higher excess weight loss than the older group (164 ± 60 vs. 82 ± 17 %, P < 0.05). A significant (P < 0.05) decrease in insulin resistance, SBP, DBP, MBP, and HR without changes in heart weight was observed after sleeve gastrectomy independently of age. CONCLUSION Our results provide evidence for the effectiveness of sleeve gastrectomy without increased operative risk in body weight and blood pressure reduction even in aged animals via endocrine changes that go beyond the mere caloric restriction.
Collapse
|
11
|
Moghadam AA, Moran TH, Dailey MJ. Alterations in circadian and meal-induced gut peptide levels in lean and obese rats. Exp Biol Med (Maywood) 2017; 242:1786-1794. [PMID: 29191090 DOI: 10.1177/1535370217732041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Alterations in gut hormone signaling are a likely contributing factor to the metabolic disturbances associated with overweight/obesity as they coordinate the timing of feeding behavior, absorption, and utilization of nutrients. These hormones are released in response to food intake, or follow a circadian or anticipatory pattern of secretion that is independent of nutrient stimulation. The aim of this study was to identify the degree to which high-fat diet-induced obesity would alter the daily rhythm of gut peptide plasma levels (glucagon-like peptide-1 [GLP-1], peptide YY [PYY], insulin or amylin [AMY]) or meal-induced levels in the middle of the light or dark cycle. Male Sprague-Dawley rats were fed a high-fat diet (OBESE) or chow (LEAN), implanted with jugular catheters, and blood samples were taken every 2 h throughout the light/dark cycle while freely feeding or after an Ensure liquid meal. We found that even when OBESE and LEAN animals ate the same kcals and have a similar pattern of food intake, there is a difference in both the levels and rhythm of plasma gut peptides. GLP-1 and PYY are higher during the light cycle in LEAN animals and AMY is higher in the OBESE group throughout the light/dark cycle. There was also a differential response of plasma gut signals after the Ensure meal, even though the composition and amount of intake of the meal were the same in both groups. These changes occur prior to the high-fat diet induced loss of glycemic control and may be a target for early intervention. Impact statement The aim of this study was to test if obesity would alter the daily rhythm of gut peptides or meal-induced levels in the middle of the light or dark cycle. We found that even when animals are eating the same amount (in kcal) of food that the obese animals have altered daily rhythms and meal-induced gut peptide levels. In particular, we are the first to show that obesity induces increases in peptide YY levels during the light cycle and amylin remains high throughout the light and dark cycle in obese animals. These changes occurred prior to a loss of glycemic control. Thus, the rhythm of gut peptides could be used as an early indicator of later and more serious metabolic disturbances and may be a target for early intervention.
Collapse
Affiliation(s)
- Alexander A Moghadam
- 1 Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY 10591, USA
| | - Timothy H Moran
- 2 Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Megan J Dailey
- 3 Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| |
Collapse
|
12
|
Toklu HZ, Scarpace PJ, Sakarya Y, Kirichenko N, Matheny M, Bruce EB, Carter CS, Morgan D, Tümer N. Intracerebroventricular tempol administration in older rats reduces oxidative stress in the hypothalamus but does not change STAT3 signalling or SIRT1/AMPK pathway. Appl Physiol Nutr Metab 2016; 42:59-67. [PMID: 28006433 DOI: 10.1139/apnm-2016-0067] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Hypothalamic inflammation and increased oxidative stress are believed to be mechanisms that contribute to obesity. 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (tempol), a free radical scavenger, has been shown to reduce inflammation and oxidative stress. We hypothesized that brain infusion of tempol would reduce oxidative stress, and thus would reduce food intake and body weight and improve body composition in rats with age-related obesity and known elevated oxidative stress. Furthermore, we predicted an associated increase in markers of leptin signalling, including the silent mating type information regulator 2 homolog 1 (SIRT1)/5'AMP-activated protein kinase (AMPK) pathway and the signal transducer and activator of transcription 3 (STAT3) pathway. For this purpose, osmotic minipumps were placed in the intracerebroventricular region of young (3 months) and aged (23 months) male Fischer 344 x Brown Norway rats for the continuous infusion of tempol or vehicle for 2 weeks. Tempol significantly decreased (p < 0.01) nicotinamide adenine dinucleotide phosphate oxidase activity in the hypothalamus but failed to reduce food intake or weight gain and did not alter body composition. SIRT1 activity and Acetyl p53 were decreased and phosphorylation of AMPK was increased with age, but they were unchanged with tempol. Basal phosphorylation of STAT3 was unchanged with age or tempol. These results indicate that tempol decreases oxidative stress but fails to alter feeding behaviour, body weight, or body composition. Moreover, tempol does not modulate the SIRT1/AMPK/p53 pathway and does not change leptin signalling. Thus, a reduction in hypothalamic oxidative stress is not sufficient to reverse age-related obesity.
Collapse
Affiliation(s)
- Hale Z Toklu
- a Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA.,b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Philip J Scarpace
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Yasemin Sakarya
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Nataliya Kirichenko
- a Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA.,b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Michael Matheny
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Erin B Bruce
- b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| | - Christy S Carter
- c Department of Aging and Geriatric Research, University of Florida, Gainesville, FL 32610, USA
| | - Drake Morgan
- d Department of Psychiatry, University of Florida, Gainesville, FL 32610, USA
| | - Nihal Tümer
- a Geriatric Research Education and Clinical Center, Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL 32608, USA.,b Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL 32610, USA
| |
Collapse
|
13
|
Bussey CE, Withers SB, Aldous RG, Edwards G, Heagerty AM. Obesity-Related Perivascular Adipose Tissue Damage Is Reversed by Sustained Weight Loss in the Rat. Arterioscler Thromb Vasc Biol 2016; 36:1377-85. [DOI: 10.1161/atvbaha.116.307210] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 04/26/2016] [Indexed: 11/16/2022]
Affiliation(s)
- Charlotte E. Bussey
- From the Institute of Cardiovascular Sciences (C.E.B., S.B.W., R.G.A., A.M.H.), and Faculty of Life Sciences (G.E.), University of Manchester, Manchester, United Kingdom
| | - Sarah B. Withers
- From the Institute of Cardiovascular Sciences (C.E.B., S.B.W., R.G.A., A.M.H.), and Faculty of Life Sciences (G.E.), University of Manchester, Manchester, United Kingdom
| | - Robert G. Aldous
- From the Institute of Cardiovascular Sciences (C.E.B., S.B.W., R.G.A., A.M.H.), and Faculty of Life Sciences (G.E.), University of Manchester, Manchester, United Kingdom
| | - Gillian Edwards
- From the Institute of Cardiovascular Sciences (C.E.B., S.B.W., R.G.A., A.M.H.), and Faculty of Life Sciences (G.E.), University of Manchester, Manchester, United Kingdom
| | - Anthony M. Heagerty
- From the Institute of Cardiovascular Sciences (C.E.B., S.B.W., R.G.A., A.M.H.), and Faculty of Life Sciences (G.E.), University of Manchester, Manchester, United Kingdom
| |
Collapse
|
14
|
Toklu HZ, Muller-Delp J, Sakaraya Y, Oktay S, Kirichenko N, Matheny M, Carter CS, Morgan D, Strehler KYE, Tumer N, Scarpace PJ. High dietary fructose does not exacerbate the detrimental consequences of high fat diet on basilar artery function. JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY : AN OFFICIAL JOURNAL OF THE POLISH PHYSIOLOGICAL SOCIETY 2016; 67:205-216. [PMID: 27226180 PMCID: PMC5572808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 03/29/2016] [Indexed: 06/05/2023]
Abstract
The objective of the study was to determine the effects of a high fat (HF) diet alone or with high fructose (HF/F) on functional and structural changes in the basilar arteries and cardiovascular health parameters in rats. Male Sprague Dawley rats were fed either a HF (30%) or HF/F (30/40%) diet for 12 weeks. The basilar artery was cannulated in a pressurized system (90 cm H2O) and vascular responses to KCl (30 - 120 mM), endothelin (10(-11) - 10(-7) M), acetylcholine (ACh) (10(-10) - 10(-4) M), diethylamine (DEA)-NONO-ate (10(-10) - 10(-4) M), and papaverine (10(-10) - 10(-4) M) were evaluated. Rats were also monitored for food intake, body weight, blood lipids, blood pressure, and heart rate. At death, asymmetrical dimethyl arginine level (ADMA) and leptin were assayed in serum. Although there was no significant difference in weight gain and food intake, HF and HF/F diets increased body fat composition and decreased the lean mass. HF/F diet accelerated the development of dyslipidemia. Although resting blood pressure remained unchanged, stress caused a significant elevation in blood pressure and a modest increase in heart rate in HF fed rats. Both HF and HF/F diet resulted in decreased response to endothelium-dependent and -independent relaxation, whereas increased basilar artery wall thickness was observed only in HF group. Serum leptin levels positively correlated with wall thickness. Moreover serum ADMA was increased and eNOS immunofluorescence was significantly decreased with both diets. These data suggest that the presence of high fructose in a HF diet does not exacerbate the detrimental consequences of a HF diet on basilar artery function.
Collapse
Affiliation(s)
- H Z Toklu
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - J Muller-Delp
- Department of Biomedical Sciences, Florida State University, Tallahassee, FL, USA
| | - Y Sakaraya
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - S Oktay
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
- School of Dentistry, Marmara University, Istanbul, Turkey
| | - N Kirichenko
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - M Matheny
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - C S Carter
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL, USA
| | - D Morgan
- Department of Psychiatry, University of Florida, Gainesville, FL, USA
| | - K Y E Strehler
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
| | - N Tumer
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA
- North Florida/South Georgia Veterans Health System, Geriatric Research, Education, and Clinical Center, Gainesville, FL, USA
| | - P J Scarpace
- Department of Pharmacology and Therapeutics, University of Florida, Gainesville, FL, USA.
| |
Collapse
|
15
|
Speretta GF, Silva AA, Vendramini RC, Zanesco A, Delbin MA, Menani JV, Bassi M, Colombari E, Colombari DSA. Resistance training prevents the cardiovascular changes caused by high-fat diet. Life Sci 2016; 146:154-62. [PMID: 26776833 DOI: 10.1016/j.lfs.2016.01.011] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 12/04/2015] [Accepted: 01/07/2016] [Indexed: 12/31/2022]
Abstract
AIMS Aerobic exercise is indicated for prevention and treatment of obesity-induced cardiovascular disorders. Although the resistance training (RT) may also produce effects similar to aerobic exercise, this is not completely clear yet. In the present study, we tested if RT in moderate intensity might prevent alterations in blood pressure (BP), sympathetic modulation of systolic blood pressure (SBP), baroreflex function and the changes in renin-angiotensin system (RAS) and cytokines mRNA expression within the nucleus of the tract solitary (NTS) in rats fed with high-fat diet (HFD). MAIN METHODS Male Holtzman rats (300-320 g) were divided into 4 groups: sedentary with standard chow diet (SED-SD); sedentary with high-fat diet (SED-HFD); RT with standard chow diet (RT-SD); and RT with high-fat diet (RT-HFD). The trained groups performed a total of 10 weeks of moderate intensity RT in a vertical ladder. In the first 3 weeks all experimental groups were fed with SD. In the next 7 weeks, the SED-HFD and RT-HFD groups were fed with HFD. KEY FINDINGS In SED-HFD, BP and sympathetic modulation of SBP increased, whereas baroreflex bradycardic responses were attenuated. RT prevented the cardiovascular and inflammatory responses (increases in tumoral necrosis factor-α and interleukin-1β) produced by HFD in SED rats. The anti-inflammatory interleukin-10, angiotensin type 2 receptor, Mas receptor and angiotensin converting enzyme 2 mRNA expressions in the NTS increased in the RT-HFD compared to SED-HFD. SIGNIFICANCE The data demonstrated that moderate intensity RT prevented obesity-induced cardiovascular disorders simultaneously with reduced inflammatory responses and modifications of RAS in the NTS.
Collapse
Affiliation(s)
- Guilherme F Speretta
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - André A Silva
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Regina C Vendramini
- Department of Clinical Analysis, School of Pharmaceutical Sciences, UNESP, Araraquara, SP, Brazil
| | - Angelina Zanesco
- Department of Physical Education, Institute of Bioscience, UNESP, Rio Claro, SP, Brazil
| | - Maria A Delbin
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - José V Menani
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Mirian Bassi
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Eduardo Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil
| | - Débora S A Colombari
- Department of Physiology and Pathology, School of Dentistry, São Paulo State University (UNESP), Araraquara, SP, Brazil.
| |
Collapse
|
16
|
Murotomi K, Umeno A, Yasunaga M, Shichiri M, Ishida N, Koike T, Matsuo T, Abe H, Yoshida Y, Nakajima Y. Oleuropein-Rich Diet Attenuates Hyperglycemia and Impaired Glucose Tolerance in Type 2 Diabetes Model Mouse. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:6715-22. [PMID: 26165358 DOI: 10.1021/acs.jafc.5b00556] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Oleuropein, a phenolic compound found in abundance in olive leaves, has beneficial effects on various diseases. However, it is unknown whether an oleuropein-rich diet is efficacious against type 2 diabetic phenotypes. In this study, we investigated the effects of the oleuropein-containing supplement OPIACE, whose oleuropein content exceeds 35% (w/w), on the diabetic phenotypes in type 2 diabetes model Tsumura Suzuki Obese Diabetes (TSOD) mouse. TSOD mice were fed OPIACE at 4 weeks of age, i.e., before the TSOD mice exhibited diabetic phenotypes. We revealed that OPIACE attenuated hyperglycemia and impaired glucose tolerance in TSOD mice over the long-term (from 10 to 24 weeks of age) but had no effect on obesity. Furthermore, we demonstrated that OPIACE mildly reduced oxidative stress in TSOD mice by 26.2% and attenuated anxiety-like behavioral abnormality in aged TSOD mice. The results suggest that oleuropein suppresses the progression of type 2 diabetes and diabetes-related behavioral abnormality over the long-term.
Collapse
Affiliation(s)
- Kazutoshi Murotomi
- †Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Aya Umeno
- †Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Mayu Yasunaga
- †Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Mototada Shichiri
- ‡Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka 563-8577, Japan
| | - Noriko Ishida
- ‡Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Ikeda, Osaka 563-8577, Japan
| | | | | | - Hiroko Abe
- †Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Yasukazu Yoshida
- †Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| | - Yoshihiro Nakajima
- †Health Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Takamatsu, Kagawa 761-0395, Japan
| |
Collapse
|
17
|
Zhao LY, Li J, Yuan F, Li M, Zhang Q, Huang YY, Pang JY, Zhang B, Sun FY, Sun HS, Li Q, Cao L, Xie Y, Lin YC, Liu J, Tan HM, Wang GL. Xyloketal B attenuates atherosclerotic plaque formation and endothelial dysfunction in apolipoprotein e deficient mice. Mar Drugs 2015; 13:2306-26. [PMID: 25874925 PMCID: PMC4413213 DOI: 10.3390/md13042306] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 03/30/2015] [Accepted: 04/03/2015] [Indexed: 12/31/2022] Open
Abstract
Our previous studies demonstrated that xyloketal B, a novel marine compound with a unique chemical structure, has strong antioxidant actions and can protect against endothelial injury in different cell types cultured in vitro and model organisms in vivo. The oxidative endothelial dysfunction and decrease in nitric oxide (NO) bioavailability are critical for the development of atherosclerotic lesion. We thus examined whether xyloketal B had an influence on the atherosclerotic plaque area in apolipoprotein E-deficient (apoE-/-) mice fed a high-fat diet and investigated the underlying mechanisms. We found in our present study that the administration of xyloketal B dose-dependently decreased the atherosclerotic plaque area both in the aortic sinus and throughout the aorta in apoE-/- mice fed a high-fat diet. In addition, xyloketal B markedly reduced the levels of vascular oxidative stress, as well as improving the impaired endothelium integrity and NO-dependent aortic vasorelaxation in atherosclerotic mice. Moreover, xyloketal B significantly changed the phosphorylation levels of endothelial nitric oxide synthase (eNOS) and Akt without altering the expression of total eNOS and Akt in cultured human umbilical vein endothelial cells (HUVECs). Here, it increased eNOS phosphorylation at the positive regulatory site of Ser-1177, while inhibiting phosphorylation at the negative regulatory site of Thr-495. Taken together, these findings indicate that xyloketal B has dramatic anti-atherosclerotic effects in vivo, which is partly due to its antioxidant features and/or improvement of endothelial function.
Collapse
MESH Headings
- Animals
- Antioxidants/adverse effects
- Antioxidants/pharmacology
- Antioxidants/therapeutic use
- Aorta/drug effects
- Aorta/metabolism
- Aorta/physiopathology
- Aorta/ultrastructure
- Apolipoproteins E/deficiency
- Apolipoproteins E/metabolism
- Cardiovascular Agents/adverse effects
- Cardiovascular Agents/pharmacology
- Cardiovascular Agents/therapeutic use
- Cells, Cultured
- Diet, High-Fat/adverse effects
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiopathology
- Endothelium, Vascular/ultrastructure
- Human Umbilical Vein Endothelial Cells/cytology
- Human Umbilical Vein Endothelial Cells/drug effects
- Human Umbilical Vein Endothelial Cells/metabolism
- Humans
- Lipid Metabolism, Inborn Errors/drug therapy
- Lipid Metabolism, Inborn Errors/metabolism
- Lipid Metabolism, Inborn Errors/pathology
- Lipid Metabolism, Inborn Errors/physiopathology
- Male
- Mice, Knockout
- Nitric Oxide Synthase Type III/genetics
- Nitric Oxide Synthase Type III/metabolism
- Oxidative Stress/drug effects
- Phosphorylation/drug effects
- Plaque, Atherosclerotic/etiology
- Plaque, Atherosclerotic/prevention & control
- Protein Processing, Post-Translational/drug effects
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Pyrans/adverse effects
- Pyrans/pharmacology
- Pyrans/therapeutic use
- Specific Pathogen-Free Organisms
- Vasodilation/drug effects
Collapse
Affiliation(s)
- Li-Yan Zhao
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (L.-Y.Z.); (F.Y.); (Y.X.); (J.L.)
| | - Jie Li
- Department of Anesthesiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510080, China; E-Mail:
| | - Feng Yuan
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (L.-Y.Z.); (F.Y.); (Y.X.); (J.L.)
| | - Mei Li
- VIP Healthcare Center, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, China; E-Mail:
| | - Quan Zhang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (Q.Z.); (Q.L.); (L.C.)
| | - Yun-Ying Huang
- Department of Pharmacy, The fifth Affiliated Hospital of Guangzhou Medical University, Guangzhou 510182, China; E-Mail:
| | - Ji-Yan Pang
- Department of Applied Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (J.-Y.P.); (Y.-C.L.)
- Department of Education of Guangdong Province, Guangdong Province Key Laboratory of Functional Molecules in Oceanic Microorganism, Sun Yat-sen University, Guangzhou 510080, China
| | - Bin Zhang
- Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangzhou 510080, China; E-Mail:
| | - Fang-Yun Sun
- Lab for Basic Research of Life Science, School of Medicine, Tibet Institute for Nationalities, Xianyang 712082, China; E-Mails:
| | - Hong-Shuo Sun
- Departments of Surgery and Physiology, Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON M5G 1G6, Canada; E-Mail:
| | - Qian Li
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (Q.Z.); (Q.L.); (L.C.)
| | - Lu Cao
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (Q.Z.); (Q.L.); (L.C.)
| | - Yu Xie
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (L.-Y.Z.); (F.Y.); (Y.X.); (J.L.)
| | - Yong-Cheng Lin
- Department of Applied Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (J.-Y.P.); (Y.-C.L.)
- Department of Education of Guangdong Province, Guangdong Province Key Laboratory of Functional Molecules in Oceanic Microorganism, Sun Yat-sen University, Guangzhou 510080, China
| | - Jie Liu
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (L.-Y.Z.); (F.Y.); (Y.X.); (J.L.)
| | - Hong-Mei Tan
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (Q.Z.); (Q.L.); (L.C.)
- Department of Education of Guangdong Province, Guangdong Province Key Laboratory of Functional Molecules in Oceanic Microorganism, Sun Yat-sen University, Guangzhou 510080, China
- Authors to whom correspondence should be addressed; E-Mails: (H.-M.T.); (G.-L.W.); Tel./Fax: +86-020-8733-4055 (H.-M.T.); Tel.: +86-020-8733-0300 (G.-L.W.); Fax: +86-020-8733-1155 (G.-L.W.)
| | - Guan-Lei Wang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China; E-Mails: (L.-Y.Z.); (F.Y.); (Y.X.); (J.L.)
- Department of Education of Guangdong Province, Guangdong Province Key Laboratory of Functional Molecules in Oceanic Microorganism, Sun Yat-sen University, Guangzhou 510080, China
- Authors to whom correspondence should be addressed; E-Mails: (H.-M.T.); (G.-L.W.); Tel./Fax: +86-020-8733-4055 (H.-M.T.); Tel.: +86-020-8733-0300 (G.-L.W.); Fax: +86-020-8733-1155 (G.-L.W.)
| |
Collapse
|
18
|
Dake BL, Oltman CL. Cardiovascular, metabolic, and coronary dysfunction in high-fat-fed obesity-resistant/prone rats. Obesity (Silver Spring) 2015; 23:623-9. [PMID: 25645537 DOI: 10.1002/oby.21009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 11/28/2014] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Obesity is a global epidemic leading to several comorbidities including diabetes and cardiovascular disease. The hypothesis that the genetic background of the obesity-prone rat (OP) predisposes to physiologic, metabolic, and microvascular dysfunction which is exacerbated by a diet high in saturated fats was tested. METHODS Male OP and obesity-resistant (OR) rats were fed either a diet containing 10% (chow) or 45% kcal fat (HF) for 42 weeks. RESULTS Weight of OP rats was greater than OR rats by 8 weeks on both diets. Blood pressure was increased in OP rats on chow and further augmented by HF diet compared to OR rats on similar diets. In contrast to weight and blood pressure, glucose clearance was similar in OR and OP rats on chow and impaired in both models on HF diet. Relaxation to acetylcholine was attenuated in OP rats compared to OR rats by 8 weeks and remained reduced throughout the study. A longer period of time was required to observe vascular dysfunction in HF-fed OR rats. CONCLUSIONS When compared to OR rats, OP rats are prone to develop not only greater obesity but also hypertension and vascular dysfunction on a normal diet which is further augmented with HF diet.
Collapse
Affiliation(s)
- Brian L Dake
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa and the Iowa City Veterans Affairs Health Care System, Iowa City, Iowa, USA
| | | |
Collapse
|
19
|
Kleinschmidt TL, Oltman CL. Progression and reversal of coronary and mesenteric vascular dysfunction associated with obesity. Obesity (Silver Spring) 2014; 22:2193-200. [PMID: 25044654 DOI: 10.1002/oby.20837] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/28/2014] [Accepted: 06/22/2014] [Indexed: 02/04/2023]
Abstract
OBJECTIVE The purpose of this study was to examine progression and reversal of microvascular complications when rats were fed a high fat diet. METHODS Sprague-Dawley rats 10 weeks of age were fed a diet containing 45% kcal fat for up to 32 weeks. Blood pressure and heart rate was measured by telemetry. Vascular reactivity of aorta and small coronary and mesenteric vessels was determined after 8, 16, 24, and 32 weeks on diet. RESULTS There was a modest increase in weight and blood pressure in high fat fed rats. Sodium nitroprusside (SNP)-induced relaxation of coronary arteries was potentiated after 8 weeks on high fat diet, however, this enhanced response was not observed after 16, 24, or 32 weeks of diet. Acetylcholine (Ach) mediated relaxation was attenuated after 16, 24, and 32 weeks of high fat diet in coronary arteries; however, in aorta and mesenteric arteries, Ach-mediated response was not altered until 32 weeks on high fat diet. Reversing the high fat diet for 8 weeks resulted in partial recovery of metabolic parameters; however endothelial function in coronary arteries remained impaired. CONCLUSIONS These studies indicate that high fat diet promotes progressive impairment of coronary vascular function that is difficult to reverse.
Collapse
Affiliation(s)
- Travis L Kleinschmidt
- Department of Internal Medicine, University of Iowa and the Iowa City Veterans Affairs Health Care System, Iowa City, Iowa, USA
| | | |
Collapse
|
20
|
van Waveren A, Duncan MJ, Coulson FR, Fenning A. Moderate intensity physical activity prevents increased blood glucose concentrations, fat pad deposition and cardiac action potential prolongation following diet-induced obesity in a juvenile-adolescent rat model. BMC OBESITY 2014. [PMID: 26217503 PMCID: PMC4511067 DOI: 10.1186/2052-9538-1-11] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Background Both obesity and a lack of physical activity have been associated with an elevated risk of cardiovascular disease (CVD). The incidence of obesity is increasing, especially in juvenile-adolescents. While there is limited research examining the chronic effects of obesity in adolescent humans and animal models of this condition, little is also known concerning how moderate physical activity might prevent or attenuate secondary cardiovascular complications induced by obesity during adolescence. We investigated the effects of diet-induced obesity (consisting of a high-fat, high-carbohydrate diet (HFHC)) on biometric indices, vascular and airway function, cardiovascular function, systemic oxidative stress and markers of inflammation in a juvenile-adolescent rodent model. Four groups were used: control (CON), physical activity (PA) treated, HFHC and HFHC + PA (n = 16 per group). HFHC feeding started at 4 weeks of age for a period of 12 weeks. Physical activity treatment was initiated (PA and HFHC + PA groups) when the animals were 8 weeks of age, for 8 weeks. Results Physical activity in juvenile-adolescent healthy rats showed no change in comparison to the CON group in all experimental parameters except for increases in lipid peroxidation, decreases in inflammatory cytokines, improvements in vascular reactivity and decreased atrial responses to positive chronotropic agents. The HFHC animals were mildly hyperglycemic, hypertensive, displayed renal hypertrophy and showed increased retroperitoneal fat pad deposition compared to the CON group. HFHC + PA rats were also hypertensive, however showed improvements in cardiac electrophysiology, body weight, fat pad deposition and inflammatory signaling, in comparison to the HFHC fed rats and CON animals. Conclusion In conclusion, in a juvenile-adolescent animal model of diet-induced obesity engagement in physical activity is beneficial in reducing the inflammatory effects of obesity.
Collapse
Affiliation(s)
- Alannah van Waveren
- Central Queensland University, Institute of Health and Social Science Research, Rockhampton, Queensland 4702 Australia
| | - Mitch J Duncan
- School of Medicine & Public Health, Priority Research Centre in Physical Activity and Nutrition, The University of Newcastle, Newcastle, Australia
| | - Fiona R Coulson
- School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland 4702 Australia
| | - Andrew Fenning
- Central Queensland University, Institute of Health and Social Science Research, Rockhampton, Queensland 4702 Australia ; School of Medical and Applied Sciences, Central Queensland University, Rockhampton, Queensland 4702 Australia
| |
Collapse
|
21
|
Du J, Fan LM, Mai A, Li JM. Crucial roles of Nox2-derived oxidative stress in deteriorating the function of insulin receptors and endothelium in dietary obesity of middle-aged mice. Br J Pharmacol 2014; 170:1064-77. [PMID: 23957783 DOI: 10.1111/bph.12336] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 08/05/2013] [Accepted: 08/08/2013] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND AND PURPOSE Systemic oxidative stress associated with dietary calorie overload plays an important role in the deterioration of vascular function in middle-aged patients suffering from obesity and insulin resistance. However, effective therapy is still lacking. EXPERIMENTAL APPROACH In this study, we used a mouse model of middle-aged obesity to investigate the therapeutic potential of pharmaceutical inhibition (apocynin, 5 mM supplied in the drinking water) or knockout of Nox2, an enzyme generating reactive oxygen species (ROS), in high-fat diet (HFD)-induced obesity, oxidative stress, insulin resistance and endothelial dysfunction. Littermates of C57BL/6J wild-type (WT) and Nox2 knockout (KO) mice (7 months old) were fed with a HFD (45% kcal fat) or normal chow diet (NCD, 12% kcal fat) for 16 weeks and used at 11 months of age. KEY RESULTS Compared to NCD WT mice, HFD WT mice developed obesity, insulin resistance, dyslipidaemia and hypertension. Aortic vessels from these mice showed significantly increased Nox2 expression and ROS production, accompanied by significantly increased ERK1/2 activation, reduced insulin receptor expression, decreased Akt and eNOS phosphorylation and impaired endothelium-dependent vessel relaxation to acetylcholine. All these HFD-induced abnormalities (except the hyperinsulinaemia) were absent in apocynin-treated WT or Nox2 KO mice given the same HFD. CONCLUSIONS AND IMPLICATIONS In conclusion, Nox2-derived ROS played a key role in damaging insulin receptor and endothelial function in dietary obesity after middle-age. Targeting Nox2 could represent a valuable therapeutic strategy in the metabolic syndrome.
Collapse
Affiliation(s)
- Junjie Du
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | | | | | | |
Collapse
|
22
|
Daulatzai MA. Chronic functional bowel syndrome enhances gut-brain axis dysfunction, neuroinflammation, cognitive impairment, and vulnerability to dementia. Neurochem Res 2014; 39:624-44. [PMID: 24590859 DOI: 10.1007/s11064-014-1266-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 02/10/2014] [Accepted: 02/25/2014] [Indexed: 12/15/2022]
Abstract
The irritable bowel syndrome (IBS) is a common chronic functional gastrointestinal disorder world wide that lasts for decades. The human gut harbors a diverse population of microbial organisms which is symbiotic and important for well being. However, studies on conventional, germ-free, and obese animals have shown that alteration in normal commensal gut microbiota and an increase in pathogenic microbiota-termed "dysbiosis", impact gut function, homeostasis, and health. Diarrhea, constipation, visceral hypersensitivity, and abdominal pain arise in IBS from the gut-induced dysfunctional metabolic, immune, and neuro-immune communication. Dysbiosis in IBS is associated with gut inflammation. Gut-related inflammation is pivotal in promoting endotoxemia, systemic inflammation, and neuroinflammation. A significant proportion of IBS patients chronically consume alcohol, non-steroidal anti-inflammatories, and fatty diet; they may also suffer from co-morbid respiratory, neuromuscular, psychological, sleep, and neurological disorders. The above pathophysiological substrate is underpinned by dysbiosis, and dysfunctional bidirectional "Gut-Brain Axis" pathways. Pathogenic gut microbiota-related systemic inflammation (due to increased lipopolysaccharide and pro-inflammatory cytokines, and barrier dysfunction), may trigger neuroinflammation enhancing dysfunctional brain regions including hippocampus and cerebellum. These as well as dysfunctional vago-vagal gut-brain axis may promote cognitive impairment. Indeed, inflammation is characteristic of a broad spectrum of neurodegenerative diseases that manifest demntia. It is argued that an awareness of pathophysiological impact of IBS and implementation of appropriate therapeutic measures may prevent cognitive impairment and minimize vulnerability to dementia.
Collapse
Affiliation(s)
- Mak Adam Daulatzai
- Sleep Disorders Group, EEE Department, Melbourne School of Engineering, The University of Melbourne, Grattan Street, 3rd Floor, Room No. 344, Parkville, VIC, 3010, Australia,
| |
Collapse
|
23
|
Bautista R, Carreón-Torres E, Luna-Luna M, Komera-Arenas Y, Franco M, Fragoso JM, López-Olmos V, Cruz-Robles D, Vargas-Barrón J, Vargas-Alarcón G, Pérez-Méndez O. Early endothelial nitrosylation and increased abdominal adiposity in Wistar rats after long-term consumption of food fried in canola oil. Nutrition 2014; 30:1055-60. [PMID: 24958674 DOI: 10.1016/j.nut.2014.01.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 01/07/2014] [Accepted: 01/11/2014] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The aim of this study was to establish whether the long-term consumption of reused canola oil contributes to the development of dyslipidemia, obesity, and endothelial function. METHODS Canola oil was used for one frying cycle (1 FC) of corn flour dough or reused 10 times (10 FC). Rats received chow diet (control) or supplemented with 7% raw oil (RO), 1 FC or 10 FC oil (n = 10 per group). Food consumption, blood pressure (BP), and body weight plasma glucose, plasma lipids were monitored. Vascular reactivity was analyzed using aorta rings stimulated with phenylephrine and acetylcholine. Nitrotyrosine presence in aorta rings was analyzed by immunohistochemistry. RESULTS After 10 wk of follow-up, visceral adipose tissue was significantly more abundant in 1 FC (7.4 ± 0.6 g) and 10 FC (8.8 ± 0.7 g) than the RO (5.0 ± 0.2 g; P = 0.05 versus 10 FC group) or control group (2.6 ± 0.3 g; P = 0.05 versus all groups). Despite similar plasma cholesterol, triglycerides, and BP among groups, a significantly reduced acetylcholine-induced vascular relaxation was observed in the three groups receiving the oil-supplemented diet (47.2% ± 3.6%, 27.2% ± 7.7%, and 25.9% ± 7.6% of relaxation, for the RO, 1 FC, and 10 FC, respectively; P < 0.05 for all versus 62.4% ± 9.7% of the control group). Endothelial dysfunction was concomitant with the presence of nitrotyrosine residues at a higher extent in the groups that received heated oils compared with the RO group. CONCLUSION High canola oil intake over 10 wk was associated with increased adipose tissue and early endothelial dysfunction probably induced by peroxinitrite formation. Such deleterious effects were significantly potentiated when the consumed oil had been used repeatedly for frying.
Collapse
Affiliation(s)
- Rocío Bautista
- Nephrology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Elizabeth Carreón-Torres
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - María Luna-Luna
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Yukari Komera-Arenas
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Martha Franco
- Nephrology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - José-Manuel Fragoso
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Victoria López-Olmos
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - David Cruz-Robles
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Jesús Vargas-Barrón
- Echocardiography Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Gilberto Vargas-Alarcón
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico
| | - Oscar Pérez-Méndez
- Molecular Biology Department, Instituto Nacional de Cardiología "Ignacio Chávez," Mexico, Distrito Federal, Mexico.
| |
Collapse
|
24
|
Rodrigues SF, Almeida-Paula LD, Granger DN. Synergistic effects of high blood cholesterol and hypertension on leukocyte and platelet recruitment in the cerebral microcirculation. Hypertension 2013; 63:747-52. [PMID: 24379186 DOI: 10.1161/hypertensionaha.113.02627] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Hypertension or hypercholesterolemia can induce a proinflammatory and prothrombogenic phenotype in the microcirculation of the brain; however, less is known about how the combination of these risk factors affects the vasculature. We recently reported that a moderate (60%) increase in plasma cholesterol blunts the recruitment of leukocytes and platelets in the cerebral microvessels elicited by hypertension. In this study, we examined whether larger increments in blood cholesterol (4-fold) exerts a similar modulating influence on the vasculature in the presence of hypertension. Apolipoprotein E-knockout mice with deoxycorticosterone acetate salt-induced hypertension were placed on a high-cholesterol diet and exhibited exaggerated leukocyte and platelet adhesion responses in cerebral microvessels. Intermittent feeding (every fourth day) with high-cholesterol diet yielded similar phenotypic changes in the vasculature. Once the mice were placed on high-cholesterol diet, 4 days on normal diet (ND) were needed to revert to a normal vascular phenotype. Angiotensin II type 1 receptors and reactive oxygen species seem to contribute to the vascular responses induced by hypercholesterolemia and hypertension. Our findings indicate that the combination of hypertension and large increases in plasma cholesterol concentration results in a severe, but reversible, inflammatory and thrombogenic phenotype in the cerebral microvasculature.
Collapse
Affiliation(s)
- Stephen F Rodrigues
- Department of Molecular and Cellular Physiology, LSU Health Sciences Center, 1501 Kings Highway, Shreveport, LA 71130-3932.
| | | | | |
Collapse
|
25
|
Jiménez-Altayó F, Onetti Y, Heras M, Dantas AP, Vila E. Western-style diet modulates contractile responses to phenylephrine differently in mesenteric arteries from senescence-accelerated prone (SAMP8) and resistant (SAMR1) mice. AGE (DORDRECHT, NETHERLANDS) 2013; 35:1219-1234. [PMID: 22777652 PMCID: PMC3705122 DOI: 10.1007/s11357-012-9450-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 06/24/2012] [Indexed: 06/01/2023]
Abstract
The influence of two known cardiovascular risk factors, aging and consumption of a high-fat diet, on vascular mesenteric artery reactivity was examined in a mouse model of accelerated senescence (SAM). Five-month-old SAM prone (SAMP8) and resistant (SAMR1) female mice were fed a Western-type high-fat diet (WD; 8 weeks). Mesenteric arteries were dissected, and vascular reactivity, protein and messenger RNA expression, superoxide anion (O 2 (·-) ) and hydrogen peroxide formation were evaluated by wire myography, immunofluorescence, RT-qPCR, ethidium fluorescence and ferric-xylenol orange, respectively. Contraction to KCl and relaxation to acetylcholine remained unchanged irrespective of senescence and diet. Although similar contractions to phenylephrine were observed in SAMR1 and SAMP8, accelerated senescence was associated with decreased eNOS and nNOS and increased O 2 (·-) synthesis. Senescence-related alterations were compensated, at least partly, by the contribution of NO derived from iNOS and the enhanced endogenous antioxidant capacity of superoxide dismutase 1 to maintain vasoconstriction. Administration of a WD induced qualitatively different alterations in phenylephrine contractions of mesenteric arteries from SAMR1 and SAMP8. SAMR1 showed increased contractions partly as a result of decreased NO availability generated by decreased eNOS and nNOS and enhanced O 2 (·-) formation. In contrast, WD feeding in SAMP8 resulted in reduced contractions due to, at least in part, the increased functional participation of iNOS-derived NO. In conclusion, senescence-dependent intrinsic alterations during early stages of vascular senescence may promote vascular adaptation and predispose to further changes in response to high-fat intake, which may lead to the progression of aging-related cardiovascular disease, whereas young subjects lack the capacity for this adaptation.
Collapse
Affiliation(s)
- Francesc Jiménez-Altayó
- Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Facultat de Medicina, Universitat Autònoma de Barcelona (UAB), 08193, Bellaterra, Cerdanyola del Vallès, Spain.
| | | | | | | | | |
Collapse
|
26
|
Tümer N, Svetlov S, Whidden M, Kirichenko N, Prima V, Erdos B, Sherman A, Kobeissy F, Yezierski R, Scarpace PJ, Vierck C, Wang KKW. Overpressure blast-wave induced brain injury elevates oxidative stress in the hypothalamus and catecholamine biosynthesis in the rat adrenal medulla. Neurosci Lett 2013; 544:62-7. [PMID: 23570732 DOI: 10.1016/j.neulet.2013.03.042] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 03/13/2013] [Accepted: 03/18/2013] [Indexed: 11/28/2022]
Abstract
Explosive overpressure brain injury (OBI) impacts the lives of both military and civilian population. We hypothesize that a single exposure to OBI results in increased hypothalamic expression of oxidative stress and activation of the sympatho-adrenal medullary axis. Since a key component of blast-induced organ injury is the primary overpressure wave, we assessed selective biochemical markers of autonomic function and oxidative stress in male Sprague Dawley rats subjected to head-directed overpressure insult. Rats were subjected to single head-directed OBI with a 358kPa peak overpressure at the target. Control rats were exposed to just noise signal being placed at ~2m distance from the shock tube nozzle. Sympathetic nervous system activation of the adrenal medullae (AM) was evaluated at 6h following blast injury by assessing the expression of catecholamine biosynthesizing enzymes, tyrosine hydroxylase (TH), dopamine-β hydroxylase (DβH), neuropeptide Y (NPY) along with plasma norepinephrine (NE). TH, DβH and NPY expression increased 20%, 25%, and 91% respectively, following OBI (P<0.05). Plasma NE was also significantly elevated by 23% (P<0.05) following OBI. OBI significantly elevated TH (49%, P<0.05) in the nucleus tractus solitarius (NTS) of the brain stem while AT1 receptor expression and NADPH oxidase activity, a marker of oxidative stress, was elevated in the hypothalamus following OBI. Collectively, the increased levels of TH, DβH and NPY expression in the rat AM, elevated TH in NTS along with increased plasma NE suggest that single OBI exposure results in increased sympathoexcitation. The mechanism may involve the elevated AT1 receptor expression and NADPH oxidase levels in the hypothalamus. Taken together, such effects may be important factors contributing to pathology of brain injury and autonomic dysfunction associated with the clinical profile of patients following OBI.
Collapse
Affiliation(s)
- Nihal Tümer
- Geriatric Research, Education and Clinical Center, Department of Veterans Affairs Medical Center, Gainesville, FL 32608, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|