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Arribas-Romano A, Fernández-Carnero J, Rodríguez-Lagos L, Molina-Álvarez M, Zabala-Zambrano J, Lezaun-Hernández L, Contreras-Padilla L, Mercado F. CPM-Related Mechanisms Could Play a Key Role in the Effects on Pain Sensitivity Induced by Manual Therapy: Three Crossover Trials Investigating the Effects of Manual Pressure. J Clin Med 2024; 13:3648. [PMID: 38999214 PMCID: PMC11242484 DOI: 10.3390/jcm13133648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/15/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
Objective: The aim of this study is to assess whether pain-inducing manual pressure (PIMP) leads to effects on pressure pain threshold (PPT) mediated by conditioned pain modulation (CPM) and whether these effects are influenced by the intensity and repetition of the stimulus. Additionally, the influence of psychological factors and physical activity on the response to PIMP was explored. Methods: A total of 72 pain-free students were randomly assigned to three crossover trials. Trial 1 compared the effects of PIMP with the cold pressor task and pain-inducing electrostimulation. Trial 2 compared the effects of manual pressure that elicited moderate pain, mild pain, and no pain. Trial 3 compared a single PIMP stimulation with four stimuli applied at the same site or at different sites. Results: PIMP produced a lower increase in PPT than cold pressor task and no difference with electrostimulation. Manual pressure that caused moderate pain led to a greater increase in PPT compared to mild pain and pain-free application. Repetition of PIMP stimulus, whether at the same or different sites, did not significantly increase PPT compared to a single stimulation. No association with psychological factors or physical activity was found. Conclusions: PIMP produces an increase in PPT, suggesting the involvement of CPM-related mechanisms.
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Affiliation(s)
- Alberto Arribas-Romano
- Escuela Internacional de Doctorado, Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, 28933 Madrid, Spain; (A.A.-R.); (L.R.-L.)
- Cognitive Neuroscience, Pain and Rehabilitation Research Group (NECODOR), Faculty of Health Sciences, Rey Juan Carlos University, 28922 Madrid, Spain; (M.M.-Á.); (F.M.)
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Rey Juan Carlos University, 28922 Madrid, Spain
| | - Josué Fernández-Carnero
- Cognitive Neuroscience, Pain and Rehabilitation Research Group (NECODOR), Faculty of Health Sciences, Rey Juan Carlos University, 28922 Madrid, Spain; (M.M.-Á.); (F.M.)
- Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Rey Juan Carlos University, 28922 Madrid, Spain
- Motion in Brains Research Group, Institute of Neuroscience and Movement Sciences (INCIMOV), Centro Superior de Estudios Universitarios La Salle, Universidad Autonoma de Madrid, 28049 Madrid, Spain; (J.Z.-Z.); (L.L.-H.)
- La Paz Hospital Institute for Health Research, IdiPAZ, 28029 Madrid, Spain
| | - Leonardo Rodríguez-Lagos
- Escuela Internacional de Doctorado, Department of Physical Therapy, Occupational Therapy, Rehabilitation and Physical Medicine, Universidad Rey Juan Carlos, 28933 Madrid, Spain; (A.A.-R.); (L.R.-L.)
- Cognitive Neuroscience, Pain and Rehabilitation Research Group (NECODOR), Faculty of Health Sciences, Rey Juan Carlos University, 28922 Madrid, Spain; (M.M.-Á.); (F.M.)
| | - Miguel Molina-Álvarez
- Cognitive Neuroscience, Pain and Rehabilitation Research Group (NECODOR), Faculty of Health Sciences, Rey Juan Carlos University, 28922 Madrid, Spain; (M.M.-Á.); (F.M.)
- Area of Pharmacology, Nutrition and Bromatology, Department of Basic Health Sciences, Rey Juan Carlos University, Unidad Asociada I+D+i Instituto de Química Médica (IQM) CSIC-URJC, 28922 Alcorcón, Spain
| | - Jesús Zabala-Zambrano
- Motion in Brains Research Group, Institute of Neuroscience and Movement Sciences (INCIMOV), Centro Superior de Estudios Universitarios La Salle, Universidad Autonoma de Madrid, 28049 Madrid, Spain; (J.Z.-Z.); (L.L.-H.)
- Advance Rehabilitation Center Sanitas, 28046 Madrid, Spain
| | - Lucas Lezaun-Hernández
- Motion in Brains Research Group, Institute of Neuroscience and Movement Sciences (INCIMOV), Centro Superior de Estudios Universitarios La Salle, Universidad Autonoma de Madrid, 28049 Madrid, Spain; (J.Z.-Z.); (L.L.-H.)
- Edurne Esquide Fisioterapia, 31200 Estella, Spain
| | - Lucía Contreras-Padilla
- iCentro Fix You, 28009 Madrid, Spain;
- School of Physiotherapy ONCE, Universidad Autónoma de Madrid, 28022 Madrid, Spain
| | - Francisco Mercado
- Cognitive Neuroscience, Pain and Rehabilitation Research Group (NECODOR), Faculty of Health Sciences, Rey Juan Carlos University, 28922 Madrid, Spain; (M.M.-Á.); (F.M.)
- Department of Psychology, Faculty of Health Sciences, Universidad Rey Juan Carlos, 28922 Madrid, Spain
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Sumizono M, Yoshizato Y, Imai T, Tani A, Nakanishi K, Nojima N, Kakimoto S, Sakakima H. Effects of Pain Relief Through Minimal Exercise Intervention in a Rat Model of Neuropathic Pain. Cureus 2024; 16:e62897. [PMID: 39044893 PMCID: PMC11262913 DOI: 10.7759/cureus.62897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2024] [Indexed: 07/25/2024] Open
Abstract
We aimed to minimize the frequency of exercise intervention and test the efficacy of pain relief. We also investigated the mechanism of neuropathic pain to determine the best frequency of pain relief for neuropathic pain. The chronic constriction injury (CCI) rat model was randomly divided into three groups: exercise (Ex), No-Ex, and normal. The treadmill exercise intervention was administered, and the 50% withdrawal threshold was assessed using the Von Frey Test. Ionized calcium-binding adaptor molecule 1 (IBA1), glial fibrillary acidic protein (GFAP), brain-derived neurotrophic factor (BDNF), C-C chemokine receptor type 2 (CCR2), and tumor necrosis factor receptor-associated factor 6 (TRAF6) activation was determined through immunohistochemistry. In the brain, we examined the increased expression of β-endorphin/met-enkephalin in the gray matter of the midbrain aqueduct. Co-expression of CCR2, IBA1, and Neu-N was observed in the spinal cord dorsal horn by immunofluorescence staining. The 50% pain response threshold was significantly lower in the Ex group than in the No-Ex group at five weeks post-CCI, indicating a high analgesic effect. In the dorsal horn of the spinal cord, IBA1 and GFAP were significantly decreased in the Ex group than in the No-Ex group at five weeks post-CCI. However, no significant difference in activation of BDNF, CCR2, and TRAF6 was observed. In the midbrain, the Ex group showed a significant increase compared to the No-Ex group. In summary, our results suggest that in minimal-exercise intervention, neuropathic pain relief is achieved by activation of the descending pain inhibitory system in the midbrain.
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Affiliation(s)
- Megumi Sumizono
- Rehabilitation, Kyushu University of Nursing and Social Welfare, Tamana, JPN
- Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, JPN
| | - Yushin Yoshizato
- Rehabilitation, Kyushu University of Nursing and Social Welfare, Tamana, JPN
| | - Takaki Imai
- Rehabilitation, Kyushu University of Nursing and Social Welfare, Tamana, JPN
| | - Akira Tani
- Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, JPN
| | - Kazuki Nakanishi
- Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, JPN
| | - Nao Nojima
- Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, JPN
| | - Shogo Kakimoto
- Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, JPN
| | - Harutoshi Sakakima
- Physical Therapy, School of Health Sciences, Kagoshima University, Kagoshima, JPN
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Su SC, Hung YJ, Lin FH, Hsieh CH, Lu CH, Chien CY, Chen YC, Li PF, Kuo FC, Liu JS, Chu NF, Lee CH. Circulating protein disulfide isomerase family member 4 is associated with type 2 diabetes mellitus, insulin sensitivity, and obesity. Acta Diabetol 2022; 59:1001-1009. [PMID: 35460376 DOI: 10.1007/s00592-022-01892-1] [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: 12/04/2021] [Accepted: 04/09/2022] [Indexed: 11/01/2022]
Abstract
AIMS Endoplasmic reticulum (ER) stress is associated with obesity and type 2 diabetes mellitus (T2DM) and increasing evidence demonstrates that some ER stress markers can represent the severity of metabolic dysfunction in either cellular or animal models. However, no appropriate molecule has been identified to demonstrate these relationships in clinical practice. METHODS To determine whether the serum level of the ER chaperone, protein disulfide isomerase family A, member 4 (PDIA4), is associated with type 2 diabetes mellitus, obesity, and insulin sensitivity, we conducted a cross-sectional study for which a total of 553 adults, including 159 with normal glucose tolerance (NGT), 169 with prediabetes (Pre-DM), and 225 with newly diagnosed T2DM, were recruited. RESULTS Serum PDIA4 levels were significantly higher in patients with T2DM than in those with NGT (P < 0.001), even after adjustment for potential confounders. These levels correlated positively with fasting plasma glucose, BMI, waist circumference as well as high-sensitivity C-reactive protein levels, and negatively and strongly correlated with insulin sensitivity. In a multivariate logistic regression analysis, higher serum PDIA4 concentration was observed to be significantly associated with an increased risk of T2DM. CONCLUSIONS Our findings provide new mechanistic insights linking ER stress, T2DM, insulin sensitivity, and obesity, which may, in part, account for the ER chaperone properties associated with PDIA4. The results suggest that PDIA4 may serve as a potential instigator of and a putative therapeutic target for T2DM.
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Affiliation(s)
- Sheng-Chiang Su
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Yi-Jen Hung
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
- Department and Graduate Institute of Biochemistry, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Fu-Huang Lin
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Chang-Hsun Hsieh
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Chieh-Hua Lu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Chu-Yen Chien
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Ying-Chen Chen
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Peng-Fei Li
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Feng-Chih Kuo
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Jhih-Syuan Liu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Nain-Feng Chu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC
| | - Chien-Hsing Lee
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, ROC.
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd, Neihu District, Taipei City, 114, Taiwan, ROC.
- Department and Graduate Institute of Biochemistry, National Defense Medical Center, Taipei, Taiwan, ROC.
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Saanijoki T, Kantonen T, Pekkarinen L, Kalliokoski K, Hirvonen J, Malén T, Tuominen L, Tuulari JJ, Arponen E, Nuutila P, Nummenmaa L. Aerobic Fitness Is Associated with Cerebral μ-Opioid Receptor Activation in Healthy Humans. Med Sci Sports Exerc 2022; 54:1076-1084. [PMID: 35195103 DOI: 10.1249/mss.0000000000002895] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Central μ-opioid receptors (MORs) modulate affective responses to physical exercise. Individuals with higher aerobic fitness report greater exercise-induced mood improvements than those with lower fitness, but the link between cardiorespiratory fitness and the MOR system remains unresolved. Here we tested whether maximal oxygen uptake (V̇O2peak) and physical activity level are associated with cerebral MOR availability and whether these phenotypes predict endogenous opioid release after a session of exercise. METHODS We studied 64 healthy lean men who performed a maximal incremental cycling test for V̇O2peak determination, completed a questionnaire assessing moderate-to-vigorous physical activity (MVPA; in minutes per week), and underwent positron emission tomography with [11C]carfentanil, a specific radioligand for MOR. A subset of 24 subjects underwent additional positron emission tomography scan also after a 1-h session of moderate-intensity exercise and 12 of them also after a bout of high-intensity interval training. RESULTS Higher self-reported MVPA level predicted greater opioid release after high-intensity interval training, and both V̇O2peak and MVPA level were associated with a larger decrease in cerebral MOR binding after aerobic exercise in the ventral striatum, orbitofrontal cortex, and insula. That is, more trained individuals showed greater opioid release acutely after exercise in brain regions especially relevant for reward and cognitive processing. Fitness was not associated with MOR availability. CONCLUSIONS We conclude that regular exercise training and higher aerobic fitness may induce neuroadaptation within the MOR system, which might contribute to improved emotional and behavioral responses associated with long-term exercise.
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Affiliation(s)
| | | | | | | | | | - Tuulia Malén
- Turku PET Centre, University of Turku, Turku, FINLAND
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Hendijani F, Hosseini FS. Interindividual variability in diabetic patients’ response to opium poppy: an overview of impressive factors. Per Med 2022; 19:155-163. [PMID: 35220727 DOI: 10.2217/pme-2021-0107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Diabetic patients always seek alternative treatments to lower their blood glucose level efficiently, because antidiabetic drugs produce adverse effects and many patients experience reduced response after a treatment period. Opium poppy ( Papaver somniferum) is frequently consumed by diabetic patients for reduction of blood glucose level. Scientific studies found controversial results in the investigation of the blood glucose-lowering effects of opium poppy. In this regard, we explored the antidiabetic effect of opium poppy more closely. The antidiabetic or antihyperglycemic effect of P. somniferum alkaloids were reviewed. Next, opioid receptors and their role in diabetes were explored. In the final part origins of interindividual variabilities in opioid receptors and metabolizing enzymes’ functions including genetic and epigenetic factors were reviewed.
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Affiliation(s)
- Fatemeh Hendijani
- Department of Pharmacognosy & Pharmaceutical Biotechnology, Faculty of Pharmacy, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Fatemeh Sadat Hosseini
- Student Research Committee, Faculty of Pharmacy, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
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Tavassoli H, Heidarianpour A, Hedayati M. The effects of resistance exercise training followed by de-training on irisin and some metabolic parameters in type 2 diabetic rat model. Arch Physiol Biochem 2022; 128:240-247. [PMID: 31588806 DOI: 10.1080/13813455.2019.1673432] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND We investigated the effects of high-fat diet (HFD) consumption combined with diabetes induction, resistance exercise training (RET) and a de-training period on circulating irisin levels and selective metabolic parameters. MATERIAL AND METHODS Rats were assigned to four groups (n = 8): healthy non-diabetic rats (NDC), non-diabetic rats that performed RET (NDR), sedentary HFD-fed/STZ-treated rats (HFD/STZ) and HFD-fed/STZ-treated rats that performed RET (HFD/STZ + RE). RESULTS HFD consumption reduced irisin level and Quicki (p < .01). After the 12-week period, levels of TC, TG, HOMA1-IR, HOMA2-IR and irisin were also lower in the HFD/STZ + RE group compared to the HFD/STZ group. Body weight and HOMA1-IR showed a positive (r = 0.558 and r = 0.538) whereas TC and LDL-C had a negative correlation (r = -0.461 and r = -0.630) with irisin level (p < .05). CONCLUSIONS Irisin level increased along with the progress of obesity and T2DM. It seems that RET can attenuate the increase of irisin in those conditions by improvement of glucose/lipid metabolic disorders.
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Affiliation(s)
- Hassan Tavassoli
- Department of Exercise Physiology, Faculty of Physical Education and Sport Science, Bu-Ali Sina University, Hamedan, Iran
| | - Ali Heidarianpour
- Department of Exercise Physiology, Faculty of Physical Education and Sport Science, Bu-Ali Sina University, Hamedan, Iran
| | - Mehdi Hedayati
- Cellular and Molecular Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Raoof M, Shakoori A, Kooshki R, Abbasnejad M, Amanpour S. The effects of regular exercise on capsaicin-induced pulpal pain and pain-induced changes in passive avoidance learning and memory in rats. Korean J Pain 2017; 30:258-264. [PMID: 29123620 PMCID: PMC5665737 DOI: 10.3344/kjp.2017.30.4.258] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/25/2017] [Accepted: 07/27/2017] [Indexed: 11/07/2022] Open
Abstract
Background Pulpal pain is one of the most common and severe orofacial pain conditions with considerable adverse effects on physiological processes including learning and memory. Regular exercise is known to be effective on cognitive function as well as pain processing in the central nervous system. Here, the possible effects of regular exercise on pulpal pain response as well as pain-induced changes in learning and memory efficiency in rats were investigated. Methods Twenty-four male Wistar rats were randomly assigned to the control, capsaicin, exercise, and exercise plus capsaicin groups. Rats in exercise groups were forced to run on a treadmill with a moderate exercise protocol for 4 weeks. Capsaicin was used to induce dental pulp pain. Passive avoidance learning and memory performance was assessed by using a shuttle box apparatus. Results According to the results, regular exercise could decrease the time course of capsaicin-induced pulpal pain (P < 0.001). Moreover, in capsaicin-treated rats, passive avoidance acquisition was impaired as compared to the control (P < 0.05) and exercise (P < 0.001) groups. Additionally, regular exercise before capsaicin injection could attenuate capsaicin-induced memory impairments (P < 0.05). Conclusions Taken together, the present data showed that regular exercise has inhibitory effects on capsaicin-induced pulpal pain as well as pain-induced cognitive dysfunction in rats.
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Affiliation(s)
- Maryam Raoof
- Endodontology Research Center, Kerman University of Medical Sciences, Kerman, Iran.,Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Afshin Shakoori
- Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran
| | - Razieh Kooshki
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Iran
| | - Mehdi Abbasnejad
- Department of Biology, Faculty of Sciences, Shahid Bahonar University of Kerman, Iran
| | - Sara Amanpour
- Oral and Dental Diseases Research Center, Kerman University of Medical Sciences, Kerman, Iran.,Kerman Social Determinants on Oral Health Research Center, Kerman University of Medical Sciences, Kerman, Iran
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Rizi AA, Reisi P, Naghsh N. Effect of forced treadmill exercise and blocking of opioid receptors with naloxone on memory in male rats. Adv Biomed Res 2016; 5:20. [PMID: 26962522 PMCID: PMC4770631 DOI: 10.4103/2277-9175.175906] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 09/08/2015] [Indexed: 12/16/2022] Open
Abstract
Background: The forced treadmill running can influence the opioid contents of the brain, through both effects of exercise and the effects of stress caused by coercion. Since opioids can cause negative effects on brain functions, this study aimed to evaluate the effect of forced treadmill exercise and blocking of opioid receptors with naloxone on memory in male rats. Materials and Methods: Experimental groups were the control, the exercise, the naloxone, and the naloxone exercise. The exercise program was treadmill running at 22 m/min at 0° inclination for 50 min/day, 6 days/week, for 4 weeks. Naloxone (1 mg/kg) was injected 5 min before the treadmill running. Morris water maze and passive avoidance learning tests were used for evaluation of memory. Acquisition phase of both tests was performed before interventions, and memory was evaluated 1-day and 1-week after the last session of exercise and treatments. Results: Our data showed that forced exercise impaired performance in passive avoidance learning test (P < 0.05 and P <0.01, 1-day, and 1-week after the last session of exercise and treatments, respectively). Spatial memory was only impaired after 1-week in the exercise group. Naloxone had no significant effect on memory in the control group. However, it improved memory in the exercise group, as there was no significant difference between the control and the naloxone exercise in both tests. Conclusion: The data correspond to the possibility that opioidergic system may have mediatory roles in exercise-induced responses in forced exercise. These roles are likely harmful for memory.
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Affiliation(s)
- Atefeh Asadi Rizi
- Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
| | - Parham Reisi
- Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; Applied Physiology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Biosensor Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nooshin Naghsh
- Department of Biology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran
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Yin J, Kuang J, Chandalia M, Tuvdendorj D, Tumurbaatar B, Abate N, Chen JDZ. Hypoglycemic effects and mechanisms of electroacupuncture on insulin resistance. Am J Physiol Regul Integr Comp Physiol 2014; 307:R332-9. [PMID: 24848362 DOI: 10.1152/ajpregu.00465.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The aim of this study was to investigate effects and mechanisms of electroacupuncture (EA) on blood glucose and insulin sensitivity in mice fed a high-fat diet. Both wild-type (WT) and adipose ectonucleotide pyrophosphate phosphodiesterase (ENPP1) transgenic (TG) mice were fed a high-fat diet for 12 wk; for each mouse, an intraperitoneal glucose tolerance test (IPGTT) and insulin tolerance test (ITT) were performed with or without EA at abdomen or auricular areas. A high-fat diet-induced insulin resistance in both WT and TG mice. In the WT mice, EA at 3 Hz and 15 Hz, but not at 1 Hz or 100 Hz, via CV4+CV12 significantly reduced postprandial glucose levels; EA at 3 Hz was most potent. The glucose level was reduced by 61.7% at 60 min and 74.5% at 120 min with EA at 3 Hz (all P < 0.001 vs. control). Similar hypoglycemic effect was noted in the TG mice. On the contrary, EA at auricular points increased postprandial glucose level (P < 0.03). 4). EA at 3 Hz via CV4+CV12 significantly enhanced the decrease of blood glucose after insulin injection, suggesting improvement of insulin sensitivity. Plasma free fatty acid was significantly suppressed by 42.5% at 15 min and 50.8% at 30 min with EA (P < 0.01) in both WT and TG mice. EA improves glucose tolerance in both WT and TG mice fed a high-fat diet, and the effect is associated with stimulation parameters and acupoints and is probably attributed to the reduction of free fatty acid.
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Affiliation(s)
- Jieyun Yin
- Division of Gastroenterology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas
| | - Jian Kuang
- Division of Gastroenterology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas; Division of Endocrinology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, People's Republic of China; and
| | - Manisha Chandalia
- Division of Endocrinology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas
| | - Demidmaa Tuvdendorj
- Division of Endocrinology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas
| | - Batbayar Tumurbaatar
- Division of Endocrinology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas
| | - Nicola Abate
- Division of Endocrinology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas
| | - Jiande D Z Chen
- Division of Gastroenterology, Department of Internal Medicine. University of Texas Medical Branch, Galveston, Texas; Ningbo Pace Translational Medical Research Center, Ningbo, China
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Vachon P, Millecamps M, Low L, Thompsosn SJ, Pailleux F, Beaudry F, Bushnell CM, Stone LS. Alleviation of chronic neuropathic pain by environmental enrichment in mice well after the establishment of chronic pain. Behav Brain Funct 2013; 9:22. [PMID: 24025218 PMCID: PMC3679946 DOI: 10.1186/1744-9081-9-22] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 05/31/2013] [Indexed: 12/21/2022] Open
Abstract
Background In animal models, the impact of social and environmental manipulations on chronic pain have been investigated in short term studies where enrichment was implemented prior to or concurrently with the injury. The focus of this study was to evaluate the impact of environmental enrichment or impoverishment in mice three months after induction of chronic neuropathic pain. Methods Thirty-four CD-1 seven to eight week-old male mice were used. Mice underwent surgery on the left leg under isoflurane anesthesia to induce the spared nerve injury model of neuropathic pain or sham condition. Mice were then randomly assigned to one of four groups: nerve injury with enriched environment (n = 9), nerve injury with impoverished environment (n = 8), sham surgery with enriched environment (n = 9), or sham surgery with impoverished environment (n = 8). The effects of environmental manipulations on mechanical (von Frey filaments) heat (hot plate) and cold (acetone test) cutaneous hypersensitivities, motor impairment (Rotarod), spontaneous exploratory behavior (open field test), anxiety-like behavior (elevated plus maze) and depression-like phenotype (tail suspension test) were assessed in neuropathic and control mice 1 and 2 months post-environmental change. Finally, the effect of the environment on spinal expression of the pro-nociceptive neuropeptides substance P and CGRP form the lumbar spinal cord collected at the end of the study was evaluated by tandem liquid chromatography mass spectrometry. Results Environmental enrichment attenuated nerve injury-induced hypersensitivity to mechanical and cold stimuli. In contrast, an impoverished environment exacerbated mechanical hypersensitivity. No antidepressant effects of enrichment were observed in animals with chronic neuropathic pain. Finally, environmental enrichment resulted lower SP and CGRP concentrations in neuropathic animals compared to impoverishment. These effects were all observed in animals that had been neuropathic for several months prior to intervention. Conclusions These results suggest that environmental factors could play an important role in the rehabilitation of chronic pain patients well after the establishment of chronic pain. Enrichment is a potentially inexpensive, safe and easily implemented non-pharmacological intervention for the treatment of chronic pain.
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Affiliation(s)
- Pascal Vachon
- Department of Veterinary Biomedicine, University of Montreal, Faculty of Veterinary Medicine, St-Hyacinthe, Quebec, Canada.
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Cheng KC, Asakawa A, Li YX, Liu IM, Amitani H, Cheng JT, Inui A. Opioid μ-receptors as new target for insulin resistance. Pharmacol Ther 2013; 139:334-40. [PMID: 23688574 DOI: 10.1016/j.pharmthera.2013.05.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 10/26/2022]
Abstract
Type-2 diabetes is one of the fastest growing public health problems worldwide resulting from both environmental and genetic factors. Activation of μ-opioid receptor (MOR) could result in reversal of the impairment of insulin-stimulated glucose disposal in genetically obese Zucker rats via exercise training. This improvement of insulin resistance was associated with an elevation of circulating β-endorphin to ameliorate the post-receptor insulin signaling cascade, including downstream effectors of the phosphatidylinositol 3-kinase (PI3-kinase) signaling pathway. In insulin resistant rats, Loperamide treatment effected on the insulin receptor substrate (IRS)-1/PI3-kinase/Akt signaling cascade and subsequent insulin-stimulated glucose transport trafficking on skeletal muscle, which were all suppressed by MOR antagonism. In addition, induction of insulin resistance by the intake of high fructose is more rapid in MOR knockout mice than in wild-type mice. Improvements in insulin sensitivity through the peripheral MOR activation overcoming defects related to the post-receptor in IRS-1-associated PI3-kinase step have been defined. Opioid receptor activation, especially of the μ-subtype, may provide merits in the amelioration of defective insulin action. Atypical zeta (ζ) isoform of protein kinase C serves as a factor that integrates with peripheral MOR pathway and insulin signals for glucose utilization. The developments call new insights into the chemical compounds and/or herbal products that might enhance opioid peptide secretion and/or stimulate MOR in peripheral insulin-sensitive tissues to serve as potential agents or adjuvants for helping the glucose metabolism. In the present review, we update these topics and discuss the concept of targeting peripheral MOR pathway for the treatment of insulin resistance.
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Affiliation(s)
- Kai-Chun Cheng
- Department of Psychosomatic Internal Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8520, Japan
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Abstract
Migraine and metabolic syndrome are highly prevalent and costly conditions. The two conditions coexist, but it is unclear what relationship may exist between the two processes. Metabolic syndrome involves a number of findings, including insulin resistance, systemic hypertension, obesity, a proinflammatory state, and a prothrombotic state. Only one study addresses migraine in metabolic syndrome, finding significant differences in the presentation of metabolic syndrome in migraineurs. However, controversy exists regarding the contribution of each individual risk factor to migraine pathogenesis and prevalence. It is unclear what treatment implications, if any, exist as a result of the concomitant diagnosis of migraine and metabolic syndrome. The cornerstone of migraine and metabolic syndrome treatments is prevention, relying heavily on diet modification, sleep hygiene, medication use, and exercise.
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Affiliation(s)
- Amit Sachdev
- Department of Neurology, Jefferson Headache Center, Thomas Jefferson University Philadelphia, PA, USA
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Yadav RK, Magan D, Mehta N, Sharma R, Mahapatra SC. Efficacy of a Short-Term Yoga-Based Lifestyle Intervention in Reducing Stress and Inflammation: Preliminary Results. J Altern Complement Med 2012; 18:662-7. [DOI: 10.1089/acm.2011.0265] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Raj Kumar Yadav
- Integral Health Clinic, Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
| | - Dipti Magan
- Integral Health Clinic, Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
| | - Nalin Mehta
- Integral Health Clinic, Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
| | - Ratna Sharma
- Integral Health Clinic, Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
| | - Sushil Chandra Mahapatra
- Integral Health Clinic, Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
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Tzeng TF, Liou SS, Liu IM. Myricetin Ameliorates Defective Post-Receptor Insulin Signaling via β-Endorphin Signaling in the Skeletal Muscles of Fructose-Fed Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 2011:150752. [PMID: 21785619 PMCID: PMC3136182 DOI: 10.1093/ecam/neq017] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2009] [Accepted: 01/25/2010] [Indexed: 01/05/2023]
Abstract
β-Endorphin plays a major role in the amelioration of insulin resistance. The present study documents that myricetin (3,5,7,3′, 4′, 5′-hexahydroxyflavone) ameliorates insulin resistance by enhancing β-endorphin production in insulin-resistant rats. The rats were induced for insulin resistance by feeding them a diet containing 60% fructose for 6 weeks. The degree of insulin resistance was measured by the homeostasis model assessment of basal insulin resistance (HOMA-IR). The plasma levels of insulin and β-endorphin were measured by an enzyme-linked immunosorbent assay. The insulin receptor-related signaling mediators in the soleus muscles of rats were evaluated by immunoprecipitation or immunoblotting. Myricetin was injected daily (1 mg kg−1 per injection, thrice daily) for 14 days. Consequently, the high-glucose plasma levels in fructose-fed rats decreased significantly concomitant with an increase in plasma β-endorphin. The reduction of the elevated HOMA-IR index following treatment with myricetin was subsequently inhibited by the administration of β-funaltrexamine hydrochloride (β-FNA) at doses sufficient to block μ-opioid receptors (MOR). The myricetin treatment was also observed to affect the phosphorylation of the insulin receptor, insulin receptor substrate-1, Akt and Akt substrate of 160 kDa, with subsequent effects on glucose-transporter subtype 4 translocation, all of which were blocked by β-FNA pretreatment. These results indicated that enhancement of β-endorphin secretion, which in turn leads to peripheral MOR activation, is involved in the action of myricetin on the amelioration of impaired signaling intermediates downstream of insulin receptors.
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Affiliation(s)
- Thing-Fong Tzeng
- Department of Internal Medicine, Pao Chien Hospital, Ping Tung City, China
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15
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Regular exercise reverses sensory hypersensitivity in a rat neuropathic pain model: role of endogenous opioids. Anesthesiology 2011; 114:940-8. [PMID: 21386701 DOI: 10.1097/aln.0b013e318210f880] [Citation(s) in RCA: 213] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Exercise is often prescribed as a therapy for chronic pain. Short-term exercise briefly increases the production of endogenous analgesics, leading to transient antinociception. In limited studies, exercise produced sustained increases in endogenous opioids, sustained analgesia, or diminished measures of chronic pain. This study tests the hypothesis that regular aerobic exercise leads to sustained reversal of neuropathic pain by activating endogenous opioid-mediated pain modulatory systems. METHODS After baseline measurements, the L5 and L6 spinal nerves of male Sprague-Dawley rats were tightly ligated. Animals were randomized to sedentary or 5-week treadmill exercise-trained groups. Thermal and tactile sensitivities were assessed 23 h after exercise, using paw withdrawal thresholds to von Frey filaments and withdrawal latencies to noxious heat. Opioid receptor antagonists were administered by subcutaneous, intrathecal, or intracerebroventricular injection. Opioid peptides were quantified using immunohistochemistry with densitometry. RESULTS Exercise training ameliorated thermal and tactile hypersensitivity in spinal nerve-ligated animals within 3 weeks. Sensory hypersensitivity returned 5 days after discontinuation of exercise training. The effects of exercise were reversed by using systemically or intracerebroventricularly administered opioid receptor antagonists and prevented by continuous infusion of naltrexone. Exercise increased β-endorphin and met-enkephalin content in the rostral ventromedial medulla and the mid-brain periaqueductal gray area. CONCLUSIONS Regular moderate aerobic exercise reversed signs of neuropathic pain and increased endogenous opioid content in brainstem regions important in pain modulation. Exercise effects were reversed by opioid receptor antagonists. These results suggest that exercise-induced reversal of neuropathic pain results from an up-regulation of endogenous opioids.
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Abstract
OBJECTIVE To review the current research of new emerging diagnostic technology for non-invasive physiological monitoring of exercise and fitness. As a personal trainer, I believe that exercise can improve the conditions of several diseases and/or events such as stroke, post-traumatic head injury, spinal cord injury, and a multitude of other diseases. This compilation of information will allow health care providers tools of a non-invasive manner to promote healing and health that go beyond the initial event. Allowing patients continued managed care beyond what is believed to be their plateau. MATERIAL AND METHOD Review science-based research involving non-invasive technology, including cardiovascular evaluations: heart rate monitors, near-infrared spectroscopy, blood pressure, and electrocardiography; motor capabilities: surface electromyography and manual testers, i.e. dynamometer, and digital and video photography; radiological monitoring: magnetic resonance imaging, three-dimensional computer tomography, and laser Doppler. RESULTS This investigation has found that a new approach should be implemented for non-invasive physiological monitoring of exercise and fitness through development and utilization across a wide variety of equipment, and monitoring technology. This non-invasive methodology will not only motivate but encourage individuals to begin and remain compliant with an exercise program allowing a variety of health care providers to assist in patient care. DISCUSSION We need to shift the paradigm from taking care of the sick to maintaining the health of our patients. This can be accomplished with non-invasive evaluation, tracking, and monitoring tools. Many of the suggestions for monitoring are used in a clinical setting rather than a general fitness environment. These monitoring tests need to be economical as well as available for continual re-evaluation.
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Scomparin DX, Grassiolli S, Gomes RM, Torrezan R, de Oliveira JC, Gravena C, Pêra CC, Mathias PCDF. Low-Intensity swimming training after weaning improves glucose and lipid homeostasis in MSG hypothalamic obese mice. Endocr Res 2011; 36:83-90. [PMID: 21539446 DOI: 10.3109/07435800.2010.534750] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Low-intensity swimming training, started at an early age, was undertaken to observe glycemic control in hypothalamic obese mice produced by neonatal monosodium l-glutamate (MSG) treatment. Although swimming exercises by weaning pups inhibited hypothalamic obesity onset and recovered sympathoadrenal axis activity, this event was not observed when exercise training is applied to young adult mice. However, the mechanisms producing this improved metabolism are still not fully understood. Current work verifies whether, besides reducing fat tissue accumulation, low-intensity swimming in MSG-weaned mice also improves glycemic control. Although MSG and control mice swam for 15 min/day, 3 days a week, from the weaning stage up to 90 days old, sedentary MSG and normal mice did not exercise at all. After 14 h of fasting, animals were killed at 90 days of age. Retroperitonial fat accumulation was measured to estimate obesity. Fasting blood glucose and insulin concentrations were also measured. Mice were also submitted to ipGTT. MSG obese mice showed fasting hyperglycemia, hyperinsulinemia, and glucose intolerance and insulin resistance. However, the exercise was able to block MSG treatment effects. Higher total cholesterol and triglycerides observed in MSG mice were normalized by exercise after weaning. Exercised MSG animals had higher HDLc than the sedentary group. Data suggest that early exercise training maintains normoglycemia, insulin tissue sensitivity, and normal lipid profile in mice programmed to develop metabolic syndrome.
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Affiliation(s)
- Dionízia Xavier Scomparin
- Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Paraná, Brazil
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18
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Metabolic syndrome: Aggression control mechanisms gone out of control. Med Hypotheses 2010; 74:578-89. [DOI: 10.1016/j.mehy.2009.09.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Accepted: 09/07/2009] [Indexed: 01/13/2023]
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Hegadoren KM, O'Donnell T, Lanius R, Coupland NJ, Lacaze-Masmonteil N. The role of beta-endorphin in the pathophysiology of major depression. Neuropeptides 2009; 43:341-53. [PMID: 19647870 DOI: 10.1016/j.npep.2009.06.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2009] [Revised: 06/04/2009] [Accepted: 06/25/2009] [Indexed: 12/19/2022]
Abstract
A role for beta-endorphin (beta-END) in the pathophysiology of major depressive disorder (MDD) is suggested by both animal research and studies examining clinical populations. The major etiological theories of depression include brain regions and neural systems that interact with opioid systems and beta-END. Recent preclinical data have demonstrated multiple roles for beta-END in the regulation of complex homeostatic and behavioural processes that are affected during a depressive episode. Additionally, beta-END inputs to regulatory pathways involving feeding behaviours, motivation, and specific types of motor activity have important implications in defining the biological foundations for specific depressive symptoms. Early research linking beta-END to MDD did so in the context of the hypothalamic-pituitary-adrenal (HPA) axis activity, where it was suggested that HPA axis dysregulation may account for depressive symptoms in some individuals. The primary aims of this paper are to use both preclinical and clinical research (a) to critically review data that explores potential roles for beta-END in the pathophysiology of MDD and (b) to highlight gaps in the literature that limit further development of etiological theories of depression and testable hypotheses. In addition to examining methodological and theoretical challenges of past clinical studies, we summarize studies that have investigated basal beta-END levels in MDD and that have used challenge tests to examine beta-END responses to a variety of experimental paradigms. A brief description of the synthesis, location in the CNS and behavioural pharmacology of this neuropeptide is also provided to frame this discussion. Given the lack of clinical improvement observed with currently available antidepressants in a significant proportion of depressed individuals, it is imperative that novel mechanisms be investigated for antidepressant potential. We conclude that the renewed interest in elucidating the role of beta-END in the pathophysiology of MDD must be paralleled by consensus building within the research community around the heterogeneity inherent in mood disorders, standardization of experimental protocols, improved discrimination of POMC products in analytical techniques and consistent attention paid to important confounds like age and gender.
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Affiliation(s)
- K M Hegadoren
- Faculty of Nursing, University of Alberta, Edmonton, AB, Canada T6G 2G3.
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20
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Su CH, Liu IM, Chung HH, Cheng JT. Activation of I2-imidazoline receptors by agmatine improved insulin sensitivity through two mechanisms in type-2 diabetic rats. Neurosci Lett 2009; 457:125-8. [DOI: 10.1016/j.neulet.2009.03.093] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Accepted: 03/25/2009] [Indexed: 11/26/2022]
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Williams J, Haller VL, Stevens DL, Welch SP. Decreased basal endogenous opioid levels in diabetic rodents: Effects on morphine and delta-9-tetrahydrocannabinoid-induced antinociception. Eur J Pharmacol 2008; 584:78-86. [DOI: 10.1016/j.ejphar.2007.12.035] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 12/11/2007] [Accepted: 12/20/2007] [Indexed: 10/22/2022]
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Tzeng TF, Lo CY, Cheng JT, Liu IM. Activation of μ-opioid receptors improves insulin sensitivity in obese Zucker rats. Life Sci 2007; 80:1508-16. [PMID: 17316705 DOI: 10.1016/j.lfs.2007.01.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2006] [Revised: 12/30/2006] [Accepted: 01/12/2007] [Indexed: 11/22/2022]
Abstract
In the current study we investigated the effect of mu-opioid receptor activation on insulin sensitivity. In obese Zucker rats, an intravenous injection of loperamide (18 microg/kg, three times daily for 3 days) decreased plasma glucose levels and the glucose-insulin index. Both effects of loperamide were subsequently inhibited by the administration of 10 microg/kg of naloxone or 10 microg/kg of naloxonazine, doses sufficient to block mu-opioid receptors. Other metabolic defects characteristic of obese Zucker rats, such as defects in insulin signaling, the decreased expression of insulin receptor substrate (IRS)-1, the p85 regulatory subunit of phosphatidylinositol 3-kinase (PI3 kinase), and the glucose transporter subtype 4 (GLUT 4), and the reduction of phosphorylation in IRS-1 or Akt serine, were also studied. These defects were all reversed by loperamide treatment in a dose which overcame mu-opioid receptor blockade. Moreover, loss of tolbutamide-induced plasma glucose lowering action (10 mg/kg) in wild-type mice given a fructose-rich diet was markedly delayed by repeated treatment with loperamide; however, this delay induced by loperamide did not occur in mu-opioid receptor knockout mice. These results indicate an important role of peripheral mu-opioid receptors in the loperamide-induced improvement of insulin sensitivity. Our results suggest that activation of peripheral mu-opioid receptors can ameliorate insulin resistance in animals, and provide a new target for therapy of insulin resistance.
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Affiliation(s)
- Thing-Fong Tzeng
- Department of Internal Medicine, Pao Chien Hospital, Ping Tung City, Taiwan, ROC
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23
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Abstract
This paper is the 28th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning over a quarter-century of research. It summarizes papers published during 2005 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity, neurophysiology and transmitter release (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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24
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Chang SP, Chen YH, Chang WC, Liu IM, Cheng JT. Merit of physical exercise to reverse the higher gene expression of hepatic phosphoenolpyruvate carboxykinase in obese Zucker rats. Life Sci 2006; 79:240-6. [PMID: 16458327 DOI: 10.1016/j.lfs.2005.12.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Revised: 11/11/2005] [Accepted: 12/28/2005] [Indexed: 10/25/2022]
Abstract
Effects of endurance training on the phosphoenolpyruvate carboxykinase (PEPCK), a rate-limiting enzyme of gluconeogenesis, were studied in the obese Zucker rats. We used a moderate exercise program consisting of treadmill running at 20 m/min and 0-degree gradient for 1 h/day, 7 days/week, for 8 weeks. At the end of the experimental period, insulin action on glucose disposal rate was measured using the glucose-insulin index, the product of the areas under the curve of glucose and insulin during the intraperitoneal glucose tolerance test. Furthermore, changes of hepatic PEPCK gene expression were detected using reverse transcriptase polymerase chain reaction to assay the mRNA level and Western blot analysis to detect the protein level. Different to sedentary obese rats, an elevation in the value of glucose-insulin index from the exercised obese rats declined, indicating the marked effect of regular moderate exercise on the improvement of insulin sensitivity in this insulin resistant animal model. Moreover, the diabetes-related elevation in mRNA level and protein content of hepatic PEPCK were observed in non-exercise obese groups but they were markedly reduced by exercise training. In addition, chronic exercise training enhanced the insulin sensitivity of lean Zucker rats, since the value of glucose-insulin index was lower than that of untrained lean groups. Also, the hepatic PEPCK gene expressions both the mRNA and protein levels were reduced in exercised lean Zucker rats as compared with their sedentary littermates. These results suggest that modulation of hepatic PEPCK gene expression by chronic exercise training might be related to the enhancement of insulin sensitivity. Thus, endurance exercise training could aid in the prevention and/or treatment of individuals with insulin resistance.
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Affiliation(s)
- Shih-Pei Chang
- Department of Physical Education and Department of Medical Technology, Centre Taiwan University of Science and Technology, Taichung City 40601, Taiwan
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Chang SL, Lin KJ, Lin RT, Hung PH, Lin JG, Cheng JT. Enhanced insulin sensitivity using electroacupuncture on bilateral Zusanli acupoints (ST 36) in rats. Life Sci 2006; 79:967-71. [PMID: 16762373 DOI: 10.1016/j.lfs.2006.05.005] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2005] [Revised: 03/10/2006] [Accepted: 05/06/2006] [Indexed: 10/24/2022]
Abstract
In this study, intravenous glucose tolerance test (ivGTT) and insulin challenge test (ICT) were applied to evaluate the influence of electroacupuncture (EA) on insulin sensitivity in rats. Firstly, hypoglycemic activity was confirmed on normal Wistar rats (36+/-12%) and streptozotocin (STZ)-induced diabetic rats (13+/-8%) after 60 min of 15 Hz EA on bilateral Zusanli acupoints. The rats were divided into the experiment group (EG) and control group (CG) randomly. After fasting, plasma glucose and insulin levels were assayed in the normal Wistar rats undergoing ivGTT. Plasma glucose levels and hypoglycemic activity were also evaluated in the normal Wistar rats and STZ diabetic rats during ICT. As the data showed, EA improved the glucose tolerance from 15 to 90 min (p<0.005 compared with the plasma glucose levels of the CG) during ivGTT. In addition, significant improvement in the Homeostasis Model Assessment (HOMA) index was found in the EG from 15 to 90 min (p<0.005 compared with the CG). More hypoglycemic activity was achieved in normal Wistar and STZ diabetic rats in the EG than in the CG (from 30 to 60 min) during ICT. In conclusion, the results suggest that 15 Hz EA at bilateral Zusanli acupoints improved glucose tolerance. Thus, EA should be considered as an alternative method for improving insulin sensitivity and/or increase insulin-hypoglycemic activity in rats.
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Affiliation(s)
- Shih-Liang Chang
- Graduate Institute of Integration of Chinese and Western Medicine, China Medical University, Taichung City, Taiwan, ROC.
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Chang SP, Chen YH, Chang WC, Liu IM, Cheng JT. Increase of adiponectin receptor gene expression by physical exercise in soleus muscle of obese Zucker rats. Eur J Appl Physiol 2006; 97:189-95. [PMID: 16568339 DOI: 10.1007/s00421-006-0163-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/08/2006] [Indexed: 10/24/2022]
Abstract
Aerobic exercise, including treadmill running has been widely used to treat insulin resistance and type 2 diabetes. We studied the effects of endurance training on gene expression of adiponectin receptor 1 (AdipoR1) in skeletal muscle of obese Zucker rats: the 8-week moderate exercise program consisted of treadmill running at 20 m/min and 0 degrees gradient for 1 h/day, 7 days/week. After 8 weeks, insulin action on glucose disposal rate was measured by glucose-insulin index, the product of the areas under the curve of glucose and insulin during intraperitoneal glucose tolerance testing. In contrast to results for sedentary obese rats, exercise training decreased plasma levels of insulin and glucose as well as the glucose-insulin index in obese rats, indicating the merit of regular moderate exercise for improvement of insulin sensitivity in this insulin-resistant animal model. Also, diabetes-related reductions in mRNA and protein content of AdipoR1 in soleus muscle were observed in obese rats at baseline; they were markedly reversed after the 8-week exercise program. However, such exercise training did not alter plasma levels of insulin and glucose in lean Zucker rats. Also, AdipoR1 gene expression in soleus muscle was not changed by exercise in lean Zucker rats compared with the sedentary, lean littermates. These results suggest that long-term exercise training may reverse reduced AdipoR1 gene expression in soleus muscle and improve insulin sensitivity in the obese Zucker rats. Thus, an endurance exercise training is probably helpful clinically for obese individuals with insulin resistance.
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Affiliation(s)
- Shih-Pei Chang
- Department of Physical Education and Department of Medical Technology, Central Taiwan University of Science and Technology, 4060, Taichung City, Taiwan, ROC
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Cheng JT, Huang CC, Liu IM, Tzeng TF, Chang CJ. Novel mechanism for plasma glucose-lowering action of metformin in streptozotocin-induced diabetic rats. Diabetes 2006; 55:819-25. [PMID: 16505249 DOI: 10.2337/diabetes.55.03.06.db05-0934] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To better understand the insulin-independent plasma glucose-lowering action of metformin, we used streptozotocin (STZ)-induced diabetic rats to investigate the possible mechanisms. Oral intake of metformin decreased the plasma glucose of STZ-induced diabetic rats with a parallel increase of plasma beta-endorphin-like immunoreactivity (BER). Mediation of opioid mu-receptors in the action of metformin was identified by the blockade of receptors with antagonist in STZ-induced diabetic rats and the failure of action in opioid mu-receptor knockout diabetic mice. Release of BER from adrenal glands by metformin was characterized, using bilateral adrenalectomy and the release of BER from isolated adrenal medulla of STZ-induced diabetic rats. Repeated treatment with metformin in STZ-induced diabetic rats increased the mRNA and protein levels of GLUT-4 in soleus muscle that was blocked by naloxonazine. Reduction of the mRNA or protein levels of hepatic PEPCK was also impeded in the same group of STZ-induced diabetic rats. In conclusion, our results provide novel mechanisms for the plasma glucose-lowering action of metformin, via an increase of beta-endorphin secretion from adrenal glands to stimulate opioid mu-receptor linkage, leading to an increase of GLUT-4 gene expression and an attenuation of hepatic PEPCK gene expression in STZ-induced diabetic rats.
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Affiliation(s)
- Juei-Tang Cheng
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan City, Taiwan 70101, ROC.
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