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Shiomi M. The History of the WHHL Rabbit, an Animal Model of Familial Hypercholesterolemia (I) - Contribution to the Elucidation of the Pathophysiology of Human Hypercholesterolemia and Coronary Heart Disease. J Atheroscler Thromb 2019; 27:105-118. [PMID: 31748469 PMCID: PMC7049476 DOI: 10.5551/jat.rv17038-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Animal models that closely resemble both human disease findings and their onset mechanism have contributed to the advancement of biomedical science. The Watanabe heritable hyperlipidemic (WHHL) rabbit and its advanced strains (the coronary atherosclerosis-prone and the myocardial infarction-prone WHHL rabbits) developed at Kobe University (Kobe, Japan), an animal model of human familial hypercholesterolemia, have greatly contributed to the elucidation of the pathophysiology of human lipoprotein metabolism, hypercholesterolemia, atherosclerosis, and coronary heart disease, as described below. 1) The main part of human lipoprotein metabolism has been elucidated, and the low-density lipoprotein (LDL) receptor pathway hypothesis derived from studies using fibroblasts was proven in vivo. 2) Oxidized LDL accumulates in the arterial wall, monocyte adhesion molecules are expressed on arterial endothelial cells, and monocyte-derived macrophages infiltrate the arterial intima, resulting in the formation and progression of atherosclerosis. 3) Coronary lesions differ from aortic lesions in lesion composition. 4) Factors involved in the development of atherosclerosis differ between the coronary arteries and aorta. 5) The rupture of coronary lesions requires secondary mechanical forces, such as spasm, in addition to vulnerable plaques. 6) Specific lipid molecules in the blood have been identified as markers of the progression of coronary lesions. At the end of the breeding of the WHHL rabbit family at Kobe University, this review summarizes the history of the development of the WHHL rabbit family and their contribution to biomedical science.
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Affiliation(s)
- Masashi Shiomi
- Institute for Experimental Animals, Kobe University Graduate School of Medicine
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Fan J, Chen Y, Yan H, Liu B, Wang Y, Zhang J, Chen YE, Liu E, Liang J. Genomic and Transcriptomic Analysis of Hypercholesterolemic Rabbits: Progress and Perspectives. Int J Mol Sci 2018; 19:E3512. [PMID: 30413026 PMCID: PMC6274909 DOI: 10.3390/ijms19113512] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 11/04/2018] [Accepted: 11/05/2018] [Indexed: 12/22/2022] Open
Abstract
Rabbits (Oryctolagus cuniculus) are one of the most widely used animal models for the study of human lipid metabolism and atherosclerosis because they are more sensitive to a cholesterol diet than other experimental animals such as rodents. Currently, two hypercholesterolemic rabbit models are frequently used for atherosclerosis studies. One is a cholesterol-fed wild-type rabbit and the other is the Watanabe heritable hyperlipidemic (WHHL) rabbit, which is genetically deficient in low density lipoprotein (LDL) receptor function. Wild-type rabbits can be easily induced to develop severe hypercholesterolemia with a cholesterol-rich diet due to the marked increase in hepatically and intestinally derived remnant lipoproteins, called β-very low density lipoproteins (VLDL), which are rich in cholesteryl esters. WHHL rabbits are characterized by elevated plasma LDL levels on a standard chow diet, which resembles human familial hypercholesterolemia. Therefore, both rabbit models develop aortic and coronary atherosclerosis, but the elevated plasma cholesterol levels are caused by completely different mechanisms. In addition, cholesterol-fed rabbits but not WHHL rabbits exhibit different degrees of hepatosteatosis. Recently, we along with others have shown that there are many differentially expressed genes in the atherosclerotic lesions and livers of cholesterol-fed rabbits that are either significantly up- or down-regulated, compared with those in normal rabbits, including genes involved in the regulation of inflammation and lipid metabolism. Therefore, dietary cholesterol plays an important role not only in hypercholesterolemia and atherosclerosis but also in hepatosteatosis. In this review, we make an overview of the recent progress in genomic and transcriptomic analyses of hypercholesterolemic rabbits. These transcriptomic profiling data should provide novel insight into the relationship between hypercholesterolemia and atherosclerosis or hepatic dysfunction caused by dietary cholesterol.
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Affiliation(s)
- Jianglin Fan
- Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi 409-3898, Japan.
- Department of Pathology, Xi'an Medical University, Xi'an 710021, China.
| | - Yajie Chen
- Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi 409-3898, Japan.
| | - Haizhao Yan
- Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Yamanashi 409-3898, Japan.
| | - Baoning Liu
- Research Institute of Atherosclerotic Disease and Laboratory Animal Center, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
| | - Yanli Wang
- Department of Pathology, Xi'an Medical University, Xi'an 710021, China.
| | - Jifeng Zhang
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA.
| | - Y Eugene Chen
- Center for Advanced Models for Translational Sciences and Therapeutics, University of Michigan Medical Center, Ann Arbor, MI 48109, USA.
| | - Enqi Liu
- Research Institute of Atherosclerotic Disease and Laboratory Animal Center, School of Medicine, Xi'an Jiaotong University, Xi'an 710061, China.
| | - Jingyan Liang
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China.
- Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Yangzhou University, Yangzhou 225001, China.
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou 225001, China.
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Hyperlipidemia-associated gene variations and expression patterns revealed by whole-genome and transcriptome sequencing of rabbit models. Sci Rep 2016; 6:26942. [PMID: 27245873 PMCID: PMC4887883 DOI: 10.1038/srep26942] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 05/11/2016] [Indexed: 12/13/2022] Open
Abstract
The rabbit (Oryctolagus cuniculus) is an important experimental animal for studying human diseases, such as hypercholesterolemia and atherosclerosis. Despite this, genetic information and RNA expression profiling of laboratory rabbits are lacking. Here, we characterized the whole-genome variants of three breeds of the most popular experimental rabbits, New Zealand White (NZW), Japanese White (JW) and Watanabe heritable hyperlipidemic (WHHL) rabbits. Although the genetic diversity of WHHL rabbits was relatively low, they accumulated a large proportion of high-frequency deleterious mutations due to the small population size. Some of the deleterious mutations were associated with the pathophysiology of WHHL rabbits in addition to the LDLR deficiency. Furthermore, we conducted transcriptome sequencing of different organs of both WHHL and cholesterol-rich diet (Chol)-fed NZW rabbits. We found that gene expression profiles of the two rabbit models were essentially similar in the aorta, even though they exhibited different types of hypercholesterolemia. In contrast, Chol-fed rabbits, but not WHHL rabbits, exhibited pronounced inflammatory responses and abnormal lipid metabolism in the liver. These results provide valuable insights into identifying therapeutic targets of hypercholesterolemia and atherosclerosis with rabbit models.
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Fang C, Ning B, Waqar AB, Niimi M, Li S, Satoh K, Shiomi M, Ye T, Dong S, Fan J. Bisphenol A exposure induces metabolic disorders and enhances atherosclerosis in hyperlipidemic rabbits. J Appl Toxicol 2015; 35:1058-70. [DOI: 10.1002/jat.3103] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/03/2014] [Accepted: 11/20/2014] [Indexed: 12/15/2022]
Affiliation(s)
- Chao Fang
- Key Laboratory of Urban Environment and Health; Institute of Urban Environment, Chinese Academy of Sciences; Xiamen China
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
| | - Bo Ning
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
| | - Ahmed Bilal Waqar
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
| | - Manabu Niimi
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
| | - Shen Li
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
| | - Kaneo Satoh
- Department of Laboratory Medicine, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
| | - Masashi Shiomi
- Institute for Experimental Animals; Kobe University School of Medicine; Kobe Japan
| | - Ting Ye
- Key Laboratory of Urban Environment and Health; Institute of Urban Environment, Chinese Academy of Sciences; Xiamen China
| | - Sijun Dong
- Key Laboratory of Urban Environment and Health; Institute of Urban Environment, Chinese Academy of Sciences; Xiamen China
| | - Jianglin Fan
- Key Laboratory of Urban Environment and Health; Institute of Urban Environment, Chinese Academy of Sciences; Xiamen China
- Department of Molecular Pathology, Interdisciplinary Graduate School of Medicine and Engineering; University of Yamanashi; Yamanashi Japan
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Roy H, Bhardwaj S, Babu M, Kokina I, Uotila S, Ahtialansaari T, Laitinen T, Hakumaki J, Laakso M, Herzig KH, Ylä-Herttuala S. VEGF-A, VEGF-D, VEGF receptor-1, VEGF receptor-2, NF-kappaB, and RAGE in atherosclerotic lesions of diabetic Watanabe heritable hyperlipidemic rabbits. FASEB J 2006; 20:2159-61. [PMID: 16935942 DOI: 10.1096/fj.05-5029fje] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Plaque angiogenesis may be associated with the development of unstable and vulnerable plaques. Vascular endothelial growth factors (VEGFs) are potent angiogenic factors that can affect plaque neovascularization. Our objective was to determine the effect of diabetes on atherosclerosis and on the expression of angiogenesis-related genes in atherosclerotic lesions. Alloxan was used to induce diabetes in male Watanabe heritable hyperlipidemic (WHHL) rabbits that were sacrificed 2 and 6 months after the induction of diabetes. Nondiabetic WHHL rabbits served as controls. Blood glucose (Glc), serum-free fatty acids (FFA), and serum triglyceride levels were significantly higher in diabetic rabbits. Accelerated atherogenesis was observed in the diabetic WHHL rabbits together with increased intramyocellular lipids (IMCL), as determined by 1H-NMR spectroscopy. Atherosclerotic lesions in the diabetic rabbits had an increased content of macrophages and showed significant increases in immunostainings for vascular endothelial growth factor (VEGF)-A, VEGF-D, VEGF receptor-1, VEGF receptor-2, RAGE, and NF-kappaB. VEGF-A165 and VEGFR-2 mRNA levels were significantly increased in aortas of the diabetic rabbits, where a trend toward increased plaque vascularization was also observed. These results suggest that diabetes accelerates atherogenesis, up-regulates VEGF-A, VEGF-D, and VEGF receptor-2 expression, and increases NF-kappaB, RAGE, and inflammatory responses in atherosclerotic lesions in WHHL rabbits.
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Affiliation(s)
- Himadri Roy
- Department of Biotechnology and Molecular Medicine, A. I. Virtanen Institute for Molecular Sciences, University of Kuopio, Finland
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Gonzales JA, Szeto A, Mendez AJ, Zaias J, Paredes J, Caperton CV, Llabre MM, Levine JE, Goldberg RB, Schneiderman N, McCabe PM. Effect of behavioral interventions on insulin sensitivity and atherosclerosis in the Watanabe heritable hyperlipidemic rabbit. Psychosom Med 2005; 67:172-8. [PMID: 15784780 DOI: 10.1097/01.psy.0000155674.95497.ab] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE A previous study suggested that insulin metabolic variables play a role in the progression of atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits. The present study sought to determine: 1) if young, individually caged WHHLs are insulin-resistant relative to New Zealand white (NZW) rabbits and 2) whether dietary or exercise interventions can improve insulin sensitivity and slow the development of atherosclerosis in these animals. METHODS Forty-two WHHLs were assigned to a dietary, exercise, or control condition, and 12 NZWs were used as a comparison control group. The intervention ran from 3 to 7 months of age, and all animals received an intravenous glucose tolerance test at the beginning and end of the intervention. RESULTS WHHLs were insulin-resistant relative to NZWs at 3 months of age. Whereas the dietary intervention was effective in controlling insulin resistance, WHHLs in the exercise group without dietary restriction and the control group exhibited significant increases in insulin resistance. No intervention significantly influenced the progression of atherosclerosis. CONCLUSIONS Young WHHLs are insulin-resistant during an early period when atherosclerosis is developing rapidly. Dietary restriction, but not exercise without weight control, is effective in controlling insulin metabolic variables in the WHHL model. Although dietary intervention can reduce cardiovascular risk factors such as insulin resistance, it is not effective in slowing the development of atherosclerosis in these genetically dyslipidemic animals. Similarly, exercise training, without dietary control, does not influence the progression of disease in WHHLs.
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Affiliation(s)
- Julie A Gonzales
- Department of Psychology, University of Miami, Coral Gables, FL 33124, USA
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Koike T, Liang J, Wang X, Ichikawa T, Shiomi M, Liu G, Sun H, Kitajima S, Morimoto M, Watanabe T, Yamada N, Fan J. Overexpression of Lipoprotein Lipase in Transgenic Watanabe Heritable Hyperlipidemic Rabbits Improves Hyperlipidemia and Obesity. J Biol Chem 2004; 279:7521-9. [PMID: 14660566 DOI: 10.1074/jbc.m311514200] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lipoprotein lipase (LPL) is the rate-limiting enzyme for the hydrolysis of the triglyceride-rich lipoproteins and plays a critical role in lipoprotein and free fatty acid metabolism. Genetic manipulation of LPL may be beneficial in the treatment of hypertriglyceridemias, but it is unknown whether increased LPL activity may be effective in lowering plasma cholesterol and improving insulin resistance in familial hypercholesterolemic patients. To test the hypothesis that stimulation of LPL expression may be used as an adjunctive therapy for treatment of homozygous familial hypercholesterolemia, we have generated transgenic (Tg) Watanabe heritable hyperlipidemic (WHHL) rabbits that overexpress the human LPL transgene and compared their plasma lipid levels, glucose metabolism, and body fat accumulation with those of non-Tg WHHL rabbits. Overexpression of LPL dramatically ameliorated hypertriglyceridemia in Tg WHHL rabbits. Furthermore, increased LPL activity in male Tg WHHL rabbits also corrected hypercholesterolemia (544 +/- 52 in non-Tg versus 227 +/- 29 mg/dl in Tg, p < 0.01) and reduced body fat accumulation by 61% (323 +/- 27 in non-Tg versus 125 +/- 21ginTg, p < 0.01), suggesting that LPL plays an important role in mediating plasma cholesterol homeostasis and adipose accumulation. In addition, overexpression of LPL significantly suppressed high fat diet-induced obesity and insulin resistance in Tg WHHL rabbits. These results imply that systemic elevation of LPL expression may be potentially useful for the treatment of hyperlipidemias, obesity, and insulin resistance.
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Affiliation(s)
- Tomonari Koike
- Cardiovascular Disease Laboratory, Department of Pathology, Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
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McCabe PM, Gonzales JA, Zaias J, Szeto A, Kumar M, Herron AJ, Schneiderman N. Social environment influences the progression of atherosclerosis in the watanabe heritable hyperlipidemic rabbit. Circulation 2002; 105:354-9. [PMID: 11804992 DOI: 10.1161/hc0302.102144] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Although there is evidence that emotionally stressful behavior can accelerate the progression of atherosclerosis, there is less data to support the notion that affiliative social behavior can slow disease progression. The present study examines the influence of social environment on the progression of atherosclerosis in the Watanabe Heritable Hyperlipidemic (WHHL) rabbit, a model that spontaneously develops lesions because of a genetic defect in lipoprotein clearance. METHODS AND RESULTS WHHL rabbits were assigned to 1 of 3 social or behavioral groups: an unstable group, in which unfamiliar rabbits were paired daily, with the pairing switched each week; a stable group, in which littermates were paired daily for the entire study; and an individually caged group. The stable group exhibited more affiliative social behavior and less agonistic behavior than the unstable group and significantly less aortic atherosclerosis than each of the other 2 groups. Although the unstable and individually caged groups had comparable aortic lesion areas, the severity of the disease progressed faster in the unstable group, as indexed by a larger area of calcification and increased fibrous cap thickness in complex lesions. The unstable group showed increased agonistic behavior and signs of chronic adrenocortical and gonadal activation, whereas the individually caged group was relatively sedentary, had low glucocorticoid levels, and was hyperinsulinemic compared with the other groups. CONCLUSIONS The present study demonstrates that social environment can slow, as well as accelerate, the progression of atherosclerosis. It also emphasizes the importance of behavioral factors in atherogenesis, even in a model of disease with strong genetic determinants.
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Affiliation(s)
- Philip M McCabe
- Department of Psychology, University of Miami, Coral Gables, Florida, USA.
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Zhang B, Shiomi M, Tanaka H, Mei J, Fan P, Tsujita Y, Horikoshi H, Saku K. Effects of high-dose troglitaz one on insulin sensitivity and beta-cell function in Watanabe heritable hyperlipidemic rabbits. Eur J Drug Metab Pharmacokinet 2001; 26:185-92. [PMID: 11695719 DOI: 10.1007/bf03190395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
UNLABELLED To clarify the dose-response effects of troglitazone on insulin sensitivity and beta-cell function, we examined the effects of high-dose troglitazone (100 mg/day per animal, administered as a food admixture) on glucose and insulin metabolism in hyperinsulinemic Watanabe heritable hyperlipidemic (WHHL) rabbits, and compared the results with our previous results with low-dose troglitazone (10 mg /day per animal). MATERIALS AND METHODS Glucose and insulin metabolism were quantitatively characterized by a minimal model technique as reported previously. RESULTS When troglitazone was administrated at a high dose for 6 months, it reduced hyperinsulinemia as reflected by a reduced basal (steady-state) insulin concentration lb and the insulin response to a glucose load, improved beta-cell function as reflected by decreased second-phase post-hepatic insulin delivery to glucose phi2, and reduced insulin resistance as reflected by increased insulin sensitivity to glucose disposal Si, without affecting glucose tolerance as reflected by an unchanged rate of glucose utilization Kg or insulin-independent glucose disposal Sg. The reductions in Ib and phi2 and the increases in Si in WHHL rabbits treated with a high dose of troglitazone were greater (p<0.05) than those observed in WHHL rabbits treated with a low dose of troglitazone, as assessed by a two-way repeated measures analysis of variance and the Wilcoxon-Mann-Whitney test. CONCLUSION In WHHL rabbits, troglitazone dose-dependently reduced hyperinsulinemia, improved beta-cell function, and increased insulin sensitivity.
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Affiliation(s)
- B Zhang
- Department of Internal Medicine, Fukuoka University, Japan
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de Roos B, Caslake MJ, Ardern HA, Martin Benson G, Suckling KE, Packard CJ. Insulin resistance in the St. Thomas' mixed hyperlipidaemic (SMHL) rabbit, a model for familial combined hyperlipidaemia. Atherosclerosis 2001; 156:249-54. [PMID: 11395020 DOI: 10.1016/s0021-9150(00)00614-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The St. Thomas mixed hyperlipidaemic (SMHL) rabbit exhibits an inherited hyperlipidaemia similar to that seen in familial combined hyperlipidaemia (FCHL). In this study, we investigated whether the SMHL rabbit is insulin resistant, a condition often associated with FCHL. Six young and six mature combined hyperlipidaemic SMHL rabbits, age/sex matched New Zealand White (NZW) control rabbits and six young hypercholesterolaemic Watanabe heritable hyperlipidaemic (WHHL) control rabbits were fed a 0.08% (w/w) cholesterol-enriched diet for at least 1 month prior to the start of the experiment. We performed an oral glucose tolerance test after an overnight fast by dosing the rabbits with a solution of 1 g of glucose per kg body weight. Blood was withdrawn just before and 15, 30, 45, 60 and 120 min after administration of the oral glucose dose. Plasma glucose levels were similar in SMHL, WHHL and NZW rabbits throughout the oral glucose tolerance test. Fasting glucose levels were slightly increased in WHHL rabbits but not in young and adult SMHL rabbits as compared to NZW rabbits. The area under the curve (AUC) for the insulin response was significantly increased for both young (P<0.05) and mature (P<0.05) SMHL rabbits, and in WHHL rabbits, compared with NZW rabbits. The AUC for the ratio of glucose:insulin response to the glucose dose was decreased in young and mature SMHL rabbits (P<0.05 and P<0.01, respectively) and in young WHHL rabbits (P<0.05), compared with NZW rabbits. Only WHHL rabbits showed an increased AUC for the non-esterified fatty acid response compared to NZW rabbits. Log-transformed plasma triglycerides values were significantly correlated with the log-transformed AUC for the insulin response in young SMHL rabbits (r=0.81; P<0.05) and with the AUC for the insulin response in mature SMHL rabbits (r=0.84; P<0.05). WHHL rabbits showed no significant correlation. In conclusion, SMHL rabbits are insulin resistant, the severity of which appears to increase with age. Therefore, the SMHL rabbit offers a valuable animal model in which to study the relation between hypertriglyceridaemia and insulin resistance.
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Affiliation(s)
- B de Roos
- Department of Pathological Biochemistry, 4th Floor, Queen Elizabeth Building, Royal Infirmary, Glasgow G31 2ER, Scotland, UK.
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Shiomi M, Ito T, Tsukada T, Tsujita Y, Horikoshi H. Combination treatment with troglitazone, an insulin action enhancer, and pravastatin, an inhibitor of HMG-CoA reductase, shows a synergistic effect on atherosclerosis of WHHL rabbits. Atherosclerosis 1999; 142:345-53. [PMID: 10030386 DOI: 10.1016/s0021-9150(98)00259-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We examined whether improving insulin resistance augments the antiatherosclerotic effect of LDL reduction. Since WHHL rabbits show hyperinsulinemia and insulin resistance, we administered troglitazone (100 mg/kg), an insulin action enhancer, pravastatin sodium (50 mg/kg), an HMG CoA reductase inhibitor, and a combination of both drugs to 2-month-old WHHL rabbits for 32 weeks. As compared to the control, total cholesterol levels in the plasma and LDL were decreased significantly by 20% in the pravastatin and combination groups. Basal immunoreactive insulin levels and insulin index were decreased significantly by approximately 50% in the troglitazone and combination groups. Surface lesion area of atherosclerosis on the thoracic aorta was decreased significantly by 36% in the combination group and was less in the troglitazone group. Coronary atherosclerosis was decreased significantly by 39% in the combination group and was less in the pravastatin and troglitazone groups. The collagen content in the plaques was decreased in the troglitezone and combination groups and the extracellular lipid deposits were decreased in the pravastatin and combination groups. The incidence and severity of xanthomata in the digital joints were also decreased significantly in the three treated groups. In conclusion, the antiatherogenic effect of the combination treatment is stronger than that of the monotherapy.
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Affiliation(s)
- M Shiomi
- Institute for Experimental Animals, Kobe University School of Medicine, Japan
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12
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Saku K, Zhang B, Ohta T, Arakawa K. Effects of troglitazone on serum lipids, lipoproteins, and hyperinsulinemia in Watanabe heritable hyperlipidemic rabbits. Curr Ther Res Clin Exp 1997. [DOI: 10.1016/s0011-393x(97)80054-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Zhang B, Saku K, Arakawa K. Quantification of the effects of troglitazone on insulin sensitivity and beta-cell function in Watanabe heritable hyperlipidemic rabbits: a minimal model analysis. Metabolism 1997; 46:273-81. [PMID: 9054469 DOI: 10.1016/s0026-0495(97)90253-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Troglitazone is a newly developed antidiabetic drug that has been shown to improve insulin resistance and hyperinsulinemia both in diabetic animal models and in patients with non-insulin-dependent diabetes mellitus. The Watanabe heritable hyperlipidemic (WHHL) rabbit, an animal model of familial hypercholesterolemia, is characterized by hyperinsulinemia, which reflects insulin resistance. In this study to determine the effects of troglitazone on glucose and insulin metabolism in WHHL rabbits, we quantified the rate of glucose utilization (glucose tolerance index [Kg]), sensitivity of first-phase posthepatic insulin secretion to glucose (phi1), sensitivity of second-phase posthepatic insulin secretion to glucose (phi2), insulin sensitivity to glucose disposal ([Si] inversely related to insulin resistance), insulin-independent glucose disposal (glucose effectiveness [Sg]), and rate of insulin clearance (Ki) by incorporating our previously reported two-compartment model of a glucose/insulin system with the glucose disappearance model of Bergman. Galvin insulin sensitivity (GIS) was also computed for comparison with Bergman Si. When troglitazone was administered as a food admixture (24 mg/d per animal) for 6 months, it did not significantly affect beta-cell function as measured by phi2, glucose tolerance as measured by Kg, or Sg, but increased both Si and Ki and reduced phi1, leading to a decreased plasma insulin response during the intravenous glucose tolerance test (IVGTT). Si was strongly and significantly correlated with GIS. These data indicate that in WHHL rabbits, troglitazone improves insulin sensitivity and posthepatic insulin clearance without affecting beta-cell function or glucose tolerance.
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Affiliation(s)
- B Zhang
- Department of Internal Medicine, Fukuoka University School of Medicine, Japan
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Zhang B, Saku K, Hirata K, Liu R, Tateishi K, Shiomi M, Arakawa K. Quantitative characterization of insulin-glucose response in Watanabe heritable hyperlipidemic and cholesterol-fed rabbits and the effect of cilazapril. Metabolism 1994; 43:360-6. [PMID: 8139485 DOI: 10.1016/0026-0495(94)90105-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A great deal of evidence suggests that insulin resistance, via hyperinsulinemia, contributes to hyperlipoproteinemia and coronary atherosclerosis. When Watanabe heritable hyperlipidemic (WHHL) rabbits, an animal model of familial hypercholesterolemia (FH), are compared with normolipidemic Japanese White (JW) rabbits, an elevated fasting plasma insulin level and a heightened plasma insulin response to an intravenous (i.v.) glucose challenge are found. To elucidate the mechanism behind this phenomenon, a two-compartment model of the glucose/insulin system was fitted to empirical time courses of glucose and insulin concentrations during an i.v. glucose tolerance test (IVGTT) by nonlinear least-square regression, and the model parameters such as the glucose utilization rate constant, insulin degradation rate constant, and pancreas sensitivity were determined. WHHL rabbits showed decreased values of glucose utilization and insulin degradation rate constants and slightly higher values of pancreas sensitivity. This suggests that insulin resistance occurs in extrapancreatic tissues, and that this may be attributable to insulin receptor and/or post-insulin receptor abnormalities. Cholesterol feeding did not significantly change glucose tolerance or insulin action in JW rabbits. The effects of an angiotensin-converting enzyme (ACE) inhibitor, cilazapril, on insulin resistance were also examined in WHHL and JW rabbits. A decreased insulin response to an i.v. glucose challenge and increased glucose utilization and insulin degradation rate constants were observed in WHHL rabbits that had been treated with cilazapril, indicating that cilazapril improved insulin resistance in WHHL rabbits, possibly by increasing the number of insulin receptors. No significant differences were found in glucose tolerance and insulin action in JW rabbits before and after cilazapril administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- B Zhang
- Department of Internal Medicine, Fukuoka University School of Medicine, Japan
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Affiliation(s)
- K E Suckling
- SmithKline Beecham Pharmaceuticals, Welwyn, Herts, U.K
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