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Coudrillier B, Pijanka J, Jefferys J, Sorensen T, Quigley HA, Boote C, Nguyen TD. Effects of age and diabetes on scleral stiffness. J Biomech Eng 2015; 137:2196535. [PMID: 25751456 DOI: 10.1115/1.4029986] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2014] [Indexed: 02/05/2023]
Abstract
The effects of diabetes on the collagen structure and material properties of the sclera are unknown but may be important to elucidate whether diabetes is a risk factor for major ocular diseases such as glaucoma. This study provides a quantitative assessment of the changes in scleral stiffness and collagen fiber alignment associated with diabetes. Posterior scleral shells from five diabetic donors and seven non-diabetic donors were pressurized to 30 mm Hg. Three-dimensional surface displacements were calculated during inflation testing using digital image correlation (DIC). After testing, each specimen was subjected to wide-angle X-ray scattering (WAXS) measurements of its collagen organization. Specimen-specific finite element models of the posterior scleras were generated from the experimentally measured geometry. An inverse finite element analysis was developed to determine the material properties of the specimens, i.e., matrix and fiber stiffness, by matching DIC-measured and finite element predicted displacement fields. Effects of age and diabetes on the degree of fiber alignment, matrix and collagen fiber stiffness, and mechanical anisotropy were estimated using mixed effects models accounting for spatial autocorrelation. Older age was associated with a lower degree of fiber alignment and larger matrix stiffness for both diabetic and non-diabetic scleras. However, the age-related increase in matrix stiffness was 87% larger in diabetic specimens compared to non-diabetic controls and diabetic scleras had a significantly larger matrix stiffness (p = 0.01). Older age was associated with a nearly significant increase in collagen fiber stiffness for diabetic specimens only (p = 0.06), as well as a decrease in mechanical anisotropy for non-diabetic scleras only (p = 0.04). The interaction between age and diabetes was not significant for all outcomes. This study suggests that the age-related increase in scleral stiffness is accelerated in eyes with diabetes, which may have important implications in glaucoma.
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Quondamatteo F. Skin and diabetes mellitus: what do we know? Cell Tissue Res 2013; 355:1-21. [PMID: 24318789 DOI: 10.1007/s00441-013-1751-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Accepted: 10/29/2013] [Indexed: 12/20/2022]
Abstract
Diabetes mellitus (DM) is becoming increasingly prevalent worldwide. Although major complications of this condition involve kidney, retina and peripheral nerves, the skin of diabetic patients is also frequently injured. Hence, interest is mounting in the definition of the structural and molecular profile of non-complicated diabetic skin, i.e., before injuries occur. Most of the available knowledge in this area has been obtained relatively recently and, in part, derives from various diabetic animal models. These include both insulin-dependent and insulin-resistant models. Structural work in human diabetic skin has also been carried out by means of tissue samples or of non-invasive methods. Indications have indeed been found for molecular/structural changes in diabetic skin. However, the overall picture that emerges is heterogeneous, incomplete and often contradictory and many questions remain unanswered. This review aims to detail, as much as possible, the various pieces of current knowledge in a systematic and synoptic manner. This should aid the identification of areas in which key questions are still open and more research is needed. A comprehensive understanding of this field could help in determining molecular targets for the prevention and treatment of skin injuries in DM and markers for the monitoring of cutaneous and systemic aspects of the disease. Additionally, with the increasing development of non-invasive optics-based deep-tissue-imaging diagnostic technologies, precise knowledge of cutaneous texture and molecular structure becomes an important pre-requisite for the use of such methods in diabetic patients.
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Affiliation(s)
- Fabio Quondamatteo
- Skin and ECM Research Group-Anatomy, NUI Galway, Anatomy Building, University Road, Galway, Ireland,
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Rincon-Choles H, Abboud HE, Lee S, Shade RE, Rice KS, Carey KD, Comuzzie AG, Barnes JL. Renal histopathology of a baboon model with type 2 diabetes. Toxicol Pathol 2012; 40:1020-30. [PMID: 22552392 DOI: 10.1177/0192623312444025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Naturally occurring type 2 diabetes has been found in a colony of baboons. Ongoing characterization of the baboon colony maintained at the Southwest National Primate Research Center has revealed a significant range of glucose sensitivity with some animals clearly diabetic. Seven baboons, four with diabetes and three without diabetes, underwent histopathological investigation. Three diabetic animals were diagnosed using fasting blood glucose, hemoglobin A1C, and intravenous glucose tolerance test, and a fourth one was known to have hyperglycemia. One control baboon and three baboons with diabetes had microalbuminuria. On kidney biopsy, diabetic baboons had thickening of the glomerular basement membrane and mesangial matrix expansion compared to controls. Immunohistochemistry showed the diabetic animals had increased mesangial expression of cellular fibronectin ED-A. Two diabetic animals with microalbuminuria had evidence of mesangiolysis with the formation of an early nodule. One diabetic animal had a Kimmestiel-Wilson nodule. We conclude that the baboon represents a useful primate model of diabetes and nephropathy that resembles the nephropathy associated with type 2 diabetes in humans.
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Affiliation(s)
- Hernan Rincon-Choles
- Audie L Murphy Division, South Texas Veterans Health Care System, San Antonio, Texas, USA
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Kanter M. Protective effects of thymoquinone on streptozotocin-induced diabetic nephropathy. J Mol Histol 2009; 40:107-15. [PMID: 19484499 DOI: 10.1007/s10735-009-9220-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Accepted: 05/18/2009] [Indexed: 01/15/2023]
Abstract
The aim of this study was designed to investigate the possible beneficial effects of the thymoquinone (TQ) in streptozotocine (STZ)-induced diabetes in rats. The rats were randomly allotted into one of three experimental groups: A (control), B (diabetic untreated), and C (diabetic treated with TQ); each group contain ten animals. B and C groups received STZ. Diabetes was induced in two groups by a single intra-peritoneal (i.p) injection of STZ (50 mg/kg, freshly dissolved in 5 mmol/l citrate buffer, pH 4.5). Two days after STZ treatment, development of diabetes in two experimental groups was confirmed by measuring blood glucose levels in a tail vein blood samples. Rats with blood glucose levels of 250 mg/dl or higher were considered to be diabetic. The rats in TQ treated groups were given TQ (50 mg/kg body weight) once a day orally by using intra gastric intubation for 12 weeks starting 2 days after STZ injection. Treatment of TQ reduced the glomerular size, thickening of capsular, glomerular and tubular basement membranes, increased amounts of mesangial matrix and tubular dilatation and renal function as compared with diabetics untreated. We conclude that TQ therapy causes renal morphologic and functional improvement after STZ-induced diabetes in rats. We believe that further preclinical research into the utility of TQ treatment may indicate its usefulness as a potential treatment in diabetic nephropathy.
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Affiliation(s)
- Mehmet Kanter
- Department of Histology and Embryology, Faculty of Medicine, Trakya University, 22030 Edirne, Turkey.
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Brooks BA, Heffernan S, Thomson S, McLennan SV, Twigg SM, Yue DK. The effects of diabetes and aminoguanidine treatment on endothelial function in a primate model of type 1 diabetes. Am J Primatol 2008; 70:796-802. [DOI: 10.1002/ajp.20550] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Thomson SE, McLennan SV, Kirwan PD, Heffernan SJ, Hennessy A, Yue DK, Twigg SM. Renal connective tissue growth factor correlates with glomerular basement membrane thickness and prospective albuminuria in a non-human primate model of diabetes: possible predictive marker for incipient diabetic nephropathy. J Diabetes Complications 2008; 22:284-94. [PMID: 18413184 DOI: 10.1016/j.jdiacomp.2007.07.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 06/05/2007] [Accepted: 07/10/2007] [Indexed: 01/31/2023]
Abstract
UNLABELLED Diabetic renal disease is characterized by accumulation of extracellular matrix, glomerulosclerosis, and tubulointerstitial fibrosis. Connective tissue growth factor (CTGF) is implicated in these changes, as it contributes to new matrix synthesis and is increased in the diabetic kidney. CTGF also inhibits mesangial matrix degradation through up-regulation of the tissue inhibitor of matrix metalloproteinase 1 (TIMP-1). In a non-human primate model of diabetes, we determined whether the level of renal CTGF protein before development of albuminuria correlated with renal matrix and TIMP-1 changes and whether renal CTGF predicts progression to albuminuria. METHODS In a group of diabetic (n=9) and control (n=6) baboons after a 5-year duration of diabetes, renal tissue CTGF and TIMP-1 were detected by immunohistochemistry and compared with glomerular basement membrane (GBM) thickness and mesangial volume measurements from electron photomicrographs of renal biopsies. Urinary albumin levels were measured at 5 and 10 years of diabetes. RESULTS GBM thickness, CTGF protein, and TIMP-1 protein were increased after 5 years of diabetes (each P<.05). Tubular fibronectin scores correlated with tubular CTGF scores (r=0.72, P=.002). In diabetic animals, GBM thickness correlated with tubular and total CTGF levels (P=.002 and P=.04, respectively), whereas mesangial cell and total matrix volume correlated with glomerular TIMP-1 (P=.02 and P=.01, respectively). Tubular CTGF scores (P=.008) and GBM thickness (P=.03) at 5 years in diabetes each predicted the degree of albuminuria at 10 years. CONCLUSIONS These results suggest that early increases in renal CTGF protein contribute to incipient diabetic nephropathy and that renal CTGF may have utility as an early marker for progression to dysfunction in the diabetic kidney.
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Affiliation(s)
- Sally E Thomson
- Discipline of Medicine, University of Sydney, Sydney, Australia
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Jamieson HA, Cogger VC, Twigg SM, McLennan SV, Warren A, Cheluvappa R, Hilmer SN, Fraser R, de Cabo R, Le Couteur DG. Alterations in liver sinusoidal endothelium in a baboon model of type 1 diabetes. Diabetologia 2007; 50:1969-1976. [PMID: 17604976 DOI: 10.1007/s00125-007-0739-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 05/28/2007] [Indexed: 02/06/2023]
Abstract
AIMS/HYPOTHESIS Diabetes mellitus is associated with extensive vascular pathology, yet little is known about its long-term effects on liver sinusoidal endothelial cells (LSECs). Potential diabetic changes in LSECs are important because of the role played by fenestrations in the LSECs in hepatic disposition of lipoproteins. MATERIALS AND METHODS Surgical liver biopsies for electron microscopy and immunohistochemistry were obtained from baboons with long-standing streptozotocin-induced, insulin-treated diabetes mellitus and compared with those from age-matched control animals. RESULTS There was an increase in the thickness of LSECs (170 +/- 17 vs 123 +/- 10 nm, p < 0.01). Fenestrations in LSECs, as determined by overall porosity, were markedly reduced (1.4 +/- 0.1% vs 2.6 +/- 0.2%, p < 0.01). Increased numbers of stellate cells were seen on electron microscopy, and this finding was corroborated by increased smooth muscle actin expression. Diabetes mellitus was also associated with increased endothelial production of von Willebrand factor and caveolin-1. CONCLUSIONS/INTERPRETATION Diabetes mellitus in the non-human primate is associated with marked changes in LSECs, including a reduction in fenestrations. Such changes provide an additional and novel mechanism for impaired hepatic lipoprotein clearance and post-prandial hyperlipidaemia in diabetes mellitus.
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Affiliation(s)
- H A Jamieson
- Centre for Education and Research on Ageing, Concord Hospital, Sydney, NSW, Australia.
- ANZAC Research Institute, Concord RG Hospital and University of Sydney, Concord, NSW, 2139, Australia.
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA.
| | - V C Cogger
- Centre for Education and Research on Ageing, Concord Hospital, Sydney, NSW, Australia
- ANZAC Research Institute, Concord RG Hospital and University of Sydney, Concord, NSW, 2139, Australia
| | - S M Twigg
- Department of Endocrinology, Royal Prince Alfred Hospital and University of Sydney, Camperdown, NSW, Australia
| | - S V McLennan
- Department of Endocrinology, Royal Prince Alfred Hospital and University of Sydney, Camperdown, NSW, Australia
| | - A Warren
- Centre for Education and Research on Ageing, Concord Hospital, Sydney, NSW, Australia
- ANZAC Research Institute, Concord RG Hospital and University of Sydney, Concord, NSW, 2139, Australia
| | - R Cheluvappa
- Centre for Education and Research on Ageing, Concord Hospital, Sydney, NSW, Australia
- ANZAC Research Institute, Concord RG Hospital and University of Sydney, Concord, NSW, 2139, Australia
| | - S N Hilmer
- Centre for Education and Research on Ageing, Concord Hospital, Sydney, NSW, Australia
- Department of Aged Care, Royal North Shore Hospital, St Leonards, NSW, Australia
- Department of Clinical Pharmacology, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - R Fraser
- Department of Pathology, Christchurch School of Medicine, University of Otago, Christchurch, New Zealand
| | - R de Cabo
- Laboratory of Experimental Gerontology, National Institute on Aging, National Institutes of Health, Baltimore, MD, USA
| | - D G Le Couteur
- Centre for Education and Research on Ageing, Concord Hospital, Sydney, NSW, Australia
- ANZAC Research Institute, Concord RG Hospital and University of Sydney, Concord, NSW, 2139, Australia
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Patel A, Barzi F, Jamrozik K, Lam TH, Ueshima H, Whitlock G, Woodward M. Serum triglycerides as a risk factor for cardiovascular diseases in the Asia-Pacific region. Circulation 2004; 110:2678-86. [PMID: 15492305 DOI: 10.1161/01.cir.0000145615.33955.83] [Citation(s) in RCA: 220] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The importance of serum triglyceride levels as a risk factor for cardiovascular diseases is uncertain. METHODS AND RESULTS We performed an individual participant data meta-analysis of prospective studies conducted in the Asia-Pacific region. Cox models were applied to the combined data from 26 studies to estimate the overall and region-, sex-, and age-specific hazard ratios for major cardiovascular diseases by fifths of triglyceride values. During 796,671 person-years of follow-up among 96,224 individuals, 670 and 667 deaths as a result of coronary heart disease (CHD) and stroke, respectively, were recorded. After adjustment for major cardiovascular risk factors, participants grouped in the highest fifth of triglyceride levels had a 70% (95% CI, 47 to 96) greater risk of CHD death, an 80% (95% CI, 49 to 119) higher risk of fatal or nonfatal CHD, and a 50% (95% CI, 29% to 76%) increased risk of fatal or nonfatal stroke compared with those belonging to the lowest fifth. The association between triglycerides and CHD death was similar across subgroups defined by ethnicity, age, and sex. CONCLUSIONS Serum triglycerides are an important and independent predictor of CHD and stroke risk in the Asia-Pacific region. These results may have clinical implications for cardiovascular risk prediction and the use of lipid-lowering therapy.
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Affiliation(s)
- A Patel
- Asia-Pacific Cohort Studies Collaboration Secretariat, The George Institute for International Health, University of Sydney, PO Box M201, Missenden Rd, Camperdown, Sydney NSW 2050, Australia.
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Erensoy N, Yilmazer S, Oztürk M, Tunçdemir M, Uysal O, Hatemi H. Effects of ACE inhibition on the expression of type IV collagen and laminin in renal glomeruli in experimental diabetes. Acta Histochem 2004; 106:279-87. [PMID: 15350810 DOI: 10.1016/j.acthis.2004.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2003] [Revised: 04/01/2004] [Accepted: 04/02/2004] [Indexed: 11/17/2022]
Abstract
In the present study, we examined electron microscopically and immunohistochemically the effects of perindopril, an angiotensin-converting enzyme inhibitor, on renal microangiopathy in streptozotocin-induced diabetes in rats. To investigate changes in glomerular basement membrane (GBM) and tubular basement membrane components, we immunohistochemically localized type IV collagen and laminin. Animals have been divided into three groups of eight adult male rats each. The first group was the non-diabetic control group. The second group consisted of untreated diabetic rats. The third group consisted of diabetic rats that were treated with perindopril for 6 weeks. Blood glucose levels and body weight were measured. Morphometric analysis of kidney tissue was performed using light and electron microscopy to quantify glomerular size and thickness of the GBM. Blood glucose levels in diabetic rats were significantly increased when compared with non-diabetic controls. Blood glucose levels were not affected by perindopril treatment. Untreated diabetic rats showed increased glomerular size, thickening of the GBM and an increase in mesangial matrix as compared with controls. Treatment with perindopril prevented effectively glomerular hypertrophy and thickening of the GBM. Significant increase in type IV collagen and laminin was found in thickened GBM and mesangial matrix in kidneys of untreated diabetic rats. In perindopril-treated diabetic rats, staining of type IV collagen and laminin was less strong when compared with untreated diabetic rats. In conclusion, our data suggest that perindopril treatment is effective in preventing renal lesions possibly by ameliorating the diabetes-induced increase in expression of type IV collagen and laminin.
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Affiliation(s)
- Nevin Erensoy
- Institute of Experimental Medical Research, University of Istanbul, Istanbul, Turkey
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Cogger VC, Warren A, Fraser R, Ngu M, McLean AJ, Le Couteur DG. Hepatic sinusoidal pseudocapillarization with aging in the non-human primate. Exp Gerontol 2004; 38:1101-7. [PMID: 14580863 DOI: 10.1016/j.exger.2003.07.002] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND/AIMS Age-related changes in the hepatic sinusoid termed pseudocapillarization have been reported in the rat and human and have implications for disease susceptibility in old age. In this study, we investigated whether similar changes occur in the livers of old baboons and thus represent a widespread aging change. METHODS Liver tissue from five young baboons (5.4+/-0.5yrs) and five old baboons (21.8+/-0.7yrs) was compared by transmission electron microscopy, scanning electron microscopy and immunohistochemistry. RESULTS The thickness of the sinusoidal endothelium was increased in old baboons (130+/-8 nm versus 186+/-9 nm, P<0.001) and the frequency of endothelial fenestrae decreased, with the porosity declining from 4.2+/-0.5% to 2.4+/-0.4% (P=0.006). The expression of laminin and von Willebrands factor was more extensive in old baboons. Novel perisinusoidal ring-shaped cells, probably fat-engorged stellate cells, were prominent in the old baboons. CONCLUSIONS Pseudocapillarization is a significant age-related change in the baboon liver. Aging in baboons is associated with a novel aging change in the stellate cell not reported in other species. Hepatic pseudocapillarization is a widespread aging liver change found in several species including humans and other non-human primates.
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Affiliation(s)
- Victoria C Cogger
- Centre for Education and Research on Ageing and ANZAC Research Institute, University of Sydney, Concord RG Hospital, Sydney, NSW 2139, Australia.
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Birrell AM, Heffernan SJ, Kirwan P, McLennan S, Gillin AG, Yue DK. The effects of aminoguanidine on renal changes in a baboon model of Type 1 diabetes. J Diabetes Complications 2002; 16:301-9. [PMID: 12126789 DOI: 10.1016/s1056-8727(01)00225-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND The efficacy of aminoguanidine (AG) on primary prevention of diabetic nephropathy was investigated in a nonhuman primate model of Type 1 diabetes over a period of 4 years. METHODS Adolescent male baboons (Papio hamadryas) were assigned to four groups: control, diabetic, and control and diabetic treated with AG. Diabetes was induced with streptozocin (60 mg/kg) and treated with insulin to maintain a mean HbA1c level of about 9%. AG was given subcutaneously (10 mg/kg) each day. All animals had annual renal biopsies and 24-h urine collections for measurements of glomerular basement membrane (GBM) thickness, fractional mesangium volume (FMV), albumin excretion rate (AER), and creatinine clearance. Glomerular filtration rate (GFR) and renal plasma flow (RPF) were also determined. RESULT The diabetic animals had increased GBM after 2 years of diabetes, but there was no increase in FMV over the study period. AG prevented the thickening of GBM at the 3- and 4-year time points. AG and diabetes synergistically increased the GFR. All diabetic animals developed increased albuminuria during the study although lower than the conventionally accepted microalbuminuria range. AG was not able to prevent this and, in fact, led to the nondiabetic animals also developing albuminuria. CONCLUSION This is the first study to investigate the early use of AG in ameliorating renal damage in a primate model of Type 1 diabetes. The structural and functional changes in the kidney of these animals resemble those seen in the early stages of the human disease. AG was able to significantly reduce the thickening of GBM due to diabetes. This may suggest a potential role for this in primary prevention of diabetic nephropathy in the future.
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Affiliation(s)
- Alex M Birrell
- Department of Renal Medicine, Royal Prince Alfred Hospital, Sydney, Australia
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Premawardhana U, Adams MR, Birrell A, Yue DK, Celermajer DS. Cardiovascular structure and function in baboons with Type 1 diabetes -- a transvenous ultrasound study. J Diabetes Complications 2001; 15:174-80. [PMID: 11457668 DOI: 10.1016/s1056-8727(01)00157-x] [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: 12/24/2022]
Abstract
Diabetes mellitus is an important risk factor for both macrovascular and cardiac disease in humans. The availability of a novel intravenous ultrasound probe allows detailed interrogation of a large proportion of the vasculature, as well as the heart, during the same examination. Six male baboons (Papio hamadryas) with Type 1 diabetes and known microangiopathy, and six control animals were studied. Vascular structure in the major large arteries and cardiac function were studied using transvenous ultrasound introduced via the right femoral vein and positioned under fluoroscopy. All arteries were examined for atherosclerotic plaque and for presence of increased intima-media thickness (IMT). Left ventricular function was assessed at rest and following infusions of dobutamine (positive inotrope) and esmolol (negative inotrope). The procedure was performed safely and successfully in all cases. No atherosclerotic plaque was seen in either diabetic or normal baboons. There was no difference in the aortic IMT (0.38+/-0.04 vs. 0.37+/-0.05 mm, normal vs. diabetic, P=NS) or in doppler flow in the renal or iliac arteries between diabetic and normal baboons. Left ventricular wall thickness and systolic tissue velocity were similar in the two groups at rest (6.9+/-2.5 vs. 6.2+/-1.4 cm/s, normal vs. diabetic, P=NS), after dobutamine (15.5+/-2.2 vs. 12.7+/-3.9 cm/s, normal vs. diabetic, P=NS), and after esmolol (4.3+/-1.0 vs. 5.6+/-1.0 cm/s, normal vs. diabetic, P=NS). In a high primate model of diabetes with microangiopathy, the presence of hyperglycemia for 7 years per se does not produce abnormalities of macrovascular or cardiac structure.
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Affiliation(s)
- U Premawardhana
- The Department of Cardiology, Royal Prince Alfred Hospital, University of Sydney, Camperdown, Sydney, Australia
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