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Karbaschi R, Zardooz H. Pancreatic GLUT2 protein expression and isolated islets insulin secretion decreased in high-fat fed rat dams. J Diabetes Metab Disord 2023; 22:1511-1518. [PMID: 37975089 PMCID: PMC10638334 DOI: 10.1007/s40200-023-01274-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Accepted: 07/30/2023] [Indexed: 11/19/2023]
Abstract
Purpose Chronic consumption of high-fat foods during the reproductive period may endanger the dams' metabolic homeostasis and might adversely affect pregnancy outcome. In this regard the present study aimed to investigate the effect of long-term high-fat feeding on pancreatic glucose transporter-2 (GLUT2) protein expression and isolated islets glucose-stimulated insulin secretion in Wistar rat dams. Materials and methods Female rats were randomly divided into normal (N) and high-fat (HF; containing cow butter) diet groups and consumed their respective diets for 10 weeks (from prepregnancy to the end of lactation). After lactation, fasting plasma concentrations of glucose and insulin were measured to calculate HOMA-IR index, then intraperitoneal glucose tolerance test (IPGTT) was performed. Moreover, the pancreatic GLUT2 protein expression and insulin secretion from isolated islets at basal (5.6 mM) and stimulated (16.7 mM) glucose concentrations were assessed. Results In HF group compared to N group, the plasma insulin level increased, whereas the plasma glucose level did not change in fasting state. Accordingly, the HOMA-IR index increased in HF fed animals. Furthermore, the IPGTT revealed glucose intolerance based on the plasma glucose and insulin results. Also, the pancreatic GLUT2 expression and isolated islets insulin secretion, in response to high glucose concentration, were decreased. Conclusion The chronic consumption of high-fat foods during prepregnancy, pregnancy, and lactation periods can lead to glucose intolerance, insulin resistance, and inhibition of pancreatic GLUT2 expression, which impairs glucose homeostasis. Therefore, it is crucial to carefully monitor the diet composition of dams during this critical period. Supplementary Information The online version contains supplementary material available at 10.1007/s40200-023-01274-6.
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Affiliation(s)
- Roxana Karbaschi
- Faculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Homeira Zardooz
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Mechanistic Investigation of GHS-R Mediated Glucose-Stimulated Insulin Secretion in Pancreatic Islets. Biomolecules 2022; 12:biom12030407. [PMID: 35327599 PMCID: PMC8945998 DOI: 10.3390/biom12030407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/19/2022] [Accepted: 02/27/2022] [Indexed: 02/07/2023] Open
Abstract
Ghrelin receptor, a growth hormone secretagogue receptor (GHS-R), is expressed in the pancreas. Emerging evidence indicates that GHS-R is involved in the regulation of glucose-stimulated insulin secretion (GSIS), but the mechanism by which GHS-R regulates GSIS in the pancreas is unclear. In this study, we investigated the role of GHS-R on GSIS in detail using global Ghsr−/− mice (in vivo) and Ghsr-ablated pancreatic islets (ex vivo). GSIS was attenuated in both Ghsr−/− mice and Ghsr-ablated islets, while the islet morphology was similar between WT and Ghsr−/− mice. To elucidate the mechanism underpinning Ghsr-mediated GSIS, we investigated the key steps of the GSIS signaling cascade. The gene expression of glucose transporter 2 (Glut2) and the glucose-metabolic intermediate—glucose-6-phosphate (G6P) were reduced in Ghsr-ablated islets, supporting decreased glucose uptake. There was no difference in mitochondrial DNA content in the islets of WT and Ghsr−/− mice, but the ATP/ADP ratio in Ghsr−/− islets was significantly lower than that of WT islets. Moreover, the expression of pancreatic and duodenal homeobox 1 (Pdx1), as well as insulin signaling genes of insulin receptor (IR) and insulin receptor substrates 1 and 2 (IRS1/IRS2), was downregulated in Ghsr−/− islets. Akt is the key mediator of the insulin signaling cascade. Concurrently, Akt phosphorylation was reduced in the pancreas of Ghsr−/− mice under both insulin-stimulated and homeostatic conditions. These findings demonstrate that GHS-R ablation affects key components of the insulin signaling pathway in the pancreas, suggesting the existence of a cross-talk between GHS-R and the insulin signaling pathway in pancreatic islets, and GHS-R likely regulates GSIS via the Akt-Pdx1-GLUT2 pathway.
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Ugwu PI, Ben-Azu B, Ugwu SU, Uruaka CI, Nworgu CC, Okorie PO, Okafor KO, Anachuna KK, Elendu MU, Ugwu AO, Anyaehie UB, Nwankwo AA, Osim EE. Putative mechanisms involved in the psychopathologies of mice passively coping with psychosocial defeat stress by quercetin. Brain Res Bull 2022; 183:127-141. [DOI: 10.1016/j.brainresbull.2022.03.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 02/15/2022] [Accepted: 03/07/2022] [Indexed: 12/14/2022]
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Investigation of the effects of maternal separation on the pancreatic oxidative and inflammatory damages along with metabolic impairment in response to chronic social defeat stress in young adult male rats. J Diabetes Metab Disord 2021; 20:1557-1565. [PMID: 34900807 DOI: 10.1007/s40200-021-00902-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 09/13/2021] [Indexed: 10/20/2022]
Abstract
Purpose Chronic glucocorticoid release during the stress response has been proposed to initiate certain damages, which in turn produce metabolic disorders. The present study is the first work to test whether maternal separation (MS) would impact the metabolic alterations associated with pancreatic oxidative and inflammatory damages under chronic exposure to social defeat stress (CSDS) in adulthood. Methods During the first 2 weeks of life, male Wistar rats were exposed to MS or left undisturbed with their mothers (Std). Starting on postnatal day 50, the animals of each group were either left undisturbed in the standard group housing (Con) or underwent CSDS for 3 weeks. Thus, there were 4 groups (n = 7/group): Std-Con, Ms-Con, Std-CSDS, MS-CSDS. Each animal was weighed and then decapitated so that we could collect trunk blood for assessment of fasting plasma corticosterone, insulin, glucose, lipid profile, and insulin resistance. Plasma and pancreatic catalase activity, reduced glutathione (GSH), malondialdehyde levels and pancreatic interleukin-1 beta (IL-1β) content were also measured. Results MS-CSDS animals showed elevated plasma corticosterone and insulin levels (P < 0.01) along with insulin resistance (P < 0.05). According to one-way ANOVA results, chronic exposure to early or adult life adversity decreased body weight (P < 0.0001), Catalase activity and GSH levels (P < 0.0001) and increased malondialdehyde level (P = 0.0006) in plasma. Pancreatic MDA and IL-1β contents elevated just in MS-CSDS rats (P < 0.05). Conclusion Maternal separation shapes vulnerability to develop corticosterone hypersecretion, insulin resistance, pancreatic oxidative, and inflammatory damages associated with chronic exposure to later social challenges, which could potentially trigger metabolic disorders. Supplementary Information The online version contains supplementary material available at 10.1007/s40200-021-00902-3.
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Sadeghimahalli F, Karbaschi R, Salimi M, Khodagholi F, Zardooz H. Pancreatic HB9 protein level is affected by early life stress in young adult rats: possible involvement of TNF-α and corticosterone. Arch Physiol Biochem 2021; 127:406-413. [PMID: 31368362 DOI: 10.1080/13813455.2019.1645699] [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: 02/27/2019] [Revised: 06/25/2019] [Accepted: 07/15/2019] [Indexed: 01/06/2023]
Abstract
This study examined foot shock stress effects, during weaning, on pancreatic HB9 protein expression in young adult male rats in the presence or absence of adulthood stress. The pups were divided into Control, Early life stress, Young adult stress, and Early + young adult stress groups. Plasma corticosterone, insulin, glucose, and TNF-α concentrations, and pancreatic HB9 protein expression were assessed. At 2 weeks of age, stress increased plasma corticosterone level. During young adulthood, plasma TNF-α and glucose concentrations increased, whereas plasma insulin and pancreatic HB9 protein levels decreased in Early life stress group. Whereas, Early + young adulthood stress group showed no change in the study parameters, except for plasma corticosterone and insulin concentrations. Overall, early life stress reduced pancreatic HB9 protein expression possibly by elevating plasma corticosterone and TNF-α levels in early life and adulthood, respectively. However, combined with adulthood stress, HB9 protein expression increased to the level of Control.
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Affiliation(s)
- Forouzan Sadeghimahalli
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Education Development Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Roxana Karbaschi
- Faculty of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mina Salimi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fariba Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- NeuroBiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Homeira Zardooz
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Zardooz H, Sadeghimahalli F, Khodagholi F. Early postnatal stress impairs insulin secretion in response to psychological stress in adult rats. J Endocrinol Invest 2021; 44:277-286. [PMID: 32458408 DOI: 10.1007/s40618-020-01291-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 05/03/2020] [Indexed: 12/13/2022]
Abstract
PURPOSE Adversity in early life can induce metabolic defects in exposure to stress in adulthood. Therefore, the exploration of involving mechanisms can be helpful in the treatment of metabolic disorders. So, the present study was conducted in terms of exploring the effects of interaction between early postnatal stress and young adulthood psychological stress on insulin secretion and pancreatic GLUT-2 levels in male rats. METHODS Footshock as a model of early life stress (at 2 weeks of age) and psychological stress induced by communication box as a model of young adulthood stress (at 8-10 weeks of age) were induced in male Wistar rats for five consecutive days (2 times/day). Blood samples were drawn to measure glucose, insulin, homeostatic model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell dysfunction (HOMA-B), before and after stress protocol in young adult rats. Corticosterone was measured on days 1 and 5 of stress induction. The day after the stress period, factors including glucose tolerance, TNF-alpha, isolated islets' insulin output and levels of pancreatic GLUT-2 protein via western blotting were determined. RESULTS The combination of early footshock exposure and psychological stress during adulthood did not affect plasma corticosterone, but increased plasma insulin, HOMA-IR, HOMA-B and TNF-alpha levels. Plasma TNF was not only increased by the combination of both stressors, but also after only E STR exposure. HOMA-IR was increased in both Psy STR and E + Psy-STR groups. Plasma glucose just increased in Psy STR group. The combination of these two life stressors further increased the in vitro insulin secretion from isolated islets in response to 16.7-mM glucose. The level of Glut2 was increased in Psy STR and decreased in both E STR and E + Psy STR groups. Finally, glucose tolerance was impaired and glucose-stimulated insulin secretion was increased in E + Psy STR group. CONCLUSIONS In conclusion, inducing stress in early life makes the organism more susceptible to metabolic defects in exposure to psychological stress later in life.
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Affiliation(s)
- H Zardooz
- Department of Physiology and Neurophysiology Research Center, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - F Sadeghimahalli
- Department of Physiology, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
- Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran.
| | - F Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Faheem NM, Ali TM. The counteracting effects of (-)-Epigallocatechin-3-Gallate on the immobilization stress-induced adverse reactions in rat pancreas. Cell Stress Chaperones 2021; 26:159-172. [PMID: 33000400 PMCID: PMC7736449 DOI: 10.1007/s12192-020-01165-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/07/2020] [Accepted: 09/15/2020] [Indexed: 02/04/2023] Open
Abstract
Many studies suggest that Epigallocatechin-3-Gallate (EGCG) has many protective effects. But little is known about its protective effects against chronic restraint stress-induced damage in rats. The aim was to demonstrate the potential protective effects of EGCG against harmful pancreatic damage to the immobilization stress in the rat model. Forty rats, 2 months old, were divided into four groups (n = 10): control group; EGCG group, rats received EGCG by gavage (100 mg/kg /day) for 30 days; stressed group, rats exposed to immobilization stress; and stressed with EGCG group, rats exposed to immobilization stress and received EGCG for 30 days. Glycemic status parameters, corticosterone, and inflammatory markers were investigated on the first day, 15th day, and the 30th day of the experiment. Pancreatic oxidative stress markers and cytokines were evaluated. Histological, immunohistological, and statistical studies were performed. On the 15th day, fasting blood glucose (FBG), fasting plasma insulin (FPI), homeostatic model assessment for insulin resistance (HOMA-IR), and fasting plasma corticosterone were significantly higher in the stressed group when compared with first and 30th day in the same group as well as when compared with control and stressed with EGCG groups. The stressed group revealed significantly higher pancreatic IL-1β, IL-6, TNF-α, MDA, and NO, serum amylase and serum lipase, and significantly lower GSH, SOD, and CAT when compared to control and stressed with EGCG groups. EGCG treatment attenuated the pancreatic stress-induced cellular degeneration, leucocytic infiltration, and cytoplasmic vacuolations; significantly decreased area percentage of collagen fibers; and significantly increased mean area percentage of insulin immunopositive cell as compared with stressed group. EGCG is a protective agent against immobilization stress because of its anti-diabetic, anti-inflammatory, and and anti-oxidative stress properties, as confirmed by biochemical and histological alterations.
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Affiliation(s)
- Nermeen Mohammed Faheem
- Department of Anatomy, Faculty of Medicine, Ain Shams University, Cairo, Egypt.
- Department of Physical Therapy, Faculty of Applied Medical Sciences, Taif University, Taif, 21944, Kingdom of Saudi Arabia.
| | - Tarek Mohamed Ali
- Department of Medical Physiology, Faculty of Medicine, Taif University, P. O. Box 11099, Taif, 21944, Saudi Arabia
- Department of Medical Physiology, Faculty of Medicine, Beni-Suef University, Beni-Suef, Egypt
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Abdel Hafez SMN, Allam FAFA, Elbassuoni E. Sex differences impact the pancreatic response to chronic immobilization stress in rats. Cell Stress Chaperones 2021; 26:199-215. [PMID: 32986228 PMCID: PMC7736456 DOI: 10.1007/s12192-020-01169-y] [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: 08/08/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 12/27/2022] Open
Abstract
Chronic stress has been related to multiple diseases. Inflammation is proposed strongly to link stress to stress-related diseases in different organs, such as small intestine, colon, and brain. However, stress cellular effect on the pancreatic tissue, especially the exocrine one, had received relatively little attention. This work aimed to evaluate the cellular effect of chronic immobilization stress on the pancreatic tissue function and structure along with evaluating the sex role in this type of pancreatic injury. Thirty rats were equally divided into 5 groups: control male, control female, stressed male, stressed female, and stressed female with bilateral ovariectomy. Stressed rats were exposed to immobilization for 1 h/day, 6 days/week, for 3 weeks. Rats were then decapitated for further biochemical, histological, histo-morphometric, and immunohistochemical study. The results showed that, in male and female rats, chronic immobilization stress produced hypoinsulinemia and hyperglycemia, with increasing exocrine pancreatic injury markers by increasing oxidative and inflammatory status of the pancreatic tissue, and exhibited a degenerative effect on the pancreatic tissue. However, the stress-induced pancreatic effects were more obvious in male rats and female rats with bilateral ovariectomy than that in female rats. It could be concluded that male animals were more susceptible to stress-induced pancreatic damage than females. The ovarian hormones are responsible, at least partly, for pancreatic tissue protection since the stress-induced pancreatic injury in females was exacerbated by ovariectomy. In this study, inflammatory and oxidative stress differences in both sexes could provide a plausible explanation for sex differences.
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Affiliation(s)
| | | | - Eman Elbassuoni
- Physiology Department, Faculty of Medicine, Minia University, Minia, Egypt
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Salimi M, Sadeghimahalli F, Shaerzadeh F, Khodagholi F, Zardooz H. Early-life stress altered pancreatic Krebs cycle-related enzyme activities in response to young adulthood physical and psychological stress in male rat offspring. Horm Mol Biol Clin Investig 2020; 42:19-27. [PMID: 33781007 DOI: 10.1515/hmbci-2020-0063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/14/2020] [Indexed: 01/06/2023]
Abstract
OBJECTIVES Early-life stress (ELS) increases the risk of metabolic disorders in later life. The present study investigated the ELS effect on pancreatic pyruvate dehydrogenase (PDH) protein level, α-ketoglutarate dehydrogenase (α-KGDH), and aconitase activities as metabolic enzymes in response to young adulthood stress in male rat offspring. METHODS Male Wistar rats were divided into six groups: Control, early life stress (Early STR), young adult foot-shock stress (Y. adult F-SH STR), early + young adult foot-shock stress (Early + Y. adult F-SH STR), young adult psychological stress (Y. adult Psy STR) and early + young adult psychological stress (Early + Y. adult Psy STR). Stress was induced by a communication box at 2 weeks of age and young adulthood for five consecutive days. The blood samples were collected in young adult rats, then pancreases were removed to measure its PDH protein level and aconitase and α-KGDH activities. RESULTS In ELS animals, applying foot-shock stress in young adulthood increased PDH protein level, decreased α-KGDH and aconitase activities, and increased plasma glucose, insulin, and corticosterone concentrations. However, exposure to young adulthood psychological stress only decreased α-KGDH and aconitase activities. CONCLUSIONS It seems that ELS altered metabolic response to young adulthood stress through changes of Krebs cycle-related enzymes activities, though the type of adulthood stress was determinant.
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Affiliation(s)
- Mina Salimi
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Forouzan Sadeghimahalli
- Department of Physiology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Fatemeh Shaerzadeh
- Department of Neuroscience, University of Florida, Gainesville, Florida, USA
| | - Fariba Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Homeira Zardooz
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Celik-Tekeli M, Celebi N, Tekeli MY, Aktas Y. Evaluation of the hypoglycemic effect of exendin-4's new oral self-nanoemulsifying system in rats. Eur J Pharm Sci 2020; 158:105644. [PMID: 33197556 DOI: 10.1016/j.ejps.2020.105644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 10/27/2020] [Accepted: 11/06/2020] [Indexed: 01/24/2023]
Abstract
The objective of this study is to develop a new self-nanoemulsifying system containing exendin-4 with or without enzyme inhibitor chymostatin and to evaluate the effects of oral administration of exendin-4 and exendin-4/chymostatin loaded self nanoemulsifying system on plasma exendin-4, plasma insulin, blood glucose levels and to compare with the oral and subcutaneous administration of exendin-4 in non-diabetic and streptozotocin-induced type 2 diabetic rats. Exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying system containing ethyl oleate as the oil phase, Cremophor EL®/Labrasol® as the surfactants and propylene glycol as the co-solvent were prepared. The mean droplet size, polydispersity index, zeta potential and viscosity of exendin-4 loaded self-nanoemulsifying system were found as 24.28 ± 0.43 nm, 0.17 ± 0.01, -1.28 ± 3.61 mV, 79.60 ± 3.30 m.Pas, respectively. The mean droplet size, polydispersity index, zeta potential and viscosity of exendin-4/chymostatin loaded self-nanoemulsifying system were found as 20.25 ± 0.35 nm, 0.11 ± 0.02, -1.85 ± 2.49 mV, 100.02 ± 7.65 m.Pas, respectively according to our previous study. In the present study, we focused on long-term physical stability studies, pharmacokinetic studies and pharmacodynamic studies of prepared self-nanoemulsifying systems. According to the long- term physical stability data, exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying systems were found stable both at 5°C ± 3°C and at 25°C ± 60% RH for 12 months. Exendin-4 and exendin-4/chymostatin loaded self-nanoemulsifying systems increased AUC and Cmax values in non-diabetic rats compared to the oral exendin-4 solution. In diabetic rats, exendin-4/chymostatin loaded self nanoemulsifying systems increased Cmax values compared to the exendin-4 solution. Exendin-4/chymostatin loaded self-nanoemulsifying system decreased inter-subject variability compared to commercial Byetta®. At 30th minute after administration of exendin-4 loaded self-nanoemulsifying system, exendin-4/chymostatin loaded self nanoemulsifying system and Byetta®, blood glucose levels decreased to 23%, 25%, 29%, respectively. It has been shown that pharmacodynamic response is close to Byetta® with exendin-4/chymostatin self-nanoemulsifying system oral administration. In conclusion, a self nanoemulsifying system was found to be a suitable carrier system, and the combination with enzyme inhibitor chymostatin is thought to be promising for oral delivery of exendin-4.
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Affiliation(s)
- Merve Celik-Tekeli
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, 06330 Ankara, Turkey; Department of Pharmaceutical Technology, Erciyes University Faculty of Pharmacy, 38238 Kayseri, Turkey
| | - Nevin Celebi
- Department of Pharmaceutical Technology, Gazi University Faculty of Pharmacy, 06330 Ankara, Turkey; Department of Pharmaceutical Technology, Baskent University Faculty of Pharmacy, 06790 Ankara, Turkey
| | - M Yasin Tekeli
- Department of Pharmacology and Toxicology, Erciyes University Faculty of Veterinary Medicine, 38238 Kayseri, Turkey
| | - Yesim Aktas
- Department of Pharmaceutical Technology, Erciyes University Faculty of Pharmacy, 38238 Kayseri, Turkey.
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Briffa JF, Hosseini SS, Tran M, Moritz KM, Cuffe JS, Wlodek ME. Maternal growth restriction and stress exposure in rats differentially alters expression of components of the placental glucocorticoid barrier and nutrient transporters. Placenta 2017; 59:30-38. [DOI: 10.1016/j.placenta.2017.09.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 08/23/2017] [Accepted: 09/12/2017] [Indexed: 12/30/2022]
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12
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Zymantiene J, Zelvyte R, Pampariene I, Aniuliene A, Juodziukyniene N, Kantautaite J, Oberauskas V. Effects of long-term construction noise on health of adult female Wistar rats. Pol J Vet Sci 2017; 20:155-165. [PMID: 28525342 DOI: 10.1515/pjvs-2017-0020] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The aim of this study was to investigate the influence of long-term building construction noise from refurbishment, which including vibration, on some physiological parameters and histopathological changes of organs of Wistar rats. Twenty 12 month old female rats were divided into two groups: rats group I (n = 10) were exposed to long-term construction noise and rats group II (n = 10) were kept under normal noise level. Study results revealed that long-term construction noise from building refurbishment has an influence on body weight, haematological and some serum biochemical parameters affects caecal microbiota, and causes histopathological changes in the organs of adult female Wistar rats. It was noticed that rats in group I exihibited significantly higher mean values for total protein, albumin and lower values for glucose, AST, ALT, blood urea nitrogen, haematological and caecal microbiota parameters than rats in group II. The most common pathologies were determined in the kidney, liver and lungs. Other observed pathologies were lymphadenopathy, catarrhal inflammation of the intestines, spleen hyperplasia and mammary gland adenofibroma. Single cases were subcutaneous fibroma in the thoracic region, abortus with uterine inflammation and thymus hyperplasia with formation of cysts were found.
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Karbaschi R, Zardooz H, Khodagholi F, Dargahi L, Salimi M, Rashidi F. Maternal high-fat diet intensifies the metabolic response to stress in male rat offspring. Nutr Metab (Lond) 2017; 14:20. [PMID: 28261314 PMCID: PMC5329934 DOI: 10.1186/s12986-017-0177-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 02/17/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mother's consumption of high-fat food can affect glucose metabolism and the hypothalamic-pituitary-adrenal axis responsiveness in the offspring and potentially affect the metabolic responses to stress as well. This study examines the effect of maternal high-fat diet on the expression of pancreatic glucose transporter 2 and the secretion of insulin in response to stress in offspring. METHODS Female rats were randomly divided into normal and high-fat diet groups and were fed in accordance with their given diets from pre-pregnancy to the end of lactation. The offspring were divided into control (NC and HFC) and stress (NS and HFS) groups based on their mothers' diet and exposure to stress in adulthood. After the two-week stress induction period was over, an intraperitoneal glucose tolerance test (IPGTT) was performed and plasma glucose and insulin levels were assessed. The pancreas was then removed for measuring insulin secretion from the isolated islets as well as glucose transporter 2 mRNA expression and protein levels. RESULTS According to the results obtained, plasma corticosterone concentrations increased significantly on days 1 and 14 of the stress induction period and were lower on the last day compared to on the first day. In both the NS and HFS groups, stress reduced plasma insulin concentration in the IPGTT without changing the plasma glucose concentration, suggesting an increased insulin sensitivity in the NS and HFS groups, although more markedly in the latter. Stress reduced insulin secretion (at high glucose concentrations) and increased glucose transporter 2 mRNA and protein expression, especially in the HFS group. CONCLUSION Mothers' high-fat diet appears to intensify the stress response by changing the programming of the neuroendocrine system in the offspring.
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Affiliation(s)
- Roxana Karbaschi
- Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, 19615-1178 Tehran, Iran
| | - Homeira Zardooz
- Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, 19615-1178 Tehran, Iran
- Department of Physiology, School of Medicine, Shahid Beheshti University of Medical Sciences, 19615-1178 Tehran, Iran
| | - Fariba Khodagholi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Leila Dargahi
- NeuroBiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mina Salimi
- Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, 19615-1178 Tehran, Iran
| | - FatemehSadat Rashidi
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Animal Model of Gestational Diabetes Mellitus with Pathophysiological Resemblance to the Human Condition Induced by Multiple Factors (Nutritional, Pharmacological, and Stress) in Rats. BIOMED RESEARCH INTERNATIONAL 2016; 2016:9704607. [PMID: 27379252 PMCID: PMC4917720 DOI: 10.1155/2016/9704607] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 05/08/2016] [Indexed: 01/31/2023]
Abstract
This study attempts to develop an experimental gestational diabetes mellitus (GDM) animal model in female Sprague-Dawley rats. Rats were fed with high fat sucrose diet, impregnated, and induced with Streptozotocin and Nicotinamide on gestational day 0 (D0). Sleeping patterns of the rats were also manipulated to induce stress, a lifestyle factor that contributes to GDM. Rats were tested for glycemic parameters (glucose, C-peptide, and insulin), lipid profiles (total cholesterol, triglycerides, HDL, and LDL), genes affecting insulin signaling (IRS-2, AKT-1, and PCK-1), glucose transporters (GLUT-2 and GLUT-4), proinflammatory cytokines (IL-6, TNF-α), and antioxidants (SOD, CAT, and GPX) on D6 and D21. GDM rats showed possible insulin resistance as evidenced by high expression of proinflammatory cytokines, PCK-1 and CRP. Furthermore, low levels of IRS-2 and AKT-1 genes and downregulation of GLUT-4 from the initial to final phases indicate possible defect of insulin signaling. GDM rats also showed an impairment of antioxidant status and a hyperlipidemic state. Additionally, GDM rats exhibited significantly higher body weight and blood glucose and lower plasma insulin level and C-peptide than control. Based on the findings outlined, the current GDM animal model closely replicates the disease state in human and can serve as a reference for future investigations.
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Templeman NM, Mehran AE, Johnson JD. Hyper-Variability in Circulating Insulin, High Fat Feeding Outcomes, and Effects of Reducing Ins2 Dosage in Male Ins1-Null Mice in a Specific Pathogen-Free Facility. PLoS One 2016; 11:e0153280. [PMID: 27055260 PMCID: PMC4824531 DOI: 10.1371/journal.pone.0153280] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 03/25/2016] [Indexed: 12/31/2022] Open
Abstract
Insulin is an essential hormone with key roles in energy homeostasis and body composition. Mice and rats, unlike other mammals, have two insulin genes: the rodent-specific Ins1 gene and the ancestral Ins2 gene. The relationships between insulin gene dosage and obesity has previously been explored in male and female Ins2-/- mice with full or reduced Ins1 dosage, as well as in female Ins1-/- mice with full or partial Ins2 dosage. We report herein unexpected hyper-variability in Ins1-null male mice, with respect to their circulating insulin levels and to the physiological effects of modulating Ins2 gene dosage. Two large cohorts of Ins1-/-:Ins2+/- mice and their Ins1-/-:Ins2+/+ littermates were fed chow diet or high fat diet (HFD) from weaning, and housed in specific pathogen-free conditions. Cohort A and cohort B were studied one year apart. Contrary to female mice from the same litters, inactivating one Ins2 allele on the complete Ins1-null background did not consistently cause a reduction of circulating insulin in male mice, on either diet. In cohort A, all HFD-fed males showed an equivalent degree of insulin hypersecretion and weight gain, regardless of Ins2 dosage. In cohort B the effects of HFD appeared generally diminished, and cohort B Ins1-/-:Ins2+/- males showed decreased insulin levels and body mass compared to Ins1-/-:Ins2+/+ littermates, on both diets. Although experimental conditions were consistent between cohorts, we found that HFD-fed Ins1-/-:Ins2+/- mice with lower insulin levels had increased corticosterone. Collectively, these observations highlight the phenotypic characteristics that change in association with differences in circulating insulin and Ins2 gene dosage, particularly in male mice.
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Affiliation(s)
- Nicole M Templeman
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Arya E Mehran
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - James D Johnson
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Sadeghimahalli F, Karbaschi R, Zardooz H, Khodagholi F, Rostamkhani F. Effect of early life stress on pancreatic isolated islets' insulin secretion in young adult male rats subjected to chronic stress. Endocrine 2015; 48:493-503. [PMID: 25030548 DOI: 10.1007/s12020-014-0337-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 06/10/2014] [Indexed: 01/12/2023]
Abstract
Early stressful experiences may predispose organisms to certain disorders, including those of metabolic defects. This study aimed to explore the effects of early life stress on pancreatic insulin secretion and glucose transporter 2 (GLUT2) protein levels in stressed young adult male rats. Foot shock stress was induced in early life (at 2 weeks of age) and/or in young adulthood (at 8-10 weeks of age) for five consecutive days. Blood samples were taken before and after stress exposure in young adult rats. At the end of the experiment, glucose tolerance, isolated islets' insulin secretion, and pancreatic amounts of GLUT2 protein were measured. Our results show that early life stress has no effect on basal plasma corticosterone levels and adrenal weight, either alone or combined with young adulthood stress, but that early life + young adulthood stress could prevent weight gain, and cause an increase in basal plasma glucose and insulin. The homeostasis model assessment of insulin resistance index did not increase, when the rats were subjected to early life stress alone, but increased when combined with young adulthood stress. Moreover, glucose tolerance was impaired by the combination of early life + young adult stress. There was a decrease in islet's insulin secretion in rats subjected to early life stress in response to 5.6 mM glucose concentration, but an increase with a concentration of 16.7 mM glucose. However, in rats subjected to early life + young adulthood stress, islet's insulin secretion increased in response to both the levels of glucose concentrations. GLUT2 protein levels decreased in response to early life stress and early life + young adulthood stress, but there was a greater decrease in the early life stress group. In conclusion, perhaps early life stress sensitizes the body to stressors later in life, making it more susceptible to metabolic syndrome only when the two are in combination.
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Affiliation(s)
- Forouzan Sadeghimahalli
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Ghalami J, Zardooz H, Rostamkhani F, Farrokhi B, Hedayati M. Glucose-stimulated insulin secretion: Effects of high-fat diet and acute stress. J Endocrinol Invest 2013; 36:835-42. [PMID: 23656740 DOI: 10.3275/8959] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND One of the major topics in modern societies is the study of relationships between diet, stress and incidence of metabolic disorders. AIM This study aimed to investigate possible impairment in glucose-stimulated insulin secretion induced by a high-fat (cow intra-abdominal fat) diet in response to acute stress. MATERIALS AND METHODS Male Wistar rats were divided into high-fat and normal diet groups and each group was further divided into stress and control subgroups. Stress was induced by a communication box. Plasma levels of glucose, insulin and corticosterone were measured in both diet groups. Glucose tolerance, homeostasis model assessment of insulin resistance (HOMA-IR) index, glucose-stimulated insulin secretion from isolated islets, food and energy intake as well as body weight were also evaluated. RESULTS In the normal diet group, physical stress increased plasma glucose concentrations. In both diet groups, plasma corticosterone levels increased after stress. HOMA-IR index decreased in high-fat fed rats. Food intake decreased while energy intake increased in the high-fat diet rats. Body weight in both diet groups increased in a similar manner. The high-fat diet did not affect insulin secretion; however, stress decreased insulin secretion from isolated islets of both diet groups. Only in the high fat diet group did physical stress increase insulin secretion at 16.7 mM glucose. CONCLUSIONS The cow intra-abdominal fat, did not affect either plasma glucose and insulin concentrations or glucose-induced insulin secretion. Interestingly, it seems that the high-fat diet enabled the islets of the physically stressed rats to secrete more insulin in response to high glucose concentrations.
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Affiliation(s)
- J Ghalami
- Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, 19615-1178 Tehran, Iran
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18
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Karbalaei N, Ghasemi A, Faraji F, Zahediasl S. Comparison of the effect of maternal hypothyroidism on carbohydrate metabolism in young and aged male offspring in rats. Scandinavian Journal of Clinical and Laboratory Investigation 2012. [DOI: 10.3109/00365513.2012.743164] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | - Asghar Ghasemi
- Endocrine Physiology Research Center
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences,
Tehran, Iran
| | - Farzaneh Faraji
- Endocrine Physiology Research Center
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences,
Tehran, Iran
| | - Saleh Zahediasl
- Endocrine Physiology Research Center
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences,
Tehran, Iran
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Feng Y, Qi R, Xu M, Shen Z, Li M. Dietary iron supplements may affect stress adaptation and aggravate stress hyperglycemia in a rat model of psychological stress. Nutrition 2012; 28:691-7. [DOI: 10.1016/j.nut.2011.09.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 08/06/2011] [Accepted: 09/18/2011] [Indexed: 11/16/2022]
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Bauer CM, Glassman LW, Cyr NE, Romero LM. Effects of predictable and unpredictable food restriction on the stress response in molting and non-molting European starlings (Sturnus vulgaris). Comp Biochem Physiol A Mol Integr Physiol 2011; 160:390-9. [DOI: 10.1016/j.cbpa.2011.07.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 07/11/2011] [Accepted: 07/11/2011] [Indexed: 11/16/2022]
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Halataei BAS, Khosravi M, Arbabian S, Sahraei H, Golmanesh L, Zardooz H, Jalili C, Ghoshooni H. Saffron (Crocus sativus) Aqueous Extract and its Constituent Crocin Reduces Stress-induced Anorexia in Mice. Phytother Res 2011; 25:1833-8. [DOI: 10.1002/ptr.3495] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Revised: 03/09/2011] [Accepted: 03/10/2011] [Indexed: 11/06/2022]
Affiliation(s)
- Bahar-al-Sadat Halataei
- Department of Biology; Faculty of Science; Islamic AZAD University, North Tehran Branch; Tehran; Iran
| | - Maryam Khosravi
- Department of Biology; Faculty of Science; Islamic AZAD University, North Tehran Branch; Tehran; Iran
| | - Sedigheh Arbabian
- Department of Biology; Faculty of Science; Islamic AZAD University, North Tehran Branch; Tehran; Iran
| | - Hedayat Sahraei
- Department of Physiology and Biophysics; Faculty of Medicine, and Applied Neuroscience Research Center; Baqiyatallah (a.s.) University of Medical Sciences; Tehran; Iran
| | - Leila Golmanesh
- Molecular Biology Research Center; Baqiyatallah (a.s.) University of Medical Sciences; Tehran; Iran
| | - Homeira Zardooz
- Department of Physiology; School of Medicine; Shahid Beheshti University of Medical Sciences; Tehran; Iran
| | - Cyrus Jalili
- Department of Anatomy; School of Medicine; Kermanshah Medical University; Kermanshah; Iran
| | - Hassan Ghoshooni
- Department of Physiology and Biophysics; Faculty of Medicine, and Applied Neuroscience Research Center; Baqiyatallah (a.s.) University of Medical Sciences; Tehran; Iran
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Hjörleifsdottir-Steiner K, Satman I, Sundquist J, Kaya A, Wändell P. Diabetes and impaired glucose tolerance among Turkish immigrants in Sweden. Diabetes Res Clin Pract 2011; 92:118-23. [PMID: 21215486 DOI: 10.1016/j.diabres.2010.12.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2010] [Revised: 11/25/2010] [Accepted: 12/06/2010] [Indexed: 12/21/2022]
Abstract
AIM To investigate whether the prevalence of diabetes and impaired glucose tolerance (IGT) was higher among Turkish immigrants in Sweden, than in their area of origin in Turkey. METHODS 238 Turkish immigrants aged 20 years and older living in Flemingsberg, Sweden, were compared with 1549 participants of the same age living in the Konya area of Turkey. Data collection included anthropometric measurements, blood pressure (BP) measurements, and an oral glucose tolerance test (OGTT). RESULTS Prevalence of laboratory-verified diabetes was 11.8% among participants in Sweden compared to 7.1% among participants in Turkey (p 0.018). Turkish women in Sweden had a higher prevalence of diabetes than Turkish women in Turkey, 12.8% vs. 7.6% (p=0.037). Similarly, IGT was 17.8% among Turkish men in Sweden compared to 4.9% among men in Turkey (p<0.001) and 2-h blood glucose was higher among the immigrants (p<0.001). Systolic BP was also higher among the immigrants, especially in men (p<0.001) who also had a higher BMI (p=0.003). CONCLUSIONS The higher prevalence of diabetes and IGT among Turkish immigrants in Flemingsberg, Sweden, suggests that migration is associated with diabetes and that there are important implications for public health in Sweden.
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Mitra A, Crump EM, Alvers KM, Robertson KL, Rowland NE. Effect of high-fat diet on stress responsiveness in borderline hypertensive rats. Stress 2011; 14:42-52. [PMID: 20666663 DOI: 10.3109/10253890.2010.494746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Stress in combination with genetic susceptibility is a factor in the development of hypertension. We used borderline hypertensive rats to investigate whether exposure to high-fat and/or junk-food diet at different stages of ontogeny has programing consequences on stress responses. Wistar dams were fed a high- or low-fat diet for 6 weeks prior to mating with spontaneously hypertensive males, and during gestation. At birth, litters were fostered either to a dam in the same or an alternative diet condition as during gestation. After weaning, male offspring were fed either a control-chow diet or an intermittent junk food fatty diet. Between postnatal days 57-61, half of the rats in each dietary group received daily social defeat sessions using a resident-intruder protocol, and the other half were unstressed controls. Blood pressure was measured indirectly both before and after each defeat session. On the final day, rats were killed for physiological measures. Socially defeated rats showed large increases in serum corticosterone concentration and adrenal hypertrophy, indicating the effectiveness of this non-adapting stressor. Serum corticosterone level was also higher in rats fed with the junk-food diet post-weaning compared with those fed with chow only, but there were no significant effects of gestational or lactational dietary history.
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Affiliation(s)
- A Mitra
- Department of Psychology, University of Florida, Gainesville, FL, 32611-2250, USA.
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Effect of molecular mass of methoxypoly(ethylene glycol) activated with succinimidyl carbonate on camouflaging pancreatic islets. Biotechnol Appl Biochem 2010; 57:25-30. [DOI: 10.1042/ba20100145] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Cyr NE, Earle K, Tam C, Romero LM. The effect of chronic psychological stress on corticosterone, plasma metabolites, and immune responsiveness in European starlings. Gen Comp Endocrinol 2007; 154:59-66. [PMID: 17681504 DOI: 10.1016/j.ygcen.2007.06.016] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 05/08/2007] [Accepted: 06/20/2007] [Indexed: 11/21/2022]
Abstract
Although increases in glucocorticoid concentrations during acute stress are believed to help animals survive stressful events, chronic changes in glucocorticoid concentrations can alter metabolism and lead to disease. We studied the effect of chronic psychological stress on corticosterone (CORT), corticosterone binding globulin (CBG), glucose, and triglyceride concentrations as well as immune responsiveness to a T-cell mitogen challenge in European starlings, Sturnus vulgaris. To induce chronic stress we used a chronic stress protocol consisting of five stressors (loud radio, cage tapping, cage rolling, human voice, and bag restraint) administered in random order for 30 min for 4 times/day over 18 days. Total CORT decreased throughout the chronic stress period, which parallels a previous study with starlings. CBG capacity did not significantly change with chronic stress, thus free CORT followed the same pattern of attenuation as total CORT during chronic stress. Despite the change in regulation of CORT release, daytime glucose and triglyceride concentrations did not change with chronic stress. In addition, immune responsiveness in chronically stressed and unstressed birds was similar. Our results, together with a previous study using a similar CSP in European starlings, suggest that starlings physiologically dampen the HPA axis during chronic psychological stress to avoid pathology associated with chronically augmented CORT concentrations such as hyperglycemia and impaired immune function.
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Affiliation(s)
- Nicole E Cyr
- Department of Biology, Tufts University, Medford, MA 02155, USA.
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Hashimoto H, Moritani N, Katou M, Nishiya T, Kromkhun P, Yokosuka M, Tanaka M, Saito TR. Ontogenetic changes of ultrasonic vocalizations emitted from infant rats. Exp Anim 2007; 56:315-8. [PMID: 17660687 DOI: 10.1538/expanim.56.315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Ontogenetic changes of USVs were investigated to establish an index of stress in infant rats. The USVs were obtained by exposing infant rats to cold stress and were analyzed by real-time spectrography. USV waveforms consisted of four types, R-I, II, III and IV. These USVs were closely monitored at the age of 3-7 days in both sexes. From day 14, the frequency and incidence of USVs gradually decreased and had disappeared completely at the age of 21 days. Therefore, USVs should be useful in estimating the stress of infant rats between the ages of 3-7 days.
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Affiliation(s)
- Haruo Hashimoto
- Department of Comparative and Behavioral Medicine, Nippon Veterinary and Life Science University, Tokyo 180-8602, Japan
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