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Bavaresco A, Mazzeo P, Lazzara M, Barbot M. Adipose tissue in cortisol excess: What Cushing's syndrome can teach us? Biochem Pharmacol 2024; 223:116137. [PMID: 38494065 DOI: 10.1016/j.bcp.2024.116137] [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: 10/31/2023] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Endogenous Cushing's syndrome (CS) is a rare condition due to prolonged exposure to elevated circulating cortisol levels that features its typical phenotype characterised by moon face, proximal myopathy, easy bruising, hirsutism in females and a centripetal distribution of body fat. Given the direct and indirect effects of hypercortisolism, CS is a severe disease burdened by increased cardio-metabolic morbidity and mortality in which visceral adiposity plays a leading role. Although not commonly found in clinical setting, endogenous CS is definitely underestimated leading to delayed diagnosis with consequent increased rate of complications and reduced likelihood of their reversal after disease control. Most of all, CS is a unique model for systemic impairment induced by exogenous glucocorticoid therapy that is commonly prescribed for a number of chronic conditions in a relevant proportion of the worldwide population. In this review we aim to summarise on one side, the mechanisms behind visceral adiposity and lipid metabolism impairment in CS during active disease and after remission and on the other explore the potential role of cortisol in promoting adipose tissue accumulation.
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Affiliation(s)
- Alessandro Bavaresco
- Department of Medicine DIMED, University of Padua, Padua, Italy; Endocrinology Unit, Department of Medicine DIMED, University-Hospital of Padua, Padua, Italy
| | - Pierluigi Mazzeo
- Department of Medicine DIMED, University of Padua, Padua, Italy; Endocrinology Unit, Department of Medicine DIMED, University-Hospital of Padua, Padua, Italy
| | - Martina Lazzara
- Department of Medicine DIMED, University of Padua, Padua, Italy; Endocrinology Unit, Department of Medicine DIMED, University-Hospital of Padua, Padua, Italy
| | - Mattia Barbot
- Department of Medicine DIMED, University of Padua, Padua, Italy; Endocrinology Unit, Department of Medicine DIMED, University-Hospital of Padua, Padua, Italy.
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Rahimi L, Rajpal A, Ismail-Beigi F. Glucocorticoid-Induced Fatty Liver Disease. Diabetes Metab Syndr Obes 2020; 13:1133-1145. [PMID: 32368109 PMCID: PMC7171875 DOI: 10.2147/dmso.s247379] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/27/2020] [Indexed: 01/08/2023] Open
Abstract
Glucocorticoids (GCs) are commonly used at high doses and for prolonged periods (weeks to months) in the treatment of a variety of diseases. Among the many side effects are increased insulin resistance with disturbances in glucose/insulin homeostasis and increased deposition of lipids (mostly triglycerides) in the liver. Here, we review the metabolic pathways of lipid deposition and removal from the liver that become altered by excess glucocorticoids. Pathways of lipid deposition stimulated by excess glucocorticoids include 1) increase in appetite and high caloric intake; 2) increased blood glucose levels due to GC-induced stimulation of gluconeogenesis; 3) stimulation of de novo lipogenesis that is augmented by the high glucose and insulin levels and by GC itself; and 4) increased release of free fatty acids from adipose stores and stimulation of their uptake by the liver. Pathways that decrease hepatic lipids affected by glucocorticoids include a modest stimulation of very-low-density lipoprotein synthesis and secretion into the circulation and inhibition of β-oxidation of fatty acids. Role of 11β-hydroxysteroid dehydrogenases-1 and -2 and the reversible conversion of cortisol to cortisone on intracellular levels of cortisol is examined. In addition, GC control of osteocalcin expression and the effect of this bone-derived hormone in increasing insulin sensitivity are discussed. Finally, research focused on gaining a better understanding of the dose and duration of treatment with glucocorticoids, which leads to increased triglyceride deposition in the liver, and the reversibility of the condition is highlighted.
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Affiliation(s)
- Leili Rahimi
- Department of Medicine, Case Western Reserve University, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Aman Rajpal
- Department of Medicine, Case Western Reserve University, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Cleveland VA Medical Center, Cleveland, OH, USA
| | - Faramarz Ismail-Beigi
- Department of Medicine, Case Western Reserve University, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
- Cleveland VA Medical Center, Cleveland, OH, USA
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van den Beukel JC, Boon MR, Steenbergen J, Rensen PCN, Meijer OC, Themmen APN, Grefhorst A. Cold Exposure Partially Corrects Disturbances in Lipid Metabolism in a Male Mouse Model of Glucocorticoid Excess. Endocrinology 2015; 156:4115-28. [PMID: 26372178 DOI: 10.1210/en.2015-1092] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
High glucocorticoid concentrations are accompanied by metabolic side effects such as high plasma triglyceride (TG) concentrations. Liver, brown adipose tissue (BAT) and white adipose tissue are important regulators of plasma TG. Exposure to 4°C reduces plasma TG concentrations, and we therefore aimed to study the interaction between glucocorticoid excess and 24 hours of exposure to 4°C on lipid metabolism. For this, mice were implanted with 50-mg corticosterone or control pellets and housed for 24 hours at 23°C or 4°C 1 week later, after which various aspects of TG metabolism in liver, BAT, and white adipose tissue were studied. Corticosterone treatment resulted in a 3.8-fold increase of plasma TG concentrations. Increased TG was normalized by cold exposure, an effect still present 24 hours after cold exposure. Corticosterone treatment increased hepatic TG content by 3.5-fold and provoked secretion of large, TG-rich very low density lipoprotein particles. Cold exposure reduced very low density lipoprotein-TG secretion by approximately 50%. Corticosterone strongly decreased BAT activity: BAT weight increased by 3.5-fold, whereas uncoupling protein 1 (Ucp1) mRNA expression and Ucp1 protein content of BAT were reduced by 75% and 60%, respectively. Cold exposure partially normalized these parameters of BAT activity. The uptake of TG by BAT was not affected by corticosterone treatment but was increased 4.5-fold upon cold exposure. In conclusion, cold exposure normalizes corticosterone-induced hypertriglyceridemia, at least partly via activating BAT.
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Affiliation(s)
- Johanna C van den Beukel
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Mariëtte R Boon
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Jacobie Steenbergen
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Patrick C N Rensen
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Onno C Meijer
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Axel P N Themmen
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Aldo Grefhorst
- Department of Internal Medicine (J.C.v.d.B., J.S., A.P.N.T., A.G.), Erasmus University Medical Center, 3000 CA Rotterdam, The Netherlands; Department of Medicine (M.R.B., P.C.N.R., O.C.M.), Division of Endocrinology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands; and Einthoven Laboratory of Experimental Vascular Medicine (M.R.B., P.C.N.R., O.C.M.), Leiden University Medical Center, 2300 RC Leiden, The Netherlands
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Ross IL, Bergthorsdottir R, Levitt N, Dave JA, Schatz D, Marais D, Johannsson G. Cardiovascular risk factors in patients with Addison's disease: a comparative study of South African and Swedish patients. PLoS One 2014; 9:e90768. [PMID: 24603607 PMCID: PMC3948337 DOI: 10.1371/journal.pone.0090768] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Accepted: 02/04/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Patients with Addison's disease (AD) in Scandinavia have an increased risk for premature death due to cardiovascular disease (CVD). Serum lipids are important risk factors for CVD and vascular mortality. Replacement doses of hydrocortisone have historically been higher in Sweden than South Africa. The primary aim was to study the lipid profiles in a large group of patients with AD with the hypothesis that the lipid profile in patients in Sweden would be worse than in South Africa. METHODS In a cross-sectional study, 110 patients with AD (55 from South Africa, 55 from Sweden) matched for age, gender, ethnicity and BMI were studied. Anthropometric measures, blood pressure, lipids, highly sensitive C-reactive protein (hs-CRP) and adiponectin were studied. RESULTS All patients were Caucasian and the majority were women N = 36 (65.5%). Mean (standard deviation; SD) ages of the Swedish and South African patients were 52.9 (13.0) and 52.6 (14.4) years and BMI 25.3 (3.2) and 25.8 (4.1) kg/m2, respectively. The mean total daily hydrocortisone dose was greater in the Swedish patients than the South African patients, [33.0 (8.1) versus 24.3 (8.0) mg; p<0.0001]. South African patients had higher median (interquartilerange; IQR) triglycerides (TG) [1.59 (1.1-2.46) versus 0.96 (0.74-1.6) mmol/l; p<0.001], total cholesterol (TC) [6.02(1.50) versus 5.13 (0.87) mmol/l; p<0.001], LDL-C [4.43 (1.44) versus 2.75 (0.80) mmol/l; p<0.001] and median hs-CRP [2.15 (0.93-5.45) versus 0.99 (0.57-2.10) mg/L; p<0.003] and lower HDL-C [0.80 (0.40) versus 1.86 (0.46) mmol/l; p<0.001] than the Swedish patients. Approximately 20% of the patients in both cohorts had hypertension and diabetes mellitus. CONCLUSIONS South African patients with AD have worse lipid profiles and higher hs-CRP compared to their matched Swedish patients, despite lower doses of hydrocortisone. It is uncertain at this time whether these are due to genetic or environmental factors.
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Affiliation(s)
- Ian Louis Ross
- Division of Endocrinology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Ragnhildur Bergthorsdottir
- Department of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, Sweden
| | - Naomi Levitt
- Division of Endocrinology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Joel Alex Dave
- Division of Endocrinology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Desmond Schatz
- Department of Paediatrics, University of Florida, Gainesville, Florida, United States of America
| | - David Marais
- Division of Chemical Pathology, Clinical Laboratory Sciences, National Health Laboratory Service, University of Cape Town, Cape Town, South Africa
| | - Gudmundur Johannsson
- Department of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital, University of Gothenburg, Gothenburg, Sweden
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Ross IL, Levitt NS, Van der Merwe L, Schatz DA, Johannsson G, Dandara C, Pillay TS, Blom DJ. Investigation of glucocorticoid receptor polymorphisms in relation to metabolic parameters in Addison's disease. Eur J Endocrinol 2013; 168:403-12. [PMID: 23239757 DOI: 10.1530/eje-12-0808] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Uncertainty exists whether glucocorticoid receptor (GCR) polymorphisms play a role in steroid-related side effects in Addison's disease (AD) patients on hydrocortisone. The polymorphisms Bcll and N363S appear to increase sensitivity to cortisol, while the ER22/23EK polymorphism has been associated with resistance to cortisol. METHOD One hundred and forty seven AD patients, and gender, and ethnicity-matched controls were recruited in South Africa. Three polymorphisms in the GCR were studied, using PCR followed by restriction fragment length analysis. Associations with BMI, lipids, glucose and inflammatory markers were investigated. RESULTS In both patients and controls, the Bcll polymorphism occurred more frequently in whites than in other ethnic groups studied but was not associated with any of the metabolic parameters tested. The ER22/23EK polymorphism was associated with an increased BMI in both patients (29.4 vs 24.7 kg/m²) and control subjects (26.3 vs 24.2 kg/m²). The ER22/23EK polymorphism was also associated with lower LDL cholesterol in control subjects (3.46 vs 3.93 mmol/l) and in patients (3.52 vs 4.10 mmol/l). N363S was associated with increased BMI in controls 29.9 kg/m² vs wild type 24.8 kg/m². Median hydrocortisone doses were greater in patients heterozygous for either ER22/23EK 30.0 mg or N363S 25.0 mg polymorphisms than in wild type patients 20.0 mg (both comparisons). CONCLUSION Alterations in lipids, BMI and hydrocortisone dose were associated with two polymorphisms. Further larger studies are warranted to corroborate these findings.
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Affiliation(s)
- I L Ross
- Division of Endocrinology, Department of Medicine, Groote Schuur Hospital, University of Cape Town, J47 Old Main Building, Cape Town 7925, South Africa.
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Rodríguez-Sureda V, López-Tejero MD, Llobera M, Peinado-Onsurbe J. Social stress profoundly affects lipid metabolism: Over-expression of SR-BI in liver and changes in lipids and lipases in plasma and tissues of stressed mice. Atherosclerosis 2007; 195:57-65. [PMID: 17222414 DOI: 10.1016/j.atherosclerosis.2006.11.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Revised: 10/27/2006] [Accepted: 11/29/2006] [Indexed: 12/21/2022]
Abstract
We examined the effect of chronic social stress, similar to that endured by humans, on lipid metabolism of mice. The activity of the lipoprotein lipase (LPL) enzyme increased in adrenals, while in plasma it diminished significantly. Hepatic lipase (HL) was strongly affected in liver and adrenal glands, increasing four-fold and three-fold, respectively. At the same time, scavenger receptor class-B type-I (SR-BI), which are considered the high-density lipoprotein (HDL) receptor in the liver, increased significantly. Although the adrenals do not synthesise HL, the increase in HL may facilitate the uptake of HDL cholesterol for the synthesis of corticoids, which increase significantly following chronic stress. The volume of adrenal glands in control animals was significantly higher than in stressed animals (1.23+/-0.12 mm3 versus 0.29+/-0.06 mm3, p<0.001), corresponding with the weight difference of these organs. Medulla volume was also different in the two groups (0.27+/-0.10 mm3 versus 0.04+/-0.02 mm3, p<0.05). Despite this, corticosterone in plasma was significantly higher in stressed animals. Our results shows, for the first time, the effect of chronic social stress on lipid metabolism in general, and in particular on the SR-BI receptor and HL, which is directly involved in cholesterol reverse transport.
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Affiliation(s)
- Víctor Rodríguez-Sureda
- Departament de Bioquímica i Biologia Molecular, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, E-08028 Barcelona, Spain
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Berthiaume M, Laplante M, Festuccia WT, Cianflone K, Turcotte LP, Joanisse DR, Olivecrona G, Thieringer R, Deshaies Y. 11beta-HSD1 inhibition improves triglyceridemia through reduced liver VLDL secretion and partitions lipids toward oxidative tissues. Am J Physiol Endocrinol Metab 2007; 293:E1045-52. [PMID: 17666487 DOI: 10.1152/ajpendo.00276.2007] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Tissue-specific alterations in 11beta-hydroxysteroid dehydrogenase (HSD) type 1 activity, which amplifies glucocorticoid action, are thought to contribute to some of the metabolic complications of obesity. The present study tested whether hypertriglyceridemia is one such complication by investigating the effects of an 11beta-HSD1 inhibitor (compound A, 3 mgxkg(-1)xday(-1), 21 days) on triglyceride (TG) metabolism in a rat model of diet-induced obesity. The dose of compound A used did not affect food intake or final body weight. Compound A improved fasting triglyceridemia (-42%) through a robust reduction (-41%) in hepatic TG secretion rate, without change in plasma TG clearance rate. Uptake of TG-derived fatty acids was, however, increased in oxidative tissues, including red gastrocnemius (+47%), heart (+39%), and brown adipose tissue (BAT, +46%) at the expense of the liver, with a concomitant increase in plasma membrane fatty acid-binding protein. Lipid oxidation products were increased in red gastrocnemius (+35%) and heart (+33%), as were levels of uncoupling protein 1 mRNA in BAT (+48%), and carnitine palmitoyltransferase 1 activity tended to be increased in some oxidative tissues. These findings demonstrate that pharmacological inhibition of 11beta-HSD1 at a dose that does not affect food intake improves triglyceridemia by reducing hepatic very low density lipoprotein-TG secretion, with a shift in the pattern of TG-derived fatty acid uptake toward oxidative tissues, in which lipid accumulation is prevented by increased lipid oxidation.
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Affiliation(s)
- Magalie Berthiaume
- Faculty of Medicine, Laval Hospital Research Center, Laval Univ., 2725 Ch Sainte-Foy, QC, Canada G1V 4G5
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Berthiaume M, Laplante M, Tchernof A, Deshaies Y. Metabolic action of peroxisome proliferator-activated receptor γ agonism in rats with exogenous hypercorticosteronemia. Int J Obes (Lond) 2007; 31:1660-70. [PMID: 17579631 DOI: 10.1038/sj.ijo.0803668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The beneficial metabolic actions of peroxisome proliferator-activated receptor gamma (PPARgamma) agonism are associated with modifications in adipose tissue metabolism that include a reduction in local glucocorticoid (GC) production by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1). This study aimed to assess the contribution of GC attenuation to PPARgamma agonism action on gene expression in visceral adipose tissue and global metabolic profile. DESIGN Rats were treated (2 weeks) with the PPARgamma agonist rosiglitazone (RSG, 10 mg/kg/day) with concomitant infusion of vehicle (cholesterol implant) or corticosterone (HiCORT, 75 mg/implant/week) to defeat PPARgamma-mediated GC attenuation. MEASUREMENTS mRNA levels of enzymes involved in lipid uptake (and lipoprotein lipase activity), storage, lipolysis, recycling, and oxidation in retroperitoneal white adipose tissue (RWAT). Serum glucose, insulin and lipids, and lipid content of oxidative tissues. RESULTS Whereas HiCORT did not alter RWAT mass, RSG increased the latter (+33%) independently of the corticosterone status. Both HiCORT and RSG increased lipoprotein lipase activity, the mRNA levels of the de novo lipogenesis enzyme fatty acid synthase, and that of the fatty acid retention-promoting enzyme acyl-CoA synthase 1, albeit in a nonadditive fashion. Expression level of the lipolysis enzyme adipose triglyceride lipase was increased additively by HiCORT and RSG. PPARgamma agonism increased mRNA of the fatty acid recycling enzymes glycerol kinase and cytosolic phosphoenolpyruvate carboxykinase and those of the fatty acid oxidation enzymes muscle-type carnitine palmitoyltransferase 1 and acyl-CoA oxidase, whereas HiCORT remained without effect. HiCORT resulted in liver steatosis and hyperinsulinemia, which were abrogated by RSG, whereas the HiCORT-induced elevation in serum nonesterified fatty acid levels was only partially prevented. The hypotriglyceridemic action of RSG was maintained in HiCORT rats. CONCLUSION The GC and PPARgamma pathways exert both congruent and opposite actions on specific aspects of adipose tissue metabolism. Both the modulation of adipose gene expression and the beneficial global metabolic actions of PPARgamma agonism are retained under imposed high ambient GC, and are therefore independent from PPARgamma effects on 11beta-HSD1-mediated GC production.
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Affiliation(s)
- M Berthiaume
- Faculty of Medicine, Laval Hospital Research Center, Laval University, Québec, Québec, Canada
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Sato H, Miida T, Wada Y, Maruyama M, Murakami S, Hasegawa H, Kuroda T, Narita I, Nakano M, Gejyo F. Atherosclerosis is accelerated in patients with long-term well-controlled systemic lupus erythematosus (SLE). Clin Chim Acta 2007; 385:35-42. [PMID: 17644082 DOI: 10.1016/j.cca.2007.04.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2006] [Revised: 04/15/2007] [Accepted: 04/23/2007] [Indexed: 11/15/2022]
Abstract
BACKGROUND It is uncertain whether atherosclerosis is accelerated in premenopausal and postmenopausal patients with long-term well-controlled systemic lupus erythematosus (SLE). METHODS We measured the intima-media thickness (IMT) of the carotid arteries and the cardio-ankle vascular index (CAVI) in 39 women with SLE and in age- and sex-matched controls. RESULTS In the premenopausal state, carotid plaque was detected only in SLE patients (36%). In the postmenopausal state, the maximum IMT was about 2-fold greater in SLE patients than in control subjects (1.3+/-0.7 vs. 0.7+/-0.2 mm, p<0.001). CAVI was higher in both the premenopausal and postmenopausal SLE patients. The serum amyloid A protein (SAA) was higher in SLE patients in the premenopausal state (p=0.025), while remnant like particle-cholesterol (RLP-C), the homeostasis model assessment of insulin resistance (HOMA-IR), and SAA were significantly increased in postmenopausal SLE patients (p=0.001, p<0.001 and p<0.05, respectively). Multiple regression analysis revealed that the maximum IMT was associated with cumulative PSL dosage (p=0.027) and SAA (p=0.074) in the premenopausal SLE patients, and with HOMA-IR (p<0.001) in the postmenopausal SLE patients. CONCLUSION Atherosclerosis is accelerated in long-term well-controlled SLE. More attention should be given to subclinical inflammation and insulin resistance in the management of SLE patients.
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Affiliation(s)
- Hiroe Sato
- Niigata University Graduate School of Medical and Dental Sciences, Division of Nephrology and Rheumatology, 1-754 Asahimachi-Dori, Chuo-Ku Niigata, Niigata 951-8510, Japan
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Berthiaume M, Laplante M, Festuccia W, Gélinas Y, Poulin S, Lalonde J, Joanisse DR, Thieringer R, Deshaies Y. Depot-specific modulation of rat intraabdominal adipose tissue lipid metabolism by pharmacological inhibition of 11beta-hydroxysteroid dehydrogenase type 1. Endocrinology 2007; 148:2391-7. [PMID: 17272400 DOI: 10.1210/en.2006-1199] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The metabolic consequences of visceral obesity have been associated with amplification of glucocorticoid action by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) in adipose tissue. This study aimed to assess in a rat model of diet-induced obesity the effects of pharmacological 11beta-HSD1 inhibition on the morphology and expression of key genes of lipid metabolism in intraabdominal adipose depots. Rats fed a high-sucrose, high-fat diet were treated or not with a specific 11beta-HSD1 inhibitor (compound A, 3 mg/kg.d) for 3 wk. Compound A did not alter food intake or body weight gain but specifically reduced mesenteric adipose weight (-18%) and adipocyte size, without significantly affecting those of epididymal or retroperitoneal depots. In mesenteric fat, the inhibitor decreased (to 25-50% of control) mRNA levels of genes involved in lipid synthesis (FAS, SCD1, DGAT1) and fatty acid cycling (lipolysis/reesterification, ATGL and PEPCK) and increased (30%) the activity of the fatty acid oxidation-promoting enzyme carnitine palmitoyltransferase 1. In striking contrast, in the epididymal depot, 11beta-HSD1 inhibition increased (1.5-5-fold) mRNA levels of those genes related to lipid synthesis/cycling and slightly decreased carnitine palmitoyltransferase 1 activity, whereas gene expression remained unaffected in the retroperitoneal depot. Compound A robustly reduced liver triacylglycerol content and plasma lipids. The study demonstrates that pharmacological inhibition of 11beta-HSD1, at a dose that does not alter food intake, reduces fat accretion specifically in the mesenterical adipose depot, exerts divergent intraabdominal depot-specific effects on genes of lipid metabolism, and reduces steatosis and lipemia.
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Affiliation(s)
- Magalie Berthiaume
- Laval Hospital Research Center, Department of Anatomy and Physiology, Laval University, Quebec, Canada G1V 4G5
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Kozyreva T, Lomakina S, Tuzikov F, Tuzikova N. Plasma lipoproteins under the effect of cold exposure in normotensive and hypertensive rats. J Therm Biol 2004. [DOI: 10.1016/j.jtherbio.2003.09.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Abstract
This review article focuses on the ontogeny and the regulatory mechanisms involved in the modulation of the intracellular events governing the assembly and delivery of lipoproteins in human gut. The human fetal intestine organizes villi covered with well-differentiated enterocytes during the end of the first trimester in utero. One striking event is the formation of villi in the colonic mucosa similar to those of the small intestine. The small intestine exhibits very early (14-20 weeks) the capacity to absorb lipids, to elaborate most of the major lipoprotein classes (chylomicrons, very-low-density lipoproteins, low-density lipoproteins, high-density lipoproteins), and to efficiently export these lipoproteins from the intestinal cells. The ontogenic changes of lipid and lipoprotein synthesis are correlated with specific patterns of regulatory enzymes (HMG-CoA reductase, ACAT, MGAT) that are representative of key patterns such as the cholesterol pathway, cholesterol esterification, and neutral lipid pathway. The human fetal colon also has the capability to synthesize lipids, lipoproteins, and apolipoproteins. However, comapred with the small intestine, it is much less efficient at exporting these lipoproteins. Epidermal growth factor, insulin, and hydrocortisone, which are known modulators of the brush border digestive functions of the human gut, differentially modulate the synthesis and secretion of lipoproteins in the small intestine and colon. The use of human fetal gut represents a unique model to further our understanding of the complex biosynthetic molecular events essential for the formation and secretion of lipoproteins relevant to human intestine, both in normal or pathological conditions.
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Affiliation(s)
- E Levy
- Department of Nutrition, Centre de Recherche, Hôpital Ste-Justine, Université de Montréal, Québec, Canada H3T 1C5
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13
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Farombi EO, Akinloye O, Akinmoladun CO, Emerole GO. Hepatic drug metabolizing enzyme induction and serum triacylglycerol elevation in rats treated with chlordiazepoxide, griseofulvin, rifampicin and phenytoin. Clin Chim Acta 1999; 289:1-10. [PMID: 10556648 DOI: 10.1016/s0009-8981(99)00143-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Five days intraperitoneal administration of rats with chlordiazepoxide (0.4 mg/kg), griseofulvin (7 mg/kg), rifampicin (8. 6 mg/kg), phenytoin (4.3 mg/kg) and phenobarbitone (1.4 mg/kg; an established inducer of microsomal enzymes) caused a significant increase in serum triacylglycerol (P<0.001) and the activities of aniline hydroxylase, aminopyrine N-demethylase and p-nitroanisole O-demethylase (P<0.001). Aniline hydroxylase, aminopyrine N-demethylase and p-nitroanisole O-demethylase activities were increased 1.48-, 1.15- and 1.47-fold, respectively, in chlordiazepoxide-treated rats, 1.65-, 1.20- and 1.38-fold in griseofulvin-treated rats, 1.74-, 1.36- and 1.44-fold in rifampicin-treated rats, 1.56-, 1.29- and 1.62-fold in phenytoin-treated rats and 2.26-, 1.72- and 1.93-fold in phenobarbitone-treated rats. Chlordiazepoxide, griseofulvin, rifampicin, phenytoin and phenobarbitone increased the activity of cytosolic phosphatidate phosphohydrolase by 52, 58, 67, 73 and 82%, respectively, while the drugs elicited 50, 60, 60, 73 and 87% increases in the activity of the microsomal phosphatidate phosphohydrolase. Similarly, chlordiazepoxide, griseofulvin, rifampicin, phenytoin and phenobarbitone elicited 2.4-, 2.39-, 2.34-, 1.69- and 3.75-fold increases in serum triacylglycerol concentrations. The correlations between serum triacylglycerol concentrations and the activities of aniline hydroxylase, aminopyrine N-demethylase and p-nitroanisole O-demethylase were significant in all treatment groups (r=0.83, r=0.92 and r=0.87, respectively, n=30, P<0.001). Our results suggest that induction of hepatic enzymes by the administered drugs may lead to hypertriglyceridaemia as an adverse effect, possibly by inducing the activity of regulatory enzymes in the biosynthesis of triglyceride.
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Affiliation(s)
- E O Farombi
- Drug Metabolism and Toxicology Unit, Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria.
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15
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Mantha L, Palacios E, Deshaies Y. Modulation of triglyceride metabolism by glucocorticoids in diet-induced obesity. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:R455-64. [PMID: 10444552 DOI: 10.1152/ajpregu.1999.277.2.r455] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The involvement of glucocorticoids (GC) in the development of diet-induced obesity and in the concomitant adaptations of triglyceride (TG)-rich lipoprotein metabolism were examined. Rats were fed either rodent chow, which maintains a low lipid flux, or a diet high in sucrose and fat (HSF) that increases lipid flux, leading to metabolic perturbations similar to those that define the plurimetabolic syndrome in humans. The GC status was manipulated through adrenalectomy (ADX) and corticosterone (Cort) replacement. Compared with chow, the HSF diet increased energy intake (17%) and whole body (8%) and adipose tissue (80%) weights. The HSF diet also increased the acute postprandial rise in plasma insulin (4-fold) and TG (3-fold), fasting liver TG content (3-fold), triglyceridemia (54%), and adipose tissue lipoprotein lipase (LPL) activity (2-fold). ADX decreased energy intake and whole body and adipose tissue weights in both dietary cohorts, but more so in HSF-fed than in chow-fed animals. These ADX-induced effects were totally prevented by Cort replacement in rats fed chow, but only partially so in those fed the HSF diet in proportion to the degree of restoration of energy intake. In the chow-fed cohort, the above indexes of TG metabolism remained unaffected by the Cort status, whereas in the HSF-fed cohort, these variables were decreased by ADX to levels of chow-fed animals. Cort replacement in the HSF-fed animals restored indexes of TG metabolism to intact levels and reestablished the diet-related differences observed in intact animals. These findings indicate that GC modulate fasting TG metabolism only minimally when a diet that maintains a low lipid flux is fed. In contrast, their presence is a necessary condition for the development of diet-induced obesity and the concomitant alterations in insulin sensitivity and TG-rich lipoprotein metabolism.
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Affiliation(s)
- L Mantha
- Center for Research on Energy Metabolism and Department of Physiology, School of Medicine, Laval University, Quebec, Canada G1K 7P4
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16
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Belkebir-Mesbah D, Bonnefont-Rousselot D, Frey-Fressart V, Moinard C, Delattre J, Vasson MP. Consequences of treatment with dexamethasone in rats on the susceptibility of total plasma and isolated lipoprotein fractions to copper oxidation. Endocrine 1999; 10:233-42. [PMID: 10484287 DOI: 10.1007/bf02738622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
According to the oxidative hypothesis of atherosclerosis, a hyperoxidizability of lipoproteins could favor the development of the atherosclerotic process. Besides, it has been recently reported that models of elevated very-low-density-lipoprotein (VLDL) levels in rats resulted in an increased susceptibility of these VLDL to oxidation. Treatment with dexamethasone classically induces an increase in plasma VLDL concentration. The aim of our study was thus to assess the effects of a treatment with dexamethasone in rats on the susceptibility to copper oxidation, both on total plasma and on isolated lipoproteins. Male Sprague-Dawley rats aged three months were treated with a daily intraperitoneal injection of dexamethasone (1.5 mg per kg) for five days (DEX group), whereas control rats were fed ad libitum (AL group). In order to take into account the decrease of food intake induced by dexamethasone treatment, a group of pair-fed rats was constituted (PF group). These rats had the same food intake as rats of the DEX group and were treated with a daily isovolumic intraperitoneal injection of NaCl for 5 d. After 5 d treatment, rats were fasted overnight, then killed, and blood was collected on EDTA. Low-density lipoproteins (VLDL + LDL) and high-density lipoproteins (HDL) were isolated by ultracentrifugation. A copper oxidation was conducted both on total plasma and on isolated lipoproteins. As expected, after treatment with dexamethasone, plasma exhibited increased triglyceride and glucose levels. Similarly, VLDL + LDL of rats from the DEX group were enriched with triglycerides, when compared with VLDL + LDL of the other two groups of rats. Our major finding was a marked increase in the susceptibility of total plasma of the DEX group to copper oxidation, in comparison with the other two groups of rats. This oxidizability was assessed by the maximal level of oxidation products absorbing at 234 nm and classically considered to be conjugated dienes (7.46+/-0.70 micromol L(-1) in the DEX group vs. 3.36+/-0.40 and 2.05+/-0.60 micromol L(-1) in the AL and PF groups, respectively). Nevertheless, this higher oxidizability was not observed in the isolated lipoprotein fractions, as shown by the formation of lipid peroxidation products such as conjugated dienes, thiobarbituric-acid reactive substances, hydroperoxides, 7-ketocholesterol, and dienals. This is not in agreement with other models of hypertriglyceridemia that have been reported to induce a hyperoxidizability of lipoproteins in rats. Our results led us to hypothesize that other plasma components such as proteins could be involved in this susceptibility to oxidation. Indeed, the severe protein catabolism induced by dexamethasone treatment could support this hypothesis, by forming protein components that are more susceptible to oxidation, as shown by an increased carbonyl formation upon plasma copper oxidation.
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Affiliation(s)
- D Belkebir-Mesbah
- Laboratoire de Biochimie Métabolique et Clinique, Faculté des Sciences Pharmaceutiques et Biologiques, Université René Descartes Paris V, France
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17
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Ferraris JR, Sorroche P, Legal S, Oyhamburu J, Brandi P, Pasqualini T. Effect of therapy with deflazacort on dyslipoproteinemia after pediatric renal transplantation. J Pediatr 1998; 133:533-6. [PMID: 9787693 DOI: 10.1016/s0022-3476(98)70063-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Deflazacort is an oxazolone compound derived from prednisolone, with similar immunosuppressive action but fewer side effects. Kidney function, weight/height ratio, serum triglycerides, cholesterol, high-density lipoprotein (HDL) cholesterol, very-low-density lipoprotein cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein A, apolipoprotein B, and lipoprotein (a) were studied before and 6 months after substitution of deflazacort (mean +/- SEM, 0.3 +/- 0.1 mg/kg per day) for methylprednisone (0.2 +/- 0.1 mg/kg per day) in 14 patients treated with cyclosporine, aged 3.1 to 20.3 years, 3 years after renal transplantation. Serum creatinine and calculated creatinine clearance did not change significantly, and weight/height ratio decreased from 20.0% +/- 7.1% to 12.5% +/- 6.5% (P < .005) during deflazacort therapy. Total cholesterol was reduced by 15.9% (from 233 +/- 15 mg/dL to 196 +/- 13 mg/dL, P < .01), LDL cholesterol by 25.5% (from 153 +/- 14 mg/dL to 114 +/- 12 mg/dL, P < .01), and TC/HDL cholesterol ratio by 28.3% (from 5.3 +/- 0.4 to 3.8 +/- 0.4, P < .01), whereas HDL cholesterol increased 18% (from 45 +/- 2 mg/dL to 53 +/- 2 mg/dL) and apolipoprotein A by 8.3% (from 122 +/- 5 mg/dL to 132 +/- 5 mg/dL, P < .05) during deflazacort therapy. Our data suggest that substituting deflazacort for maintenance methylprednisone therapy leads to an improvement in the lipoprotein profile of children after renal transplantation.
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Affiliation(s)
- J R Ferraris
- Servicio de Nefrología Pediátrica, Hospital Italiano de Buenos Aires, Argentina
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18
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Augustine SM, Baumgartner WA, Kasper EK. Obesity and hypercholesterolemia following heart transplantation. JOURNAL OF TRANSPLANT COORDINATION : OFFICIAL PUBLICATION OF THE NORTH AMERICAN TRANSPLANT COORDINATORS ORGANIZATION (NATCO) 1998; 8:164-9. [PMID: 9866546 DOI: 10.7182/prtr.1.8.3.eg2p05773u818q54] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Successful strategies for avoiding obesity and hypercholesterolemia are difficult to validate because of imprecise problem identification. The purpose of this study was to describe the incidence, severity, and onset of obesity and hypercholesterolemia among heart transplant recipients and identify relationships between demographic variables and weight or cholesterol levels during the first year following transplantation. Data were collected from retrospective chart review. Forty-two patients were randomly selected from 224 patients who were undergoing heart transplantation at the Johns Hopkins Hospital between July 1983 and December 1995. Significant differences were found in weight and cholesterol level during the first 12 months. Patients with ideal body weight less than 110%, compared with greater than 110%, survived longer. Relationships were identified between prednisone dose and weight, cumulative prednisone dose and weight, and weight change and change in total cholesterol level 1 year following transplantation. Multivariate analysis showed cumulative prednisone as an independent predictor of weight. Obesity and hypercholesterolemia were significant problems within 3 months of transplantation. Although prednisone dosage should be adjusted to the lowest possible dose, dietary and lifestyle changes remain the foundation of effective management of these posttransplant complications.
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Affiliation(s)
- S M Augustine
- Division of Cardiac Surgery, Johns Hopkins Hospital, Baltimore, Md. 21286, USA
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19
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Latour MA, Laiche SA, Thompson JR, Pond AL, Peebles ED. Continuous infusion of adrenocorticotropin elevates circulating lipoprotein cholesterol and corticosterone concentrations in chickens. Poult Sci 1996; 75:1428-32. [PMID: 8933597 DOI: 10.3382/ps.0751428] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The purpose of the present study was to investigate the effects of elevated corticosterone (CORT) on circulating lipoprotein cholesterol during a 1-wk period. For this study, 15 commercial broilers were randomly assigned to one of three treatment groups. Group 1 served as the control (CON) and received no treatment, whereas Groups 2 and 3 received subcutaneous mini-osmotic pumps containing either physiological saline (PS) or adrenocorticotropin (ACTH), respectively. The ACTH was delivered at a rate of 8 IU/kg of BW/d. Blood samples were taken at Time 0 (before implants) and on Days 2, 4, and 7 postimplantation. Continuous infusion of ACTH increased plasma glucose, cholesterol, triglycerides, very low density lipoprotein cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and CORT during the postimplantation period. The group treated with ACTH also exhibited a decrease in BW during the last 2 sampling d. There were no differences in any of the serum constituents measured between CON and PS birds, which suggest that CON birds can serve as useful controls. These data suggest that birds given a continuous infusion of ACTH at 8 IU/kg of BW/d can experience changes in plasma lipoprotein cholesterol concentrations along with changes in other blood parameters and may serve as a useful model in accelerated lipoprotein production.
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Affiliation(s)
- M A Latour
- Poultry Science Department, Mississippi State University, Mississippi State 39762, USA
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20
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Kancha RK, Hussain MM. Up-regulation of the low density lipoprotein receptor-related protein by dexamethasone in HepG2 cells. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1301:213-20. [PMID: 8664331 DOI: 10.1016/0005-2760(96)00036-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Dexamethasone has been shown to decrease the expression of the low density lipoprotein (LDL) receptor, but its effect on other members of the LDL receptor family is not known. We studied the effect of dexamethasone in HepG2 cells on the expression of the LDL receptor family members using radiolabeled receptor associated protein (RAP) which binds to all the members of the family. Treatment of HepG2 cells with increasing concentrations of dexamethasone resulted in a 2-fold increase in the binding and degradation of RAP. To identify the receptor responsible for the increased binding and degradation of RAP, we used specific ligands. For LDL receptor, we used LDL itself. For the LDL receptor-related protein/alpha 2-macroglobulin receptor, we used activated alpha 2-macroglobulin. The binding of LDL to HepG2 cells was decreased, whereas binding and degradation of activated alpha 2-macroglobulin was increased by 2-fold suggesting that dexamethasone increased LRP expression. Increased LRP expression was positively correlated with the increase in the steady-state levels and transcript numbers of the LRP mRNA; no changes in RAP or gamma-actin mRNA levels were observed. Increased mRNA levels were not due to an increased rate of transcription of the gene as assessed by nuclear run-on experiments. These studies indicate that dexamethasone increases cell-surface LRP activity in HepG2 cells by increasing the steady state mRNA levels and suggest that post-transcriptional mechanisms play a role in controlling LRP mRNA levels.
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Affiliation(s)
- R K Kancha
- Department of Pathology, Medical College of Pennsylvania, Philadelphia, USA
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21
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Palacios E, Piñon-López MJ, Racotta IS, Racotta R. Effect of lipectomy and long-term dexamethasone on visceral fat and metabolic variables in rats. Metabolism 1995; 44:1631-8. [PMID: 8786735 DOI: 10.1016/0026-0495(95)90086-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Intraperitoneal (IP) fat accumulation in humans is a risk factor for a number of diseases. We tried to increase this particular adipose mass in rats by long-term administration of low-dose dexamethasone (Dex) and/or elimination of other fat depots. Male adult Wistar rats were lipectomized (Lip) or sham-operated (Sh). Bilateral lipectomy of retroperitoneal and inguinal fat pads was performed under anesthesia with Na pentobarbital 40 mg/kg supplemented with ether. After 8 days, half the animals of each group received Dex in their drinking water (0.1 microgram/mL) while the other half received water (W), for a total of four groups: Sh-W, Lip-W, Sh-Dex, and Lip-Dex. Body weight (BW) and food and water intake were measured throughout the treatment period. A glucose tolerance test was performed 34 days after starting Dex treatment, and then rats were killed, fat depots were weighed, and plasma and liver were obtained for metabolic determinations. Dex rats ate the same amount of food as W controls, but gained significantly less weight (2.02 +/- 0.18 v 3.82 +/- 0.10 g/d, P < .01). Mean daily W intake was approximately 40 mL/d in all groups, which means that Dex rats ingested approximately 4 micrograms/d Dex. Average glycemic values during the 180-minute glucose tolerance test were as follows: Sh-W, 162 +/- 13; Lip-W, 166 +/- 7; Sh-Dex, 118 +/- 6; and Lip-Dex, 229 +/- 27 mg/dL. These values show that glucose tolerance was improved by Dex treatment alone, but was impaired in Lip-Dex animals. The same trend was evident for the relative weights (percent of BW) of two intact adipose depots: IP and epididymal (EPI) (Sh-W, 2.08 +/- 0.13 and 1.35 +/- 0.11, respectively; Lip-W, 1.67 +/- 0.15 and 1.17 +/- 0.11; Sh-Dex, 1.66 +/- 0.10 and 1.28 +/- 0.07; Lip-Dex, 2.41 +/- 0.11 and 1.53 +/- 0.09). Average glycemia for all rats was significantly correlated with IP (r = .55, P < .01) but not with EPI; moreover it was correlated in the Sh-W control group (r = .81, P < .05), suggesting a normal relation between these variables. Liver triglycerides (LTG), which were elevated in Dex rats, were also correlated with IP (r = .51, P < .02 for all rats and r = .82, P < .05 for Sh-W rats). The results show that long-term administration of low-dose Dex has some different effects in normal versus Lip rats concerning mainly the IP fat depot, the relative mass of which seems to significantly affect glucose tolerance.
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Affiliation(s)
- E Palacios
- Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional (ICN), México Distrito Federal, Mexico
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22
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Wang CN, McLeod RS, Yao Z, Brindley DN. Effects of dexamethasone on the synthesis, degradation, and secretion of apolipoprotein B in cultured rat hepatocytes. Arterioscler Thromb Vasc Biol 1995; 15:1481-91. [PMID: 7670964 DOI: 10.1161/01.atv.15.9.1481] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Oversecretion of apoB and decreased removal of apoB-containing lipoproteins by the liver results in hyperapobetalipoproteinemia, which is a risk factor for atherosclerosis. We investigated how dexamethasone, a synthetic glucocorticoid, affects the synthesis, degradation, and secretion of apoB-100 and apoB-48. Primary rat hepatocytes were incubated with dexamethasone for 16 hours. Incorporation of [35S]methionine into apoB-48 and apoB-100 was increased by 36% and 50%, respectively, with 10 nmol/L dexamethasone, despite a 28% decrease of incorporation into total cell proteins. However, Northern blot analysis revealed that dexamethasone (1 to 1000 nmol/L) did not significantly alter the steady-state concentrations of apoB mRNA, suggesting that the net increase in apoB synthesis may involve increased translational efficiency. The intracellular retention and the rate and efficiency of apoB secretion were determined by pulse-chase experiments in which the hepatocytes were labeled with [35S]methionine for 10 minutes or 1 hour, and the disappearance of labeled apoB from the cells and its accumulation in the medium were monitored. Degradation of labeled apoB-100 after a 3-hour chase in both protocols was decreased from about 50% to 30%, whereas degradation of apoB-48 was decreased from 30% to 10% to 20% by treatment with 10 or 100 nmol/L dexamethasone. Additionally, the half-life of decay (time required for 50% of labeled cell apoB-100 to disappear from the peak of radioactivity following a 10-minute pulse) was increased by treatment with 10 nmol/L dexamethasone from 77 to 112 minutes, and the value for apoB-48 increased from 145 to 250 minutes. Treatment with 100 nmol/L dexamethasone also stimulated secretion of 35S-labeled apoB-100 and apoB-48 by twofold and 1.5-fold, respectively. The increased secretion of apoB-100 and apoB-48 after dexamethasone treatment was confirmed by immunoblot analysis for apoB mass, and the effect was relatively specific since albumin secretion was not significantly changed. We conclude that glucocorticoids promote the secretion of hepatic apoB-containing lipoproteins by increasing the net synthesis of apoB-100 and apoB-48 and by decreasing the intracellular degradation of newly synthesized apoB. An increased action of glucocorticoids coupled with a decreased ability of insulin to suppress these effects in insulin resistance can lead to hyperapobetalipoproteinemia and an increased risk of atherosclerosis.
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Affiliation(s)
- C N Wang
- Department of Biochemistry, University of Alberta, Edmonton, Canada
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23
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Day CP, Yeaman SJ. The biochemistry of alcohol-induced fatty liver. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1215:33-48. [PMID: 7948006 DOI: 10.1016/0005-2760(94)90089-2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- C P Day
- Department of Biochemistry, Medical School, University of Newcastle, UK
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24
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Yamashita H, Saheki S, Iwai M, Kobayashi N, Shimazu T. Reduced hepatic release of apoprotein B after enteral nutrition in rats. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1210:329-34. [PMID: 8305488 DOI: 10.1016/0005-2760(94)90237-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To investigate the effects of enteral and parenteral alimentation on VLDL release from the liver, a lipid-free liquid nutriment was continuously administered to free-moving rats via the oral cavity (oral group), stomach (enteral group) or superior caval vein (parenteral group). After 1-week of nutrition, the plasma VLDL concentrations were significantly lowered in the enterally-fed group. By immunoblotting assay using a specific antiserum, plasma contents of both apoprotein B-100 and B-48, the major components of rat apoprotein B, were found to be decreased in the enteral group, whereas only that of apoprotein B-48 was reduced in the parenteral group as compared with the oral group. Sucrose gradient centrifugation of the lipid droplets in the liver from the enteral group showed an increase of the free-triacylglycerol fraction with a concomitant increase of the apoprotein B-48-rich triacylglycerol fraction. These results suggest that enteral nutrition causes triacylglycerol accumulation in the liver, at least in part by impairment of lipoprotein release from the liver.
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Affiliation(s)
- H Yamashita
- Department of Medical Biochemistry, Ehime University School of Medicine, Japan
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25
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Affiliation(s)
- B V Howard
- Medlantic Research Institute, Washington, DC 20010
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26
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Asai K, Funaki C, Hayashi T, Yamada K, Naito M, Kuzuya M, Yoshida F, Yoshimine N, Kuzuya F. Dexamethasone-induced suppression of aortic atherosclerosis in cholesterol-fed rabbits. Possible mechanisms. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1993; 13:892-9. [PMID: 8499410 DOI: 10.1161/01.atv.13.6.892] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We investigated the mechanisms by which corticosteroids affect atherosclerosis. Male New Zealand White rabbits were injected with 0.125 mg dexamethasone (n = 10) or vehicle (control group, n = 10). Both groups were fed a 1% cholesterol diet for 8 weeks. Although the dexamethasone-treated animals exhibited a greater degree of hyperlipidemia, they exhibited significantly less atherosclerotic plaque of the aortic surface than control animals (7.8% versus 47.2%). Immunofluorescence study of the aortic plaque specimens showed that dexamethasone administration reduced both macrophages and T lymphocytes. In vitro, dexamethasone suppressed the proliferation and differentiation of U937 cells and inhibited uptake and degradation of beta-very low density lipoproteins by mouse peritoneal macrophages. These findings suggest that dexamethasone suppresses the development of atherosclerosis in the aorta of rabbits by inhibiting recruitment and proliferation of macrophages and the formation of foam cells in plaques.
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Affiliation(s)
- K Asai
- Department of Geriatrics, Nagoya University School of Medicine, Japan
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27
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Lespine A, Azema C, Gafvels M, Manent J, Dousset N, Chap H, Perret B. Lipoprotein lipase regulation in the cyclophosphamide-treated rabbit: dependence on nutritional status. J Lipid Res 1993. [DOI: 10.1016/s0022-2275(20)41316-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
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28
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Jansen H, van Tol A, Auwerx J, Skretting G, Staels B. Opposite regulation of hepatic lipase and lecithin: cholesterol acyltransferase by glucocorticoids in rats. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1128:181-5. [PMID: 1420288 DOI: 10.1016/0005-2760(92)90305-f] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Rats were treated with hydrocortisone, dexamethasone or triamcinolone for 4 days. The effect of treatment on hepatic lipase and lecithin:cholesterol acyltransferase (LCAT) mRNA levels and catalytic activities was determined. Hepatic lipase mRNA was not affected by hydrocortisone, but was decreased after dexamethasone (-28%) and triamcinolone (-54%). Hepatic lipase activity followed the same pattern, it was not affected by hydrocortisone and lowered by dexamethasone (-38%) and triamcinolone (-70%). The LCAT mRNA level in the liver was also not affected by hydrocortisone, but increased upon treatment with dexamethasone (+22%) and triamcinolone (+72%). Plasma LCAT, determined with an excess exogenous substrate (designated LCAT-II), tended to decrease after hydrocortisone treatment (-11%) and was higher after dexamethasone (+21%) and triamcinolone (+22%). The plasma cholesterol esterification rate (designated LCAT-I), determined by incubation of the plasma at 37 degrees C, followed the same pattern. The activity ratio of hepatic lipase/LCAT-II decreased from 1 in the controls to 0.51 after dexamethasone and 0.25 in the triamcinolone-treated animals. The plasma HDL cholesterol concentration in the different groups changed oppositely to the hepatic lipase/LCAT activity ratio. It is concluded that HDL cholesterol is raised by synthetic glucocorticoids due, among other factors, to a lowered hepatic lipase and an increased plasma LCAT activity. The influence of glucocorticoids on these enzymes is, at least partly, explained by the effects on the hepatic mRNA contents.
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Affiliation(s)
- H Jansen
- Department of Internal Medicine III, Erasmus University, Rotterdam, Netherlands
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Cassader M, Ruiu G, Gambino R, Alemanno N, Triolo G, Pagano G. Lipoprotein-apolipoprotein changes in renal transplant recipients: a 2-year follow-up. Metabolism 1991; 40:922-5. [PMID: 1895957 DOI: 10.1016/0026-0495(91)90067-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Renal transplantation modifies the dyslipidemia characteristic of chronic renal failure (CRF). The change in lipoprotein and lipid values of 51 transplant recipients, on cyclosporine and corticosteroid treatment, was studied during 2 years after transplantation to examine the short- and medium-term variations of lipid metabolism. Compared with control values of (all in mg/dL) triglycerides (Tg) 111 +/- 44, very-low-density lipoprotein (VLDL) Tg 69 +/- 18, total cholesterol (Chol) 201 +/- 32, VLDL-Chol 32 +/- 9, low-density lipoprotein (LDL) Chol 118 +/- 28, and high-density lipoprotein (HDL) Chol 50 +/- 10, uremic patients pretransplantation exhibited values of Tg 200 +/- 82 (P less than .001), VLDL-Tg 133 +/- 70 (P less than .001), Chol 193 +/- 51 (NS), VLDL-Chol 52 +/- 16 (P less than .001), LDL-Chol 100 +/- 37 (P less than .007), HDL-Chol 40 +/- 16 (P less than .001), which changed to Tg 118 +/- 18 (P less than .001), VLDL-Tg 64 +/- 45 (P less than .001), Chol 223 +/- 48 (P less than .006), VLDL-Chol 26 +/- 33 (P less than .001), LDL-Chol 134 +/- 43 (P less than .001), at HDL-Chol 63 +/- 21 (P less than .001) at 3 months and Tg 135 +/- 76, VLDL-Tg 81 +/- 62, Chol 218 +/- 55, VLDL-Chol 22 +/- 20, LDL-Chol 139 +/- 46, and HDL-Chol 58 +/- 18 at 24 months without evidence of a significative variations in the 3- to 24-month posttransplant period.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M Cassader
- Istituto di Medicina Interna, Università degli Studi di Torino, Italy
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Staels B, van Tol A, Chan L, Verhoeven G, Auwerx J. Variable effects of different corticosteroids on plasma lipids, apolipoproteins, and hepatic apolipoprotein mRNA levels in rats. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1991; 11:760-9. [PMID: 1903065 DOI: 10.1161/01.atv.11.3.760] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Treatment of male rats with hydrocortisone provoked a dose- and time-dependent decrease in plasma cholesterol concentration without a change in plasma triglyceride levels. In contrast, administration of triamcinolone and dexamethasone at equipotent glucocorticoid doses increased plasma cholesterol and triglyceride levels, respectively. Small effects on apolipoprotein E (apo E) and apo B mRNA levels were observed, but all corticosteroids increased apo A-I and apo A-IV mRNA and decreased apo A-II mRNA levels in the liver. Triamcinolone and dexamethasone, however, were three times more potent in stimulating hepatic apo A-IV gene expression than was hydrocortisone, whereas liver apo A-I and apo A-II mRNA levels were altered to a similar extent by all corticosteroids. Plasma apo A-I and apo B concentrations always varied in a similar fashion with their respective liver mRNA levels after administration of the distinct corticoids. For apo A-IV and apo E, discrepancies between plasma and liver mRNA levels after administration of the different steroids, however, point to additional regulatory effects on plasma apolipoprotein levels. We conclude that 1) in contrast to plasma apo A-I and apo B, alterations in plasma lipid, apo A-IV, and apo E levels depend on the type of corticosteroid used; and 2) glucocorticoids have a differential effect on hepatic mRNA levels of apo A-I and apo A-IV on the one hand and apo A-II on the other hand, an effect that may be of consequence in the process of reverse cholesterol transport.
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Affiliation(s)
- B Staels
- Laboratorium voor Experimentele Geneeskunde en Endocrinologie, Gasthuisberg, Belgium
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Haude W, Völcker CE. Hormonal effects on triacylglycerol secretion of rat liver. DIE NAHRUNG 1991; 35:1061-6. [PMID: 1800908 DOI: 10.1002/food.19910351016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The influence of epinephrine, norepinephrine, insulin, and prednisolone on the triacylglycerol (TG) secretion rate of rat liver was determined in vivo under different nutritional conditions (non-fasting, 10 and 16 h fasting, respectively). It was possible to estimate the triacylglycerol secretion rate by the Triton method without regard to fasting intervals. The subcutaneous administration of hormones was followed in all cases by changes of lipid parameters. Variations of secretion rate were found only by applications of norepinephrine, insulin, and prednisolone. Frequently, but not always, a change of free fatty acid (FFA) concentration in serum, that means a change of FFA mobilization in adipose tissue, was accompanied by an alteration of the TG secretion rate and in some cases by a change of TG concentration in serum in the same direction. We suggest that under these conditions the hormonal effect on TG secretion is realized by influence on the mobilization of FFA in adipose tissue. If the enhancement of FFA in serum is not followed by an increase of TG secretion, the elevated FFA influx into the liver is possibly used for oxidation or synthesis of phospholipids too. The role of nutritional factors was especially seen in 16 h fasting animals in which no rise of TG secretion rate was observed in spite of high FFA levels. In some cases reduced serum TG concentrations were observed without preceeding decreases of TG secretion rate out of the liver. Probably this effect is caused by increased clearance of serum TG.
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Affiliation(s)
- W Haude
- Institute of Pathological and Clinical Biochemistry, Ernst-Moritz-Arndt University, Greifswald, Federal Republic of Germany
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Franke H. Substructural alterations of liver parenchymal cells induced by xenobiotics. EXPERIMENTAL PATHOLOGY 1990; 39:139-55. [PMID: 2257919 DOI: 10.1016/s0232-1513(11)80176-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Xenobiotic-induced basic ultrastructural reactions of liver parenchymal cells as visualized with the basic method in ultrastructural research, the transmission electron microscopy, are described. There exists no "average hepatocyte", but even the normal liver is composed of a heterogeneous population of parenchymal cells revealing distinct ultrastructural and functional differences according to the intra-acinar location, circadian rhythms or metabolic and physiologic conditions. This liver cell heterogeneity is, as a rule, very much increased after acute or chronic exposure of the liver to any xenobiotic compound. Although most electron microscopic techniques are laborious and time consuming, electron microscopic research will play a growing role in analysing the response of the hepatocytes to drugs or other newly developed chemicals. There is no doubt that new methods and instrumental improvements will enable us to visualize more and more the primary site of action of any xenobiotic and the underlying molecular mechanisms in the hepatocytes followed by a sequence of events which lead to the manifestation of a complex reaction pattern composed of adaptation, injury, degeneration and reparation of the liver.
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Affiliation(s)
- H Franke
- Institute of Pathological Biochemistry, Friedrich Schiller University, DDR, Jena
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Mitamura T. Glucocorticoid-induced elevation of serum high-density lipoprotein-cholesterol and its reversal by adrenocorticotropin in the rat. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 917:121-30. [PMID: 3024735 DOI: 10.1016/0005-2760(87)90292-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The effect of administration of a high dose of glucocorticoid (triamcinolone) on serum lipids and lipoproteins was studied in rats. Changes in serum lipids, especially cholesterol, were most marked when 5 mg/kg body weight of triamcinolone was injected daily for 5 days. Serum lipoproteins were separated by ultracentrifugation followed by gel-filtration chromatography. Cholesterol distribution between apolipoprotein B-containing lipoproteins (very-low-density and low-density lipoproteins), high-density lipoprotein1 (HDL1), and HDL2 was determined after administration of triamcinolone with or without additional treatment with adrenocorticotropin (ACTH; Cortrosyn, 6 IU/rat). When triamcinolone was administered, cholesterol concentrations in HDL1 and HDL2 were elevated in a dose-dependent manner, but there was no significant change in apolipoprotein B-containing lipoprotein cholesterol levels. When ACTH was administered in combination with triamcinolone, the concentrations of all serum lipids except triacylglycerol were significantly lowered compared with rats treated with triamcinolone alone. HDL1-cholesterol concentration in serum was significantly (P less than 0.001) lowered from 69 +/- 13 mg/dl (mean +/- S.D.) in triamcinolone-treated rats to 36 +/- 4 mg/dl by the administration of ACTH plus triamcinolone. The additional administration of ACTH in triamcinolone-treated rats caused a slight, but significant, decrease in cholesterol concentration in apolipoprotein B-containing lipoproteins; however, HDL2-cholesterol level was not significantly affected, although there was a tendency for it to be lowered.
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Abstract
Methods for the study of hepatic lipoprotein synthesis and secretion have been described, and the advantages of each system discussed. Attention has been focused on intact cell systems. The isolated perfused liver constitutes a standard of comparison for all others, even though it, too, has limitations. Table IV below gives our assessment of some of the advantages and disadvantages of the techniques for studying hepatic lipoprotein biosynthesis.
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Steiner G, Haynes FJ, Yoshino G, Vranic M. Hyperinsulinemia and in vivo very-low-density lipoprotein-triglyceride kinetics. THE AMERICAN JOURNAL OF PHYSIOLOGY 1984; 246:E187-92. [PMID: 6364843 DOI: 10.1152/ajpendo.1984.246.2.e187] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The effect of hyperinsulinemia (2 wk of twice daily NPH insulin) on the kinetics of very-low-density lipoprotein (VLDL)-triglyceride (TG) was studied in rats. To avoid profound hypoglycemia the rats were allowed sucrose ad libitum. Two control groups were needed: chow only and ad libitum sucrose-supplemented (high-CHO). The insulin-treated rats had 15 times higher IRI and 50% lower plasma glucose levels than either control group. Their TG production exceeded and their TG concentrations were less than those of either control group. This indicated that their TG removal was increased even more than their TG production. This increase in TG production occurred despite lower plasma free fatty acid (FFA) levels, suggesting that a greater proportion of TG fatty acids came from a source other than FFA. Compared with chow controls, high-CHO controls had the same peripheral IRI, a slight increase in TG production, and an increase in TG concentration. The differences between the effects of CHO supplementation alone or together with injected insulin may relate to the IRI and/or the route of access of insulin (peripheral vs. portal). The present studies indicate that hyperinsulinemia, either directly or indirectly, accelerates triglyceride turnover.
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Johnston D, Alberti K. 3 Hormonal control of ketone body metabolism in the normal and diabetic state. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0300-595x(82)80019-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Hörl WH, Hörl M, Heidland A. [Alterations of fat metabolism in renal disease - pathogenetic mechanisms (author's transl)]. KLINISCHE WOCHENSCHRIFT 1982; 60:327-36. [PMID: 6122754 DOI: 10.1007/bf01721622] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Hypertriglyceridaemia is often observed in patients (1) with chronic renal insufficiency, (2) on haemodialysis and (3) after successful renal transplantation. HDL cholesterol is reduced in all three groups of patients and plasma cholesterol is elevated after renal transplantation. In these three patient groups type IV hyperlipoproteinaemia is found most frequently and after renal transplantation there is a relative increase in the incidence of type II hyperlipoproteinaemia. The role of glucagon resistance and carnitine deficiency in the alteration of fat metabolism seen in patients with chronic renal failure and patients on haemodialysis is discussed. Other factors which may influence fat metabolism in uraemia include calcium and vitamin D status as well as beta adrenergic receptor blocking agents and diuretics. Steroid therapy may be one cause of the hypercholesterolaemia and hypertriglyceridaemia seen after renal transplantation. PHLP lipase activity is reduced in all three groups of patients. In nephrotic syndrome, if hypercholesterolaemia occurs, the HDL cholesterol fraction is increased and thus the cardiovascular risk may be lower than in the three patient group mentioned above.
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Chapter 5 Phosphatidate metabolism and its relation to triacylglycerol biosynthesis. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0167-7306(08)60009-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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40
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Cole TG, Wilcox HG, Heimberg M. Effects of adrenalectomy and dexamethasone on hepatic lipid metabolism. J Lipid Res 1982. [DOI: 10.1016/s0022-2275(20)38176-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Abstract
Hyperlipidemia is common in patients with renal disease. This fact may be of great clinical relevance in view of the overwhelming evidence associating disturbed lipid metabolism and atherogenesis. Thus, hyperlipidemia may predispose to vascular disease in patients with chronic renal disorders and premature atherosclerosis could be an important risk in renal disease and a major factor limiting survival of patients on long-term maintenance hemodialysis. The aim of the present review is to present a brief but clinically relevant description of lipoprotein physiology and then to survey the now considerable literature concerned with lipoprotein and thus lipid abnormalities in patients with renal disease. A particular emphasis is placed on the role of the plasma lipoproteins in forming an integrated and controlled pathway for lipid metabolism, and how altered regulatory control within the pathway may be associated with pathogenic mechanisms. Finally, the evidence for accelerated development of vascular disease associated with these lipid abnormalities is briefly considered.
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Chan MK, Persaud JW, Varghese Z, Fernando ON, Moorhead JF. Fat clearances and hyperlipidaemia in renal allograft recipients--the role of insulin resistance. Clin Chim Acta 1981; 114:61-7. [PMID: 7018745 DOI: 10.1016/0009-8981(81)90228-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The mechanism of hyperlipidaemia in renal allograft recipients was investigated in 19 patients randomly selected from a cohort of 54 patients with functioning renal allografts. Serum cholesterol, triglyceride and high-density lipoprotein cholesterol concentrations as well as plasma immunoreactive insulin levels were measured in fasting blood samples. Intravenous fat tolerance tests were performed before and 15 min after heparin administration. Renal allograft recipients had reduced fractional clearance rates of Intralipid and a positive correlation was demonstrated between plasma immunoreactive insulin levels and serum triglyceride concentrations. Plasma immunoreactive insulins also correlated inversely with fractional clearance rates of Intralipid. It was concluded that both increased production and decreased removal of lipoproteins contribute to the hyperlipidaemia and that insulin resistance due to corticosteroids was the centre of the problem.
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43
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Bates EJ, Saggerson ED. Effects of adrenalectomy and cortisol treatment on dihydroxyacetone phosphate acyltransferase activity in rat liver. FEBS Lett 1981; 128:230-2. [PMID: 7262315 DOI: 10.1016/0014-5793(81)80087-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Krausz Y, Bar-On H, Shafrir E. Origin and pattern of glucocorticoid-induced hyperlipidemia in rats. Dose-dependent bimodal changes in serum lipids and lipoproteins in relation to hepatic lipogenesis and tissue lipoprotein lipase activity. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 663:69-82. [PMID: 6111353 DOI: 10.1016/0005-2760(81)90195-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Rats maintained for five days on a low dose of triamcinolone (0.5 mg/kg) showed a 2-fold increase in serum triacylglycerol concentration, paralleled by a rise in all very low density lipoprotein (VLDL) components but no significant change in serum cholesterol or high density lipoproteins (HDL). In contrast, a high dose of triamcinolone (12.5 mg/kg) produced a fall in triacylglycerol and VLDL to the range of control levels coincident with doubling in serum cholesterol and HDL. The rise in VLDL was attributed in a large part to enhanced hepatic fatty acid synthesis as evident from the marked rises in activity of rate-limiting enzymes of lipogenesis and in 3H incorporation into liver and serum fatty acids from in vivo administered 3H2O. The induction of fatty acid synthesis was linked to pronounced hyperinsulinemia, elicited by the triamcinolone treatment, to which the liver remained selectively responsive, contrary to the general insulin antagonism in peripheral tissues. Triamcinolone treatment also resulted in small rises in serum glucagon but these changes did not appear to be of importance for the observed bimodal serum lipoprotein perturbations. Dexamethasone, prednisolone and cortisol, administered in doses equipotent to 0.5 mg/kg triamcinolone, produced similar changes in the levels of serum triacylglycerol and insulin and activities of hepatic enzymes of lipogenesis.
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Smialowicz RJ, Weil CM, Marsh P, Riddle MM, Rogers RR, Rehnberg BF. Biological effects of long-term exposure of rats to 970-MHz radiofrequency radiation. Bioelectromagnetics 1981; 2:279-84. [PMID: 7306224 DOI: 10.1002/bem.2250020309] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Rats (N = 16) exposed individually in circularly polarized waveguides to 970-MHz electromagnetic radiation (SAR = 2.5 mW/g, 22 h daily for 70 consecutive days) had significantly higher serum levels of triglycerides, albumin, and total protein compared with sham-irradiated controls. No difference was observed in the weights, hematologic profile, or in vitro lymphocyte responses to mitogens between these two groups. The higher serum levels of triglycerides in radiofrequency-radiation-exposed rats suggest a non-specific stress reaction.
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Johnston DG, Alberti KG, Nattrass M, Barnes AJ, Bloom SR, Joplin GF. Hormonal and metabolic rhythms in Cushing's syndrome. Metabolism 1980; 29:1046-52. [PMID: 7001175 DOI: 10.1016/0026-0495(80)90215-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Hormone and metabolite profiles were investigated over a 12-hr period in six patients with Cushing's syndrome, ten age- and sex-matched normal controls, and six moderately obese subjects matched for weight with the patient group. Mean diurnal plasma cortisol levels were 563 +/- 74 nmole/liter in the patients, 275 +/- 22 nmole/liter in normal controls and 241 +/- 32 nmole/liter in obese subjects, with total loss of diurnal changes in Cushing's syndrome. Fasting blood glucose concentration was similar in all groups although mild hyperglycemia occurred after meals in the Cushing's patients compared with normal and obese subjects (mean 12-hr blood glucose: Cushing's 6.31 +/- 0.39 mmole/liter; normal controls, 5.32 +/- 0.14 mmole/liter, p < 0.01; obese subjects, 5.41 +/- 0.18 mmole/liter, p < 0.05) despite marked hyperinsulinemia (mean 12-hr serum insulin: Cushing's 57.3 +/- 18.2 mU/liter; normal controls, 19.7 +/- 2.5 mU/liter, p < 0.02; obese subjects, 18.1 +/- 4.0 mU/liter, p < 0.05). Concentrations of the gluconeogenic precursors lactate, pyruvate, and alanine were raised in Cushing's syndrome, particularly postprandially. Plasma nonesterified fatty acids (NEFA), blood glycerol, and blood ketone body concentrations were comparable in all three groups although the normal diurnal variation in circulating NEFA and ketone body levels was lost in Cushing's syndrome. Serum triglyceride (TG) concentrations were grossly elevated in the Cushing's patients (mean 12-hr serum TG: Cushing's 3.51 +/- 1.23 mmole/liter; normal controls 0.89 +/- 0.19 mmole/liter, p < 0.02; obese subjects, 0.93 +/- 0.23 mmole/liter, p < 0.05) and correlated positively with serum insulin levels. Plasma glucagon concentrations were raised in Cushing's syndrome (mean 12-hr plasma glucagon: Cushing's 23.2 +/- 3.7 pmole/liter; normal controls 12.3 +/- 1.5 pmole/liter p < 0.01; obese subjects 12.2 +/0 2.0 pmole/liter, p < 0.02) and correlated positively with the serum cortisol but not with blood alanine, suggesting that some stimulatory factor other than alanine was responsible. The metabolic effects of chronic glucocorticoid excess thus may not be explained on the basis of obesity alone. Compensatory hyperinsulinemia limits the disturbance of carbohydrate and lipid metabolism in Cushing's syndrome but may be important in production of the hypertriglyceridemia observed.
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Garfield SA, Scott AC, Cardell RR. Alterations in hepatic fine structure after chronic exposure of rats to dexamethasone. Anat Rec (Hoboken) 1978; 192:73-87. [PMID: 212964 DOI: 10.1002/ar.1091920107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The objective of this study was to determine the effects of chronic dexamethasone (DEX) administration on hepatic ultrastructure and to correlate these changes with plasma lipoprotein levels. Electron microscopic studies were made of hepatocytes from male rats killed 1, 3 and 5 days after DEX (2 mg, twice per day) administration. Three days after treatment plasma lipoprotein levels were highest and hepatocytes contained regions of the cytosome rich in elements of the smooth endoplasmic reticulum (SER). Osmiophilic particles were present in the tubules and vesicles of the SER, in the saccules and vacuoles of the Golgi complex, in secretory vesicles near the cell surface and in the space of Disse. DEX treatments also caused hepatocytes to accumulate tightly packed masses of beta-particles of glycogen in some regions of the cell while other areas displayed dispersed glycogen particles that were associated with the SER. These observations are consistent with the hypothesis that glucocorticoids 1. cause an elevation of plasma lipoprotein levels by increasing hepatic synthesis and secretion of VLDL, which involves the sequential participation of the ER, the Golgi complex and exocytosis of VLDL-containing vacuoles into the space of Disse, and 2. produce a change in the nature of the association of glycogen particles with the SER membranes in response to the physiological state of the animal.
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Mordasini R, Frey F, Flury W, Klose G, Greten H. Selective deficiency of hepatic triglyceride lipase in uremic patients. N Engl J Med 1977; 297:1362-6. [PMID: 200841 DOI: 10.1056/nejm197712222972502] [Citation(s) in RCA: 133] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
To investigate the pathogenesis of hypertriglyceridemia in patients with renal disease we measured plasma lipoprotein composition as well as hepatic triglyceride lipase and lipoprotein lipase in post-heparin plasma. Three groups with renal disease were studied: conservatively treated chronic uremia; patients undergoing maintenance hemodialysis; and renal-allograft recipients. A selective decrease of hepatic triglyceride lipase with normal lipoprotein lipase was found in conservatively treated uremia and in patients undergoing hemodialysis. Elevated levels of very-low-density lipoproteins and increased triglycerides in low-density lipoproteins occurred in these patients. In contrast, hepatic triglyceride lipase and lipoprotein lipase were both normal in patients after renal transplantation who had Type II hyperlipoproteinemia as a common lipoprotein pattern with increased low-density-lipoprotein cholesterol and decreased high-density-lipoprotein cholesterol concentrations. The accumulation of a triglyceride-rich low-density lipoprotein in the majority of patients with renal disease may be the consequence of low hepatic triglyceride lipase.
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50
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Gregg RC, Diamond A, Mondon CE, Reaven GM. The effects of chronic uremia and dexamethasone on triglyceride kinetics in the rat. Metabolism 1977; 26:875-82. [PMID: 195180 DOI: 10.1016/0026-0495(77)90006-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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