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He J, Liu R, Zheng W, Guo H, Yang Y, Zhao R, Yao W. High ambient temperature exposure during late gestation disrupts glycolipid metabolism and hepatic mitochondrial function tightly related to gut microbial dysbiosis in pregnant mice. Microb Biotechnol 2021; 14:2116-2129. [PMID: 34272826 PMCID: PMC8449678 DOI: 10.1111/1751-7915.13893] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/03/2021] [Indexed: 12/11/2022] Open
Abstract
As global warming intensifies, emerging evidence has demonstrated high ambient temperature during pregnancy negatively affects maternal physiology with compromised pregnant outcomes; however, little is known about the roles of gut microbiota and its underlying mechanisms in this process. Here, for the first time, we explored the potential mechanisms of gut microbiota involved in the disrupted glycolipid metabolism via hepatic mitochondrial function. Our results indicate heat stress (HS) reduces fat and protein contents and serum levels of insulin and triglyceride (TG), while increases that of non-esterified fatty acid (NEFA), β-hydroxybutyric acid (B-HBA), creatinine and blood urea nitrogen (BUN) (P < 0.05). Additionally, HS downregulates both mitochondrial genes (mtDNA) and nuclear encoding mitochondrial functional genes with increasing serum levels of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) (P < 0.05). Regarding microbial response, HS boosts serum levels of lipopolysaccharide (LPS) (P < 0.05) and alters β-diversity (ANOSIM, P < 0.01), increasing the proportions of Escherichia-Shigella, Acinetobacter and Klebsiella (q < 0.05), while reducing that of Ruminiclostridium, Blautia, Lachnospiraceae_NK4A136_group, Clostridium VadinBB60 and Muribaculaceae (q < 0.05). PICRUSt analysis predicts that HS upregulates 11 KEGG pathways, mainly including bile secretion and bacterial invasion of epithelial cells. The collective results suggest that microbial dysbiosis due to late gestational HS has strong associations with damaged hepatic mitochondrial function and disrupted metabolic profiles.
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Affiliation(s)
- Jianwen He
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.,Affiliated Hospital of Shaanxi University of Chinese Medicine, Shaanxi University of Chinese Medicine, Xianyang, 712000, China
| | - Riliang Liu
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Weijiang Zheng
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Huiduo Guo
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yunnan Yang
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ruqian Zhao
- Key Lab of Animal Physiology and Biochemistry, Nanjing Agricultural University, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210095, China
| | - Wen Yao
- College of Animal Science and Technology, Nanjing Agricultural University, Nanjing, 210095, China.,Key Lab of Animal Physiology and Biochemistry, Nanjing Agricultural University, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Nanjing, 210095, China
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Metformin effectively restores the HPA axis function in diet-induced obese rats. Int J Obes (Lond) 2020; 45:383-395. [PMID: 32951009 PMCID: PMC7855162 DOI: 10.1038/s41366-020-00688-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 08/21/2020] [Accepted: 09/09/2020] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The hypothalamo-pituitary-adrenal (HPA) axis is perturbed in obesity. We previously reported presence of leptin resistance in the brainstem and uncoupling between central noradrenergic tone and the HPA axis in obesity-prone (DIO) rats. Metformin is shown to lower body weight and adiposity, but the underlying mechanism is unclear. We hypothesized that this is associated with restored HPA axis function. METHODS Adult male DIO rats were placed on either a regular chow or HF diet for 7 weeks. Starting week 4, the animals were given either a low dose (60 mg/kg) or high dose (300 mg/kg) of metformin in drinking water. In addition to body weight and feeding, we examined different arms of the HPA axis to test if metformin can reinstate its function and coupling. To understand potential mechanisms, leptin signaling in the brainstem and circulating free fatty acid levels were also assessed. RESULTS Metformin treatment lowered weight gain, fat mass, caloric intake, and serum leptin levels. HPA axis activity as determined by corticotropin-releasing hormone in the median eminence and serum corticosterone was decreased by metformin in a dose-dependent manner, and so was norepinephrine (NE) in the paraventricular nucleus. Importantly, metformin completely normalized the NE-HPA axis uncoupling. While brainstem pSTAT-3 and SOCS-3, key markers of leptin signaling, were not different between groups, circulating saturated and unsaturated free fatty acids were reduced in HF-fed, metformin-treated animals. CONCLUSIONS These findings suggest that oral metformin can successfully correct HPA axis dysfunction that is associated with lowered circulating free fatty acids in DIO rats, thereby uncovering a novel effect of metformin in the treatment of obesity.
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Awawdeh MS, Dager HK, Obeidat BS. Dietary inclusion of alternative feedstuffs had no negative effects on hematological and biochemical parameters of growing Awassi lambs. Trop Anim Health Prod 2020; 52:2157-2162. [PMID: 32103384 DOI: 10.1007/s11250-020-02236-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 02/13/2020] [Indexed: 11/25/2022]
Abstract
Dietary inclusion of alternative feedstuffs (AF) could impact animal performance, ruminal ecosystem, and/or blood parameters. The objective of the current trial was to evaluate the effects of dietary inclusion of mixed AF on hematological and biochemical parameters of growing lambs. Male Awassi lambs (n = 27, average BW = 20.0 ± 0.5 kg and average age of 90 days) were randomly assigned to one of three dietary groups (9 lambs/group). Diets were formulated to contain (on DM basis) 0 (CTL; conventional diet without AF), 25% (25AF), or 50% (50AF) of mixed AF (dry bread, carob pods, olive cake, and sesame meal). Blood samples were collected from each lamb before morning feeding at the beginning (7 days after the start), middle (day 35), and end (68 day) of the study. Hematological parameters were not affected (P ≥ 0.11) by treatment diets. Except for urea N and cortisol, dietary treatments had no significant (P ≥ 0.07) effects on serum levels of all of the measured metabolites and enzymes. Lambs fed the 50AF diet had the lowest blood level of urea N and cortisol. The current study demonstrates that dietary inclusion of AF up to 50% did not negatively impact lambs' health assessed with changes in hematological and biochemical parameters.
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Affiliation(s)
- Mofleh S Awawdeh
- Department of Veterinary Pathology and Public Health, Faculty of Veterinary Medicine, Jordan University of Science and Technology, 22110, Irbid, Jordan.
| | - Hamzeh K Dager
- Department of Animal Production, Faculty of Agriculture, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Belal S Obeidat
- Department of Animal Production, Faculty of Agriculture, Jordan University of Science and Technology, Irbid, 22110, Jordan
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Responsiveness of hypothalamo-pituitary-adrenal axis to leptin is impaired in diet-induced obese rats. Nutr Diabetes 2019; 9:10. [PMID: 30886140 PMCID: PMC6423225 DOI: 10.1038/s41387-019-0076-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 10/25/2018] [Accepted: 11/06/2018] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND/OBJECTIVES Diet-induced obese (DIO) rats have altered stress (HPA) axis activity compared to diet-resistant (DR) rats when chronically exposed to a high-fat (HF) diet. Since stress axis is tightly regulated by leptin, an adipocyte-secreted hormone that is important for controlling body weight, we hypothesized that leptin action is impaired in DIO rats leading to alterations in HPA axis activity. SUBJECTS/METHODS We intraperitoneally injected selectively bred DIO and DR rats with either saline or recombinant rat leptin. HPA axis activity was assessed by measuring norepinephrine (NE) in the paraventricular nucleus (PVN), corticotropin-releasing hormone (CRH) in the median eminence, and serum corticosterone (CORT). To test if HF exposure duration and the corresponding increase in leptin differentially affects HPA axis activity, we placed animals on a chow or HF diet for 1 or 6 weeks. RESULTS Leptin injection significantly increased serum leptin levels in both DIO and DR animals. It also reduced PVN NE in both groups, indicating that noradrenergic neurons in both groups remain responsive to leptin. HF diet duration-dependently increased serum leptin only in DIO animals whereas PVN NE increased in both groups. While DR rats responded to HF diet by increasing CRH and CORT at both time-points, responses in DIO rats varied, suggesting that they have altered HPA axis activity that may be dependent on HF-induced leptin levels and/or signaling. To understand the underlying mechanisms, we measured pSTAT-3, a marker of leptin signaling, in brainstem noradrenergic neurons and found reduced pSTAT-3 in A1 region of HF-fed DIO rats. We also found higher serum free fatty acids (FFAs) and a pro-inflammatory cytokine, IL-1β. CONCLUSIONS Collectively, these findings reveal that DIO rats have inherent neuroendocrine impairment in NE-HPA axis circuitry that worsens with the extent of HF diet exposure, possibly due to brainstem leptin resistance and/or elevated circulating FFAs and IL-1β.
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Abstract
PUFA modulate hypothalamic-pituitary-adrenal (HPA) axis activity and cortisol concentrations and therefore affect physiological stress responses and the regulation of energy balance in the short- and long-term. Especially dietary intake of n-3 PUFA and a lowered n-6:n-3 ratio are highly encouraged due to beneficial and diminishing effects on basal cortisol secretions. However, the time of such effects to occur and how plasma PUFA patterns affect cortisol concentrations in the short-term was rarely investigated. In order to address this, we supplemented forty male and forty female guinea pigs with diets high in the essential PUFA α-linolenic acid (ALA, 18 : 3n-3) and linoleic acid (LA, 18 : 2n-6) for 20 d. Saliva cortisol concentrations in relation to altering plasma PUFA patterns during this time span were analysed in a repeated measurement design both during basal conditions (individual housing) in 5-d intervals and during stressful social confrontations. We detected very fast plasma PUFA accumulation rates, corresponding to the major dietary PUFA, which resulted in plasma PUFA plateau phases after 10 d. ALA negatively and LA positively affected saliva cortisol concentrations throughout the study. A positive effect of the plasma n-6:n-3 ratio on saliva cortisol concentrations was detected during peak plasma PUFA accumulations and social confrontations, while no effects were detected in relation to plasma PUFA plateau phases. These results suggest that the plasma n-6:n-3 ratio diminishes HPA axis activity during altered physiological conditions only and highlights the importance of altering plasma PUFA patterns for HPA axis functions and the control of energy balance and physiological stress.
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Nemeth M, Wallner B, Siutz C, Pschernig E, Wagner KH, Millesi E. Steroid hormone concentrations and body mass are differently affected by polyunsaturated fatty acids during the oestrous cycle in guinea pigs. Reprod Fertil Dev 2018; 30:1077-1086. [PMID: 29306361 DOI: 10.1071/rd17242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/04/2017] [Indexed: 11/23/2022] Open
Abstract
Reproductive functions in female mammals can be significantly affected by the actions of dietary polyunsaturated fatty acids (PUFAs) on steroid hormone secretion rates. Nevertheless, the effects of plasma free PUFAs on the oestrous cycle have seldom been considered. Therefore, in the present study, the diet of domestic guinea pigs was supplemented with high concentrations of different PUFAs and the effects of altered plasma PUFA patterns on steroid hormone concentrations, measured non-invasively, and body mass during oestrus and dioestrus were analysed. The oestrous cycle was characterised by increased oestrogen and cortisol concentrations in oestrus, corroborated by lowest bodyweight, whereas progesterone concentrations were highest in dioestrus. Plasma concentrations of the long-chain PUFAs docosahexaenoic acid (DHA; 22:6 ω3) and arachidonic acid (AA; 20:5 ω6) affected steroid hormone concentrations differently in oestrus and dioestrus. DHA positively affected oestrogen and progesterone concentrations and diminished cortisol concentrations only in oestrus. In contrast, AA negatively affected oestrogen and stimulated cortisol concentrations in oestrus and reduced progesterone concentrations in general. These findings imply selective and opposite contributions of DHA and AA to ovarian functions during different stages of the oestrous cycle, indicating a high biological relevance of plasma free PUFAs in female reproductive function.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Carina Siutz
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Elisabeth Pschernig
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Sciences, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Faculty of Life Sciences, Althanstrasse 14, 1090 Vienna, Austria
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Briski KP, Alenazi FSH, Shakya M, Sylvester PW. Hindbrain A2 noradrenergic neuron adenosine 5'-monophosphate-activated protein kinase activation, upstream kinase/phosphorylase protein expression, and receptivity to hormone and fuel reporters of short-term food deprivation are regulated by estradiol. J Neurosci Res 2016; 95:1427-1437. [PMID: 27618227 DOI: 10.1002/jnr.23892] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 06/28/2016] [Accepted: 07/29/2016] [Indexed: 11/10/2022]
Abstract
Estradiol (E) mitigates acute and postacute adverse effects of 12 hr-food deprivation (FD) on energy balance. Hindbrain 5'-monophosphate-activated protein kinase (AMPK) regulates hyperphagic and hypothalamic metabolic neuropeptide and norepinephrine responses to FD in an E-dependent manner. Energy-state information from AMPK-expressing hindbrain A2 noradrenergic neurons shapes neural responses to metabolic imbalance. Here we investigate the hypothesis that FD causes divergent changes in A2 AMPK activity in E- vs. oil (O)-implanted ovariectomized female rats, alongside dissimilar adjustments in circulating metabolic fuel (glucose, free fatty acids [FFA]) and energy deficit-sensitive hormone (corticosterone, glucagon, leptin) levels. FD decreased blood glucose in oil (O)- but not E-implanted ovariectomized female rats and elevated and reduced glucagon levels in O and E, respectively. FD decreased circulating leptin in O and E, but increased corticosterone and FFA concentrations in E only. Western blot analysis of laser-microdissected A2 neurons showed that glucocorticoid receptor type II and very-long-chain acyl-CoA synthetase 3 protein profiles were amplified in FD/E vs. FD/O. A2 total AMPK protein was elevated without change in activity in FD/O, whereas FD/E exhibited increased AMPK activation along with decreased upstream phosphatase expression. The catecholamine biosynthetic enzyme dopamine-β-hydroxylase (DβH) was increased in FD/O but not FD/E A2 cells. The data show discordance between A2 AMPK activation and glycemic responses to FD; sensor activity was refractory to glucose decrements in FD/O but augmented in FD/E despite stabilized glucose and elevated FFA levels. E-dependent amplification of AMPK activity may reflect adaptive conversion to fatty acid oxidation and/or glucocorticoid stimulation. FD augmentation of A2 DβH protein profiles in FD/O but not FD/E animals suggests that FD may correspondingly regulate NE synthesis vs. metabolism/release in the absence vs. presence of E. Mechanisms underlying translation of E-contingent A2 neuron responses to FD into regulatory signaling remain to be determined. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Karen P Briski
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana
| | - Fahaad S H Alenazi
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana
| | - Manita Shakya
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana
| | - Paul W Sylvester
- Department of Basic Pharmaceutical Sciences, School of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana
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Zhao L, Zhao A, Chen T, Chen W, Liu J, Wei R, Su J, Tang X, Liu K, Zhang R, Xie G, Panee J, Qiu M, Jia W. Global and Targeted Metabolomics Evidence of the Protective Effect of Chinese Patent Medicine Jinkui Shenqi Pill on Adrenal Insufficiency after Acute Glucocorticoid Withdrawal in Rats. J Proteome Res 2016; 15:2327-36. [PMID: 27267777 DOI: 10.1021/acs.jproteome.6b00409] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Glucocorticoids are commonly used in anti-inflammatory and immunomodulatory therapies, but glucocorticoid withdrawal can result in life-threatening risk of adrenal insufficiency. Chinese patented pharmaceutical product Jinkui Shenqi pill (JKSQ) has potent efficacy on clinical adrenal insufficiency resulting from glucocorticoid withdrawal. However, the underlying molecular mechanism remains unclear. We used an animal model to study JKSQ-induced metabolic changes under adrenal insufficiency and healthy conditions. Sprague-Dawley rats were treated with hydrocortisone for 7 days with or without 15 days of JKSQ pretreatment. Sera were collected after 72 h hydrocortisone withdrawal and used for global and free fatty acids (FFAs)-targeted metabolomics analyses using gas chromatography/time-of-flight mass spectrometry and ultraperformance liquid chromatography/quadruple time-of-flight mass spectrometry. Rats without hydrocortisone treatment were used as controls. JKSQ pretreatment normalized the significant changes of 13 serum metabolites in hydrocortisone-withdrawal rats, involving carbohydrates, lipids, and amino acids. The most prominent effect of JKSQ was on the changes of FFAs and some [product FFA]/[precursor FFA] ratios, which represent estimated desaturase and elongase activities. The opposite metabolic responses of JKSQ in adrenal insufficiency rats and normal rats highlighted the "Bian Zheng Lun Zhi" (treatment based on ZHENG differentiation) guideline of TCM and suggested that altered fatty acid metabolism was associated with adrenal insufficiency after glucocorticoid withdrawal and the protective effects of JKSQ.
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Affiliation(s)
- Linjing Zhao
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science , Shanghai 201620, China.,Metabolomics Shared Resource, University of Hawaii Cancer Center , Honolulu, Hawaii 96813, United States
| | - Aihua Zhao
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai 200233, China
| | - Tianlu Chen
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai 200233, China
| | - Wenlian Chen
- Metabolomics Shared Resource, University of Hawaii Cancer Center , Honolulu, Hawaii 96813, United States
| | - Jiajian Liu
- Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai 200233, China
| | - Runmin Wei
- Metabolomics Shared Resource, University of Hawaii Cancer Center , Honolulu, Hawaii 96813, United States
| | - Jing Su
- School of Pharmacy, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Xuelan Tang
- School of Pharmacy, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Keyi Liu
- School of Pharmacy, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Ran Zhang
- School of Pharmacy, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Guoxiang Xie
- Metabolomics Shared Resource, University of Hawaii Cancer Center , Honolulu, Hawaii 96813, United States
| | - Jun Panee
- Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii at Manoa , Manoa, Hawaii 96813, United States
| | - Mingfeng Qiu
- School of Pharmacy, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Wei Jia
- Metabolomics Shared Resource, University of Hawaii Cancer Center , Honolulu, Hawaii 96813, United States.,Shanghai Key Laboratory of Diabetes Mellitus and Center for Translational Medicine, Shanghai Jiao Tong University Affiliated Sixth People's Hospital , Shanghai 200233, China
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Davidson J, Higgs W, Rotondo D. Eicosapentaenoic acid suppression of systemic inflammatory responses and inverse up-regulation of 15-deoxyΔ(12,14) prostaglandin J2 production. Br J Pharmacol 2015; 169:1130-9. [PMID: 23586396 DOI: 10.1111/bph.12209] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 03/05/2013] [Accepted: 03/22/2013] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE Eicosapentaenoic acid (EPA) has been shown to suppress immune cell responses, such as cytokine production and downstream PG production in vitro. Studies in vivo, however, have used EPA as a minor constituent of fish oil with variable results. We investigated the effects of EPA on systemic inflammatory responses as pure EPA has not been evaluated on immune/inflammatory responses in vivo. EXPERIMENTAL APPROACH Rabbits were administered polyinosinic: polycytidylic acid (poly I:C) i.v. before and after oral treatment with EPA for 42 days (given daily). The responses to IL-1β and TNF-α were also studied. Immediately following administration of poly I:C, body temperature was continuously monitored and blood samples were taken. Plasma levels of IL-1β, PGE2 (PGE2), and 15-deoxy-Δ(12,14)-PGJ2 (15d-PGJ2) were measured by enzyme immunoassay. KEY RESULTS Following EPA treatment, the fever response to poly I:C was markedly suppressed compared with pretreatment responses. This was accompanied by a parallel reduction in the poly I:C-stimulated elevation in plasma levels of IL-1β and PGE2. Paradoxically, the levels of 15d-PGJ2 were higher following EPA treatment. EPA treatment did not significantly alter the fever response or plasma levels of PGE2 in response to either IL-1β or TNF-α. CONCLUSION AND IMPLICATIONS Oral treatment with EPA can suppress immune/inflammatory responses in vivo via a suppression of upstream cytokine production resulting in a decreased fever response and indirectly reducing circulating levels of PGE2. EPA also enhances the production of the cytoprotective prostanoid 15d-PGJ2 indicating the therapeutic benefit of EPA.
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Affiliation(s)
- Jillian Davidson
- Strathclyde Institute of Pharmacy & Biomedical Sciences, University of Strathclyde, Glasgow, UK
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10
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Nemeth M, Millesi E, Wagner KH, Wallner B. Effects of diets high in unsaturated Fatty acids on socially induced stress responses in Guinea pigs. PLoS One 2014; 9:e116292. [PMID: 25551380 PMCID: PMC4281161 DOI: 10.1371/journal.pone.0116292] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2014] [Accepted: 12/06/2014] [Indexed: 02/01/2023] Open
Abstract
Unsaturated fatty acids (UFAs), such as omega-3 and omega-6 poly- and omega-9 monounsaturated fatty acids are important nutrients and major components of neuronal cell membranes. They play a major role in modulating brain functions and physiology and may therefore diminish behavioral and physiological stress reactions in corroboration with decreased cortisol concentrations. Functionally, cortisol itself can modulate several behaviors and also the fatty acid metabolism in the long term. But only little is known about the behavioral and physiological influences of dietary UFAs in a social group, where individuals are regularly exposed to stressful situations. Therefore, the aim of this study was to determine the effects of dietary UFAs on saliva cortisol concentrations and behavioral responses in socially confronted guinea pigs. Three groups of animals were additionally supplemented with 500 mg chia seeds (high in omega-3), walnuts (high in omega-6), or peanuts (high in omega-9) per kg bodyweight each day and compared to a control group. During social confrontation saliva cortisol concentrations significantly increased in all groups, which was accompanied by a loss in bodyweight. However, cortisol levels remained lower in the chia and walnut groups compared to controls. Additionally, the walnut group displayed significantly increased locomotion, while no differences between groups were detected in socio-positive, sexual, or aggressive behaviors. Total plasma omega-3, omega-6, and omega-9 fatty acids were significantly increased in the corresponding groups, due to the dietary supplementations. However, a significant decrease in plasma omega-3 and an increase in plasma n-6 fatty acids were detected in the chia group when comparing the measurements before and after social confrontation. We conclude that both omega-3 and omega-6 polyunsaturated fatty acids can diminish behavioral and physiological stress responses to the social environment, enabling individuals to cope with social stressors, but at the expense of plasma derived omega-3 fatty acids.
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Affiliation(s)
- Matthias Nemeth
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
| | - Eva Millesi
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
| | - Karl-Heinz Wagner
- Department of Nutritional Science, University of Vienna, Vienna, Austria
| | - Bernard Wallner
- Department of Behavioural Biology, University of Vienna, Vienna, Austria
- Cognitive Science Research Platform, University of Vienna, Vienna, Austria
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11
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Burdick Sanchez NC, Carroll JA, Donaldson JR, Buntyn JO, Schmidt TB. Exogenous administration of lipids to steers alters aspects of the innate immune response to endotoxin challenge. Innate Immun 2014; 21:512-22. [DOI: 10.1177/1753425914552741] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/03/2014] [Indexed: 11/16/2022] Open
Abstract
This study examined the effects of increasing energy availability from both dextrose and lipid treatments on the pro-inflammatory response to LPS in Holstein steers. Steers were randomly assigned to one of three groups: saline at 0.5 ml/kg body weight (Control) or 50% dextrose [0.5 ml/kg body weight (Dextrose) to mimic calm cattle’s response to LPS] administered immediately prior to LPS (0.5 µg/kg body weight at 0 h) or continuous lipid emulsion infusion from −1 to 6 h [Intralipid 20% (Baxter, Deerfield, IL USA); 0.5 ml/kg/hr (Lipid) to mimic temperamental cattle]. Concentrations of non-esterified fatty acids (NEFA) were greater in Lipid compared with Control and Dextrose steers. A greater decrease in the change in rectal temperature, relative to baseline, was observed in response to LPS in Dextrose in comparison to control and Lipid steers. Cortisol was greater in Lipid than Dextrose and Control steers from −0.5 to 0 h, yet decreased from 0.5 to 5.5 h relative to LPS challenge. Concentrations of IL-6 were decreased in Lipid steers compared with Dextrose and Control steers, and were decreased in Dextrose compared with Control steers post-LPS challenge. These data suggest that increasing circulating NEFA using an exogenous Lipid emulsion may modulate the pro-inflammatory response in steers.
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Affiliation(s)
| | | | - Janet R Donaldson
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS, USA
| | - Joe O Buntyn
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Ty B Schmidt
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, USA
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12
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Abstract
Significant interactions exist between fatty acids and the endocrine system. Dietary fatty acids alter both hormone and neuropeptide concentrations and also their receptors. In addition, hormones affect the metabolism of fatty acids and the fatty acid composition of tissue lipids. The principal hormones involved in lipid metabolism are insulin, glucagon, catecholamines, cortisol and growth hormone. The concentrations of these hormones are altered in chronic degenerative conditions such as diabetes and cardiovascular disease, which in turn leads to alterations in tissue lipids. Lipogenesis and lipolysis, which modulate fatty acid concentrations in plasma and tissues, are under hormonal control. Neuropeptides are also involved in lipid metabolism in brain and other tissues. Polyunsaturated fatty acids are also precursors for eicosanoids including prostaglandins, leucotrienes, and thromboxanes, which have hormone-like activities. Fatty acids in turn affect the endocrine system. Saturated and trans fatty acids decrease insulin concentration leading to insulin resistance. In contrast, polyunsaturated fatty acids increase plasma insulin concentration and decrease insulin resistance. In humans, omega3 polyunsaturated fatty acids alter the levels of opioid peptides in plasma. Free fatty acids have been reported to inhibit glucagon release. Fatty acids also affect receptors for hormones and neuropeptides.
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Affiliation(s)
- Sam J Bhathena
- Phytonutrients Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, USDA, Beltsville, MD, 20705-2350, USA.
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13
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Garrel G, Simon V, Denoyelle C, Cruciani-Guglielmacci C, Migrenne S, Counis R, Magnan C, Cohen-Tannoudji J. Unsaturated fatty acids stimulate LH secretion via novel PKCepsilon and -theta in gonadotrope cells and inhibit GnRH-induced LH release. Endocrinology 2011; 152:3905-16. [PMID: 21862612 DOI: 10.1210/en.2011-1167] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The activity of pituitary gonadotrope cells, crucial for reproductive function, is regulated by numerous factors including signals related to nutritional status. In this work, we demonstrated, for the first time, that in vivo central exposure of rats to lipids intracarotid infusion of a heparinized triglyceride emulsion selectively increases the expression of pituitary LH subunit genes without any alteration of pituitary GnRH receptor and hypothalamic GnRH or Kiss-1 transcript levels. Furthermore, we showed that unsaturated fatty acids (UFA), oleate and linoleate, increase LH release in a dose-dependent manner as well as LHβ mRNA levels in both immortalized LβT2 gonadotrope cell line and rat primary cell cultures. In contrast, the saturated palmitate was ineffective. ACTH or TSH secretion was unaffected by UFA treatment. We demonstrated in LβT2 cells that linoleate effect is mediated neither by activation of membrane fatty acid (FA) receptors GPR40 or GPR120 although we characterized these receptors in LβT2 cells, nor through nuclear peroxisome proliferator-activated receptors. Furthermore, linoleate β-oxidation is not required for its action on LH secretion. In contrast, pharmacological inhibition of protein kinase C (PKC) or ERK pathways significantly prevented linoleate-stimulated LH release. Accordingly, linoleate was shown to activate novel PKC isoforms, PKCε and -θ, as well as ERK1/2 in LβT2 cells. Lastly, unsaturated, but not saturated, FA inhibited GnRH-induced LH secretion in LβT2 cells as well as in pituitary cell cultures. Altogether, these results suggest that the pituitary is a relevant site of FA action and that UFA may influence reproduction by directly interfering with basal and GnRH-dependent gonadotrope activity.
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Affiliation(s)
- Ghislaine Garrel
- Université Paris Diderot, Sorbonne Paris Cité, Biologie Fonctionnelle et Adaptative, Equipe d'accueil conventionnée, Centre National de la Recherche Scientifique 4413, 75205 Paris Cedex 13, France
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Man TY, Michailidou Z, Gokcel A, Ramage L, Chapman KE, Kenyon CJ, Seckl JR, Morton NM. Dietary manipulation reveals an unexpected inverse relationship between fat mass and adipose 11β-hydroxysteroid dehydrogenase type 1. Am J Physiol Endocrinol Metab 2011; 300:E1076-84. [PMID: 21406612 PMCID: PMC3605916 DOI: 10.1152/ajpendo.00531.2010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Increased dietary fat intake is associated with obesity, insulin resistance, and metabolic disease. In transgenic mice, adipose tissue-specific overexpression of the glucocorticoid-amplifying enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) exacerbates high-fat (HF) diet-induced visceral obesity and diabetes, whereas 11β-HSD1 gene knockout ameliorates this, favoring accumulation of fat in nonvisceral depots. Paradoxically, in normal mice HF diet-induced obesity (DIO) is associated with marked downregulation of adipose tissue 11β-HSD1 levels. To identify the specific dietary fats that regulate adipose 11β-HSD1 and thereby impact upon metabolic disease, we either fed mice diets enriched (45% calories as fat) in saturated (stearate), monounsaturated (oleate), or polyunsaturated (safflower oil) fats ad libitum or we pair fed them a low-fat (11%) control diet for 4 wk. Adipose and liver mass and glucocorticoid receptor and 11β-HSD1 mRNA and activity levels were determined. Stearate caused weight loss and hypoinsulinemia, partly due to malabsorption, and this markedly increased plasma corticosterone levels and adipose 11β-HSD1 activity. Oleate induced pronounced weight gain and hyperinsulinemia in association with markedly low plasma corticosterone and adipose 11β-HSD1 activity. Weight gain and hyperinsulinemia was less pronounced with safflower compared with oleate despite comparable suppression of plasma corticosterone and adipose 11β-HSD1. However, with pair feeding, safflower caused a selective reduction in visceral fat mass and relative insulin sensitization without affecting plasma corticosterone or adipose 11β-HSD1. The dynamic depot-selective relationship between adipose 11β-HSD1 and fat mass strongly implicates a dominant physiological role for local tissue glucocorticoid reactivation in fat mobilization.
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Affiliation(s)
- Tak Yung Man
- Endocrinology Unit, Centre for Cardiovascular Sciences, Queens Medical Research Institute, University of Edinburgh, Edinburgh, United Kingdom
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15
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Walker CD. Maternal touch and feed as critical regulators of behavioral and stress responses in the offspring. Dev Psychobiol 2010; 52:638-50. [DOI: 10.1002/dev.20492] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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16
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Kuo YT, So PW, Parkinson JR, Yu WS, Hankir M, Herlihy AH, Goldstone AP, Frost GS, Wasserfall C, Bell JD. The combined effects on neuronal activation and blood–brain barrier permeability of time and n-3 polyunsaturated fatty acids in mice, as measured in vivo using MEMRI. Neuroimage 2010; 50:1384-91. [DOI: 10.1016/j.neuroimage.2010.01.057] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 01/06/2010] [Accepted: 01/14/2010] [Indexed: 11/24/2022] Open
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17
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The effect of fasting on the diurnal rhythm of rat ACHT and corticosterone secretion. ARCH BIOL SCI 2008. [DOI: 10.2298/abs0804541d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
A tight association of feeding, metabolism, and function of the hypothalamo-pituitary-adrenocortical (HPA) axis is well known. Studies of HPA axis responsivity to various diets and food restriction show that not only fasting but also the cyclic circadian input importantly determine these responses. We therefore studied the response of the rat HPA system to different fasting periods (12, 18, 24, 36, and 48 h), all imposed at 6 PM, by measuring blood ACTH and corticosterone concentration. The corresponding metabolic parameters, e.g., blood glucose and free fatty acid (FFA) levels, were also assessed. The obtained results show that fasting altered the normal diurnal rhythm in levels of blood ACTH and FFA, but not corticosterone and glucose. All applied fasting periods increased HPA system activity in comparison with ad libitum fed rats. However, the most pronounced elevation in the blood ACTH concentration was observed after 18 h and 36 h of fasting, while the CORT increment was the highest 48 h after food restriction began. As expected, the blood glucose concentration decreased under the influence of all fasting periods, being the lowest after 12 h of overnight fasting. In contrast to that, fasted rats exhibited a normal level of serum FFA early in the morning, an elevated level there?after, and the peak level 48 h after the onset of starvation.
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18
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Pecoraro N, Ginsberg AB, Warne JP, Gomez F, la Fleur SE, Dallman MF. Diverse basal and stress-related phenotypes of Sprague Dawley rats from three vendors. Physiol Behav 2006; 89:598-610. [PMID: 16935312 DOI: 10.1016/j.physbeh.2006.07.019] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Revised: 07/18/2006] [Accepted: 07/19/2006] [Indexed: 10/24/2022]
Abstract
Based on observed phenotypic differences in growth and ACTH responses to stress in Sprague Dawley rats obtained from different vendors, we ran head-to-head comparisons on rats obtained from three different vendors, Harlan, Charles River, and Simonsen, with respect to baseline phenotypic differences and a metabolic feedback hypothesis of hypothalamo-pituitary-adrenal (HPA) regulation. Charles River and Harlan rats gained weight faster than Simonsen rats, but chow intake standardized for body weight was not increased, consistent with their greater caloric efficiency. Weight gain was inversely related with mean daily temperatures, without differences in activity levels. Half of the animals given lard and 32% sucrose solutions in addition to chow increased caloric intake and core temperature, decreased caloric efficiency, and increased fat depots, leptin, and in Simonsen rats, insulin. A 5-day regimen of once-daily 2-h restraint decreased feeding and caloric efficiency. Rats from two vendors with the availability of sucrose and lard, Charles River and Simonsen, showed blunted HPA responses to restraint compared to chow controls, whereas the Harlans exhibited no adrenocorticotropin (ACTH) response and an amplified adrenocortical response on the high-energy diet compared to chow controls. Substantial phenotypic differences exist between Sprague Dawley rats from different vendors with respect to metabolism and HPA function. The metabolic feedback hypothesis was supported in two of the three vendors' rats.
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Affiliation(s)
- Norman Pecoraro
- Department of Physiology, School of Medicine, University of California San Francisco, 94143-0444, United States.
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19
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Mai K, Bobbert T, Kullmann V, Andres J, Bähr V, Maser-Gluth C, Rochlitz H, Spranger J, Diederich S, Pfeiffer AFH. No effect of free fatty acids on adrenocorticotropin and cortisol secretion in healthy young men. Metabolism 2006; 55:1022-8. [PMID: 16839836 DOI: 10.1016/j.metabol.2006.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2005] [Accepted: 03/02/2006] [Indexed: 01/01/2023]
Abstract
Free fatty acids (FFAs) affect anterior pituitary function. However, the effect of FFAs on corticotropin (ACTH) and cortisol in humans is controversial. Thus, we assessed the effect of a pronounced increase in circulating FFA levels induced by infusion of lipid/heparin on ACTH and cortisol secretion in young men. Eight healthy male volunteers who underwent a 10-hour overnight fast were investigated. A 20% lipid/heparin or saline/heparin infusion was given at a rate of 1.5 mL/min for 6 hours. A euglycemic hyperinsulinemic clamp was performed in 6 subjects 4 hours after the start of infusion. To assess steroid metabolism, we measured ACTH, cortisol, FFAs, and urinary steroids. Lipid infusion increased FFAs (6.06 +/- 0.52 vs 0.70 +/- 0.23 mmol/L; P < .005) and induced insulin resistance (glucose infusion rate, 4.08 +/- 2.15 vs 6.02 +/- 2.60 mg/kg per minute; P < .005). Serum cortisol and plasma ACTH decreased independent of lipid/heparin or saline/heparin infusion. In addition, we found no effect of hyperinsulinemia on ACTH and cortisol levels. There were no differences in urinary free cortisol, urinary free cortisone, 5beta-tetrahydrocortisol, 5alpha-tetrahydrocortisol, and tetrahydrocortisone. In conclusion, FFAs had no effect on basal ACTH and cortisol secretion in normal-weight young men. In addition, no alterations in urinary glucocorticoid metabolites were detected, suggesting unchanged cortisol metabolism during lipid infusion.
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Affiliation(s)
- Knut Mai
- Department of Endocrinology, Diabetes and Nutrition, Charite-University Medicine Berlin, Campus Benjamin Franklin, 12200 Berlin, Germany.
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20
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Walker CD. Nutritional aspects modulating brain development and the responses to stress in early neonatal life. Prog Neuropsychopharmacol Biol Psychiatry 2005; 29:1249-63. [PMID: 16253410 DOI: 10.1016/j.pnpbp.2005.08.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/26/2005] [Indexed: 10/25/2022]
Abstract
Nutrition is one of the critical factors insuring adequate growth and development in all species. In particular, brain development is sensitive to specific nutrient intake such as proteins and lipids, which are important for cell membrane formation and myelinization. Carbohydrate intake insures adequate short-term energy supply, but has important effects on the activity of the hypothalamic-pituitary-adrenal (HPA) axis to regulate stress responsiveness. This review focuses on the effects of carbohydrates and fat on the activity of the HPA axis as well as other brain-related functions such as pain modulation, neuropeptide and neurotransmitters release, and some aspects related to cognitive functions. The role of leptin, DHA and AA as mediators of the effects of fat on the brain is discussed.
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Affiliation(s)
- Claire-Dominique Walker
- Douglas Hospital Research Center, Department of Psychiatry, McGill University, Montreal, 6875 Lasalle Blvd, Verdun, QC, Canada H4H 1R3.
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21
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la Fleur SE, Houshyar H, Roy M, Dallman MF. Choice of lard, but not total lard calories, damps adrenocorticotropin responses to restraint. Endocrinology 2005; 146:2193-9. [PMID: 15705773 DOI: 10.1210/en.2004-1603] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although rats given the choice of eating high-density calories as concentrated sucrose solutions or lard exhibit reduced responsivity in the hypothalamo-pituitary-adrenal axis, rats fed high-fat diets have normal or augmented responses to stressors. To resolve this apparent discrepancy, we compared in adult male rats the effects of 7-d feeding with lard + chow (choice) to feeding a 50% lard-chow mixture (no-choice) and to chow only. Rats with choice composed diets with 50-60% total calories from lard. Rats were exposed to 30 min of restraint on d 7. In the choice group, there was a robust inhibition of ACTH and corticosterone responses to restraint compared with chow or no-choice groups. Total caloric intake was less with choice than no-choice. Fat depot weights and body weight gain were similar in the high-fat groups. Leptin concentrations were equal but insulin was higher in the choice group. We conclude the following: 1) choice of eating high-density calories strongly damps hypothalamo-pituitary-adrenal responses to stress; without choice, high-density diet is ineffective; and 2) insulin may signal metabolic well-being, and may act through hypothalamic sites to reduce caloric intake but through forebrain sites to damp stress responses.
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Affiliation(s)
- Susanne E la Fleur
- Department of Physiology, University of California San Francisco, San Francisco, California 94143-0444, USA
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22
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Kok P, Kok SW, Buijs MM, Westenberg JJM, Roelfsema F, Frölich M, Stokkel MPM, Meinders AE, Pijl H. Enhanced circadian ACTH release in obese premenopausal women: reversal by short-term acipimox treatment. Am J Physiol Endocrinol Metab 2004; 287:E848-56. [PMID: 15280154 DOI: 10.1152/ajpendo.00254.2004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Several studies suggest that the hypothalamo-pituitary-adrenal (HPA) axis is exceedingly active in obese individuals. Experimental studies show that circulating free fatty acids (FFAs) promote the secretory activity of the HPA axis and that human obesity is associated with high circulating FFAs. We hypothesized that HPA axis activity is enhanced and that lowering of circulating FFAs by acipimox would reduce spontaneous secretion of the HPA hormonal ensemble in obese humans. To evaluate these hypotheses, diurnal ACTH and cortisol secretion was studied in 11 obese and 9 lean premenopausal women (body mass index: obese 33.5 +/- 0.9 vs. lean 21.2 +/- 0.6 kg/m(2), P < 0.001) in the early follicular stage of their menstrual cycle. Obese women were randomly assigned to treatment with either acipimox (inhibitor of lipolysis, 250 mg orally four times daily) or placebo in a double-blind crossover design, starting one day before admission until the end of the blood-sampling period. Blood samples were taken during 24 h with a sampling interval of 10 min for assessment of plasma ACTH and cortisol concentrations. ACTH and cortisol secretion rates were estimated by multiparameter deconvolution analysis. Daily ACTH secretion was substantially higher in obese than in lean women (7,950 +/- 1,212 vs. 2,808 +/- 329 ng/24 h, P = 0.002), whereas cortisol was not altered (obese 36,362 +/- 5,639 vs. lean 37,187 +/- 4,239 nmol/24 h, P = 0.912). Acipimox significantly reduced ACTH secretion in the obese subjects (acipimox 5,850 +/- 769 ng/24 h, P = 0.039 vs. placebo), whereas cortisol release did not change (acipimox 33,542 +/- 3,436 nmol/24 h, P = 0.484 vs. placebo). In conclusion, spontaneous ACTH secretion is enhanced in obese premenopausal women, whereas cortisol production is normal. Reduction of circulating FFA concentrations by acipimox blunts ACTH release in obese women, which suggests that FFAs are involved in the pathophysiology of this neuroendocrine anomaly.
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Affiliation(s)
- Petra Kok
- Department of General Internal Medicine, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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23
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Lanfranco F, Gianotti L, Pivetti S, Navone F, Rossetto R, Tassone F, Gai V, Ghigo E, Maccario M. Obese patients with obstructive sleep apnoea syndrome show a peculiar alteration of the corticotroph but not of the thyrotroph and lactotroph function. Clin Endocrinol (Oxf) 2004; 60:41-8. [PMID: 14678286 DOI: 10.1111/j.1365-2265.2004.01938.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Obstructive sleep apnoea syndrome (OSAS) is strongly associated with obesity (OB) and is characterized by several changes in endocrine functions, e.g. GH/IGF-I axis, adrenal and thyroid activity. It is still unclear whether these alterations simply reflect overweight or include peculiar hypoxia-induced hormonal alterations. Hormonal evaluations have been generally performed in basal conditions but we have recently reported that OSAS is characterized by a more severe reduction of the GH releasable pool in comparison to simple obesity. We aimed to extend our evaluation of anterior pituitary function to corticotroph, thyrotroph and lactotroph secretion under dynamic testing in OSAS in comparison with simply obese and normal subjects. SUBJECTS AND METHODS In 15 male patients with OSAS [age, mean +/- SEM 43.5 +/- 1.6 years; body mass index (BMI) 39.2 +/- 3.1 kg/m2; apnoea/hypopnoea index, (AHI) 53.4 +/- 8.7], 15 male patients with simple obesity (OB, age 39.7 +/- 1.2 years; BMI 41.2 +/- 2.0 kg/m2; AHI 3.1 +/- 1.2 events/h of sleep) and in 15 normal lean male subjects (NS, age 38.2 +/- 1.4 years; BMI 21.2 +/- 0.8 kg/m2; AHI 1.9 +/- 0.8 events/h of sleep) we evaluated: (a) the ACTH and cortisol responses to CRH [2 microg/kg intravenously (i.v.)] and basal 24 h UFC levels; (b) the TSH and PRL responses to TRH (5 microg/kg iv) as well as FT3 and FT4 levels. RESULTS Twenty-four-hour UFC levels in OSAS and OB were similar and within the normal range. Basal ACTH and cortisol levels were similar in all groups. However, the ACTH response to CRH in OSAS (Deltapeak: 30.3 +/- 3.8 pmol/l; DeltaAUC: 682.8 +/- 128.4 pmol*h/l) was markedly higher (P < 0.001) than in OB (Deltapeak: 9.3 +/- 1.4 pmol/l; DeltaAUC 471.5 +/- 97.3 pmol*h/l), which, in turn, was higher (P < 0.05) than in NS (Deltapeak: 3.3 +/- 0.9 pmol/l; DeltaAUC 94.7 +/- 76.7 pmol*h/l). On the other hand, the cortisol response to CRH was not significantly different in the three groups. Basal FT3 and FT4 levels as well as the TSH response to TRH were similar in all groups. Similarly, both basal PRL levels and the PRL response to TRH were similar in the three groups. CONCLUSIONS With respect to patients with simple abdominal obesity, obese patients with OSAS show a more remarkable enhancement of the ACTH response to CRH but a preserved TSH and PRL responsiveness to TRH. These findings indicate the existence of a peculiarly exaggerated ACTH hyper-responsiveness to CRH that would reflect hypoxia- and/or sleep-induced alterations of the neural control of corticotroph function; this further alteration is coupled to the previously described, peculiar reduction of somatotroph function.
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Affiliation(s)
- F Lanfranco
- Division of Endocrinology and Metabolism, Department of Internal Medicine, University of Turin, Turin, Italy
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24
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Abstract
Most attempts at weight loss are frustrated by the body's propensity to maintain fat mass. There are genetic and environmental mechanisms behind this phenomenon, such as thrifty genes, sedentary lifestyle and abundant food resources. We will outline a physiologic mechanism that may perpetuate obesity once it develops. Specifically, we suggest that obesity-induced hyperinsulinemia facilitates fuel storage as fat. This can be exacerbated by high glucocorticoid activity, low growth hormone (GH) activity and the paradoxical increase in free fatty acid (FFA) flux resulting from basal lipolysis in an expanded fat mass. We also outline mechanisms by which obesity may perpetuate low GH and increased glucocorticoid activity in the metabolic syndrome.
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Affiliation(s)
- John P Girod
- Department of General Internal Medicine, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, Ohio 44195, USA
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25
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Tassone F, Grottoli S, Rossetto R, Maccagno B, Gauna C, Giordano R, Ghigo E, Maccario M. Glucagon administration elicits blunted GH but exaggerated ACTH response in obesity. J Endocrinol Invest 2002; 25:551-6. [PMID: 12109628 DOI: 10.1007/bf03345499] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Reduction in both spontaneous and stimulated GH secretion in obesity has been clearly demonstrated. Mild hyperactivity of hypothalamus-pituitary-adrenal (HPA) axis has been also reported. Glucagon, at least after im administration, induces clear increase in either GH or ACTH and F levels but its effect on somatotroph and corticotroph secretion in obesity has never been studied. In 7 patients with abdominal obesity (OB, aged 24-42 yr, BMI: 29.1-43.9 kg/m2, waist/hip ratio [WHR]: 0.86-1.00) we studied the GH, ACTH and F responses to the im administration of glucagon (0.017 mg/kg at 0 min). The results in OB were compared with those in a group of 6 age-matched controls normal subjects (Ns aged 26-32 yr, BMI 19.7-22.5 kg/m2). In Ns glucagon administration induced clear increase in GH (peak vs baseline, mean+/-SE: 11.6+/-3.4 vs 3.3+/-0.7 microg/l, p<0.02), and ACTH (52.9+/-15.2 vs 19.0+/-1.5 pg/ml, p<0.02) levels which peaked at +150 and +165 min, respectively. Increase in F levels (222.3+/-23.8 vs 158.3+/-7.0 ng/ml, p<0.05) was also recorded but peaked at +180 min. In OB glucagon administration induced GH response (7.4+/-2.3 vs 0.8+/-0.6 microg/l) lower (p<0.05) than that recorded in Ns; when the GH responses were evaluated by co-variance analysis, a significant difference between the 2 groups was recorded in term of peaks but not of AUCs. On the other hand, the ACTH response to glucagon in OB was higher than that in Ns (11452.6+/-2447.7 vs 4892.2+/-719.4 pg/ml x min, p<0.05). The F response to glucagon in OB and Ns was, however, similar (24057.9+/-4109.1 vs 29835.9+/-1566.0 ng/ml x min). In conclusion, this study demonstrates that in obese patients the im administration of glucagon elicits blunted GH response but exaggerated ACTH increase which is uncoupled with the adrenal response. These findings agree with the existence of concomitant GH insufficiency and altered corticotroph function in obesity.
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Affiliation(s)
- F Tassone
- Department of Internal Medicine, University of Turin, Italy
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26
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Abstract
Evolution through natural selection can be described as driven by a perpetual conflict of individuals competing for limited resources. Recently, I postulated that the shortage of resources godfathered the evolutionary achievements of the differentiation-apoptosis programming [Rev. Neurosci. 12 (2001) 217]. Unicellular deprivation-induced differentiation into germ cell-like spores can be regarded as the archaic reproduction events which were fueled by the remains of the fratricided cells of the apoptotic fruiting body. Evidence has been accumulated suggesting that conserved through the ages as the evolutionary legacy of the germ-soma conflict, the somatic loss of immortality during the ontogenetic segregation of primordial germ cells recapitulates the archaic fate of the fruiting body. In this heritage, somatic death is a germ cell-triggered event and has been established as evolutionary-fixed default state following asymmetric reproduction in a world of finite resources. Aging, on the other hand, is the stress resistance-dependent phenotype of the somatic resilience that counteracts the germ cell-inflicted death pathway. Thus, aging is a survival response and, in contrast to current beliefs, is antagonistically linked to death that is not imposed by group selection but enforced upon the soma by the selfish genes of the "enemy within". Environmental conditions shape the trade-off solutions as compromise between the conflicting germ-soma interests. Mechanistically, the neuroendocrine system, particularly those components that control energy balance, reproduction and stress responses, orchestrate these events. The reproductive phase is a self-limited process that moulds onset and progress of senescence with germ cell-dependent factors, e.g. gonadal hormones. These degenerate the regulatory pacemakers of the pineal-hypothalamic-pituitary network and its peripheral, e.g. thymic, gonadal and adrenal targets thereby eroding the trophic milieu. The ensuing cellular metabolic stress engenders adaptive adjustments of the glucose-fatty acid cycle, responses that are adequate and thus fitness-boosting under fuel shortage (e.g. during caloric restriction) but become detrimental under fuel abundance. In a Janus-faced capacity, the cellular stress response apparatus expresses both tolerogenic and mutagenic features of the social and asocial deprivation responses [Rev. Neurosci. 12 (2001) 217]. Mediated by the derangement of the energy-Ca(2+)-redox homeostatic triangle, a mosaic of dedifferentiation/apoptosis and mutagenic responses actuates the gradual exhaustion of functional reserves and eventually results in a multitude of aging-related diseases. This scenario reconciles programmed and stochastic features of aging and resolves the major inconsistencies of current theories by linking ultimate and proximate causes of aging. Reproduction, differentiation, apoptosis, stress response and metabolism are merged into a coherent regulatory network that stages aging as a naturally selected, germ cell-triggered and reproductive phase-modulated deprivation response.
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Affiliation(s)
- Kurt Heininger
- Department of Neurology, Heinrich Heine Universität, Düsseldorf, Germany.
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27
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Abstract
Significant interactions exist between fatty acids and the endocrine system. Hormones affect the metabolism of fatty acids and the fatty acid composition of tissue lipids. The principal hormones involved in lipid metabolism are insulin, glucagon, catecholamines, cortisol and growth hormone. The concentrations of these hormones are altered in chronic degenerative conditions such as diabetes and cardiovascular disease, which in turn lead to alterations in tissue lipids. Lipogenesis and lipolysis, which modulate fatty acid concentrations in plasma and tissues, are under hormonal control. Neuropeptides are involved in lipid metabolism in brain and other tissues. Polyunsaturated fatty acids (PUFA) are also precursors for eicosanoids including prostaglandins, leukotrienes, and thromboxanes, which have hormone-like activities. Fatty acids in turn alter both hormone and neuropeptide concentrations and their receptors. Saturated and trans fatty acids (TFA) decrease insulin concentration leading to insulin resistance. In contrast, PUFA increase plasma insulin concentration and decrease insulin resistance. In humans, omega-3 PUFA alter the levels of opioid peptides in plasma.
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Affiliation(s)
- S J Bhathena
- Phytonutrients Laboratory, Beltsville Human Nutrition Research Center, Agricultural Research Service, USDA, MD 20705, USA.
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28
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Abstract
Normal ageing and Alzheimer's disease (AD) have many features in common and, in many respects, both conditions only differ by quantitative criteria. A variety of genetic, medical and environmental factors modulate the ageing-related processes leading the brain into the devastation of AD. In accordance with the concept that AD is a metabolic disease, these risk factors deteriorate the homeostasis of the Ca(2+)-energy-redox triangle and disrupt the cerebral reserve capacity under metabolic stress. The major genetic risk factors (APP and presenilin mutations, Down's syndrome, apolipoprotein E4) are associated with a compromise of the homeostatic triangle. The pathophysiological processes leading to this vulnerability remain elusive at present, while mitochondrial mutations can be plausibly integrated into the metabolic scenario. The metabolic leitmotif is particularly evident with medical risk factors which are associated with an impaired cerebral perfusion, such as cerebrovascular diseases including stroke, cardiovascular diseases, hypo- and hypertension. Traumatic brain injury represents another example due to the persistent metabolic stress following the acute event. Thyroid diseases have detrimental sequela for cerebral metabolism as well. Furthermore, major depression and presumably chronic stress endanger susceptible brain areas mediated by a host of hormonal imbalances, particularly the HPA-axis dysregulation. Sociocultural and lifestyle factors like education, physical activity, diet and smoking may also modulate the individual risk affecting both reserve capacity and vulnerability. The pathophysiological relevance of trace metals, including aluminum and iron, is highly controversial; at any rate, they may adversely affect cellular defences, antioxidant competence in particular. The relative contribution of these factors, however, is as individual as the pattern of the factors. In familial AD, the genetic factors clearly drive the sequence of events. A strong interaction of fat metabolism and apoE polymorphism is suggested by intercultural epidemiological findings. In cultures, less plagued by the 'blessings' of the 'cafeteria diet-sedentary' Western lifestyle, apoE4 appears to be not a risk factor for AD. This intriguing evidence suggests that, analogous to cardiovascular diseases, apoE4 requires a hyperlipidaemic lifestyle to manifest as AD risk factor. Overall, the etiology of AD is a key paradigm for a gene-environment interaction. Copyright 2000 John Wiley & Sons, Ltd.
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Affiliation(s)
- Kurt Heininger
- Department of Neurology, Heinrich Heine University, Düsseldorf, Germany
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29
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Abstract
The results presented underline the fact that the nature and the concentration of the non-esterified fatty acids (NEFAs) liberated from membrane lipids, particularly the essential ones issued from lipid nutrition, clearly belong to a large group of factors (hormones, retinoids, growth factors, cytokines...) which control the shift between cell multiplication and differentiation. NEFAs act on this shift, per se or after being metabolized, by influencing, as second messengers or modulators, the intertwined mechanisms of action of growth factors and steroid hormones. These results may explain the molecular links which exist between endocrinology, oncology and nutrition.
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Affiliation(s)
- E A Nunez
- Laboratoire de Biochimie Endocrinienne, Faculté de Médecine X. Bichat, Université Denis Diderot, Paris, France
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30
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Nunez EA. Biological complexity is under the 'strange attraction' of non-esterified fatty acids. Prostaglandins Leukot Essent Fatty Acids 1997; 57:107-10. [PMID: 9250616 DOI: 10.1016/s0952-3278(97)90500-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It is now clear from numerous data that non-esterified fatty acids (NEFAs) can act without any metabolic modification as second messengers or modulators of the complex signalling network which is characteristic of mammals. This network can respond differently to adapt the organism to the various endogenous and exogenous environmental situations. NEFAs have a wide range of molecular structures, and thus can exert different specific modulatory actions on this signalling network, such as amplification, inhibition or signal redirection. We have chosen the term 'strange attractions' to describe these signalling modulations by analogy with the 'strange attractions' concept introduced in deterministic chaos theory. NEFAs can modulate the functions of mammals at all levels of organization (molecular, cellular, tissue, organ, etc).
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Affiliation(s)
- E A Nunez
- Laboratoire de Biochimie Endocrinienne, Faculté de Médecine X. Bichat, Université Denis Diderot, Paris, France
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31
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Abstract
Triglycerides, which are major constituents of dietary fat, contain a mixture of saturated and unsaturated fatty acids. One newly recognized function of unsaturated fatty acids is modulation of cell adhesion to components of the extracellular matrix. Alterations in cell adhesiveness or cell adhesion molecule expression accompany the onset of a number of diseases including arthritis, atherosclerosis, and cancer. Cell adhesion is necessary for the metastatic spread of cancer cells to new organs. Circulating cancer cells adhere to endothelial cells and the underlying subendothelial basement membrane as an initial step in the process of invading target organs during metastasis. Several recent studies have provided convincing evidence that unsaturated fatty acids and their metabolites influence adhesion of cultured human cancer cells to individual components of the basement membrane. These unsaturated fatty acid effects appear to be dependent in some instances on the expression of specific cell surface adhesion molecules. Unsaturated fatty acids influence the development of metastases in animal tumor models by largely unexplored mechanisms; the possibility that cell adhesion is involved in this process has not been thoroughly investigated. Future studies of unsaturated fatty acid effects on cell adhesion molecule expression in breast cancer patients should reveal the clinical relevance of the studies reviewed here.
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Affiliation(s)
- G L Johanning
- Department of Nutrition Sciences, University of Alabama-Birmingham 35294-3360, USA
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