Publications by authors named "Eric P Davidson"

In this study, we wanted to extend our investigation of the efficacy of fish oil with or without salsalate on vascular and neural complications using a type 2 diabetic rat model. Four weeks after the onset of hyperglycemia, diabetic rats were treated via the diet with 3 different amounts of menhaden oil with or without salsalate for 12 weeks. Afterwards, vascular reactivity of epineurial arterioles and neuropathy-related endpoints were examined.

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Previously, we had shown that a vasopeptidase inhibitor drug containing ACE and neprilysin inhibitors was an effective treatment for diabetic vascular and neural complications. However, side effects prevented further development. This led to the development of sacubitril/valsartan, a drug containing angiotensin II receptor blocker and neprilysin inhibitor that we hypothesized would be an effective treatment for diabetic peripheral neuropathy.

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Aims/introduction: Peripheral neuropathy is a common complication of diabetes and also occurs in 30% of human obese individuals with impaired glucose tolerance. Even though peripheral neuropathy affects both sexes, most pre-clinical studies have been carried out using male rodents. The aim of the present study was to create diet-induced obesity and type 2 diabetes in female rats and mice in order to examine the development of peripheral neuropathy.

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Purpose: This study investigated the efficacy of monotherapy versus combination of menhaden oil, α-lipoic acid, and enalapril on corneal sensation and morphometry and other neuropathy-related endpoints in a rat model of type 2 diabetes.

Methods: Male Sprague-Dawley rats (aged 12 weeks) were fed a high-fat diet for 8 weeks followed by 30 mg/kg streptozotocin. After 16 weeks of hyperglycemia, 12-week treatments consisting of menhaden oil, α-lipoic acid, enalapril, or their combination were initiated.

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Article Synopsis
  • The study addresses peripheral neuropathy (PN) in diabetic patients, highlighting the challenges of diagnosis and presenting a new, simpler screening method based on corneal nerve sensitivity.
  • Researchers tested this method on rats using hyperosmolar eye drops and found a correlation between corneal squinting response and neuropathy severity.
  • Results indicate that measuring corneal sensitivity could offer a practical alternative for early PN detection in clinical settings.
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We have previously demonstrated that treating diabetic rats with enalapril, an angiotensin converting enzyme (ACE) inhibitor, α-lipoic acid, an antioxidant, or menhaden oil, a natural source of omega-3 fatty acids can partially improve diabetic peripheral neuropathy. In this study we sought to determine the efficacy of combining these three treatments on vascular and neural complications in a high fat fed low dose streptozotocin treated rat, a model of type 2 diabetes. Rats were fed a high fat diet for 8 weeks followed by a 30 mg/kg dose of streptozotocin.

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We examined whether reversal of high fat diet, stimulating weight loss, compared to two treatments previously shown to have beneficial effects, could improve glucose utilization and peripheral neuropathy in animal models of obesity and type 2 diabetes. Rats were fed a high fat diet and treated with a low dose of streptozotocin to create models of diet induced obesity or type 2 diabetes, respectively. Afterwards, rats were transferred to a normal diet or treated with enalapril or dietary enrichment with menhaden oil for 12 weeks.

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The purpose of this study was to determine the effect of supplementing the diet of type 1 diabetic rats with menhaden oil on diabetic neuropathy. Menhaden oil is a natural source for n-3 fatty acids, which have been shown to have beneficial effects in cardiovascular disease and other morbidities. Streptozotocin-induced diabetic rats were used to examine the influence of supplementing their diet with 25% menhaden oil on diabetic neuropathy.

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Recently a new rat model for type 2 diabetes the Zucker diabetic Sprague-Dawley (ZDSD/Pco) was created. In this study we sought to characterize the development of diabetic neuropathy in ZDSD rats using age-matched Sprague-Dawley rats as a control. Rats were examined at 34 weeks of age 12 weeks after the onset of hyperglycemia in ZDSD rats.

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Purpose: Peripheral neuropathy has been shown to exist in prediabetic and diabetic patients and animal models. However, the development of peripheral neuropathy in prediabetes and posthyperglycemia is likely different. The purpose of this study was to examine the progression of peripheral neuropathy in diet-induced obese rats and high-fat-fed rats treated with a low dose of streptozotocin, a model for type 2 diabetes, using standard endpoints as well as corneal sensitivity and innervation.

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Purpose: Cornea confocal microscopy is emerging as a clinical tool to evaluate the development and progression of diabetic neuropathy. The purpose of these studies was to characterize the early changes in corneal sensitivity and innervation in a rat model of type 1 diabetes in relation to standard peripheral neuropathy endpoints and to assess the effect of Ilepatril, a vasopeptidase inhibitor which blocks angiotensin converting enzyme and neutral endopeptidase, on these endpoints.

Methods: Streptozotocin-diabetic rats 8 weeks duration were treated with or without Ilepatril for the last 6 weeks of the experimental period.

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Aims. To determine the effect of partial replacement of a high-fat diet with menhaden oil on diabetic neuropathy in an animal model of type 2 diabetes. Materials and Methods.

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Purpose: Corneal confocal microscopy is emerging as a clinical tool to evaluate the development and progression of diabetic neuropathy. The purpose of these studies was to characterize the changes in corneal sensitivity and innervation in a rat model of type 2 diabetes in relation to standard peripheral neuropathy endpoints. Assessment of diabetes-induced changes in corneal innervation and sensitivity in animal models will be important for determining the usefulness of corneal markers for preclinical studies to test potential new treatments for diabetic neuropathy.

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Treating high fat fed/low dose streptozotocin-diabetic rats; model of type 2 diabetes, with ilepatril (vasopeptidase inhibitor, blocks neutral endopeptidase (NEP) and angiotensin converting enzyme (ACE)) improved vascular and neural functions. Next, studies were performed to determine the individual effect of inhibition of NEP and ACE on diabetes-induced vascular and neural dysfunctions. High fat fed rats (8 weeks) were treated with 30 mg/kg streptozotocin (i.

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We sought to determine the effect of dipeptidyl peptidase IV (DPP-IV) inhibition on streptozotocin diabetes-induced vascular and neural dysfunction. After 4 weeks of untreated diabetes, rats were treated for 12 weeks with Alogliptin (DPP-IV inhibitor). Diabetes caused a slowing of motor and sensory nerve conduction velocity, thermal hypoalgesia, reduction in intraepidermal nerve fiber density in the hindpaw, and impairment in vascular relaxation to acetylcholine and calcitonin gene-related peptide in epineurial arterioles.

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We have previously shown that treating streptozotocin-induced diabetic rats, an animal model of type 1 diabetes, with Ilepatril (an inhibitor of neutral endopeptidase and angiotensin converting enzyme (ACE)) improves vascular and neural functions. In this study we sought to determine the effect of Ilepatril treatment of high fat fed/low dose streptozotocin-diabetic rats, a model for type 2 diabetes, on vascular and neural complications. Following 8 weeks on a high fat diet rats were treated with 30 mg/kg streptozotocin (i.

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We have previously shown that treating streptozotocin-induced diabetic rats, an animal model of type 1 diabetes, with Ilepatril (an inhibitor of neutral endopeptidase and angiotensin converting enzyme (ACE)) improves vascular and neural function. In this study we sought to determine the individual effect of inhibition of neutral endopeptidase and ACE on diabetes-induced vascular and neural dysfunction. After 4 weeks of untreated diabetes, rats were treated for 12 weeks with Ilepatril, Enalapril (ACE inhibitor) or Candoxatril (neutral endopeptidase inhibitor) followed by analysis of neural and vascular function.

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The objective of this study was to determine the effect of AVE7688, a drug that inhibits both angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP) activity, on neural and vascular defects caused by diet induced obesity (DIO). Rats at 12 weeks of age were fed a standard or high fat diet with or without AVE7688 for 24 weeks. DIO rats had impaired glucose tolerance and developed sensory neuropathy.

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Background: The objective of this study was to determine the effect of diet-induced obesity (DIO) on microvascular and neural function.

Methods: Rats were fed a standard or high fat diet for up to 32 weeks. The following measurements were carried out: vasodilation in epineurial arterioles using videomicroscopy, endoneurial blood flow using hydrogen clearance, nerve conduction velocity using electrical stimulation, size-frequency distribution of myelinated fibres of the sciatic nerve, intraepidermal nerve fibre density using confocal microscopy and thermal nociception using the Hargreaves method.

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The purpose of this study was to determine whether AVE7688 a drug that inhibits both angiotensin converting enzyme and neutral endopeptidase activity protects vascular and nerve functions in an animal model of metabolic syndrome. Obese Zucker rats at 20 weeks of age were treated for 12 weeks with AVE7688. Vasodilation in epineurial arterioles was measured by videomicroscopy and nerve conduction velocity was measured following electrical stimulation.

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Objective: Obese Zucker rats, animal model for the metabolic syndrome, develop a diabetes-like neuropathy that is independent of hyperglycemia. The purpose of this study was to determine whether drugs used to treat cardiovascular dysfunction in metabolic syndrome also protect nerve function.

Methods And Procedures: Obese Zucker rats at 20 weeks of age were treated for 12 weeks with enalapril or rosuvastatin.

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Unlabelled: Our previous studies have shown vascular dysfunction in small coronary and mesenteric arteries in Zucker obese rats, a model of the metabolic syndrome, and Zucker Diabetic Fatty (ZDF) rats, a model of type 2 diabetes. Because of their lipid lowering action and antioxidant activity, we predicted that treatment with Rosuvastatin, an HMG-CoA reductase inhibitor (statin) or Enalapril, an angiotensin converting enzyme (ACE) inhibitor would improve vascular dysfunction associated with the metabolic syndrome and type 2 diabetes.

Methods: 20-week-old Zucker obese and 16-week-old ZDF rats were treated with Rosuvastatin (25 mg/kg/day) or Enalapril (20 mg/kg/day) for 12 weeks.

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In epineurial arterioles, acetylcholine-mediated vascular relaxation is mediated by nitric oxide and endothelium-derived hyperpolarizing factor (EDHF), and both mechanisms are impaired by diabetes. The mediator responsible for the effect of EDHF is unknown. In epineurial arterioles, C-type natriuretic peptide (CNP) has properties consistent with EDHF-like activity.

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We investigated the progression of vascular dysfunction associated with the metabolic syndrome with and without hyperglycemia in lean, Zucker obese, and Zucker diabetic fatty (ZDF) rats. Responses of aorta and small coronary and mesenteric arteries were measured to endothelium-dependent and -independent vasodilators. Indices of oxidative stress were increased in serum from ZDF rats throughout the study, whereas values were increased in Zucker obese rats later in the study [thiobarbituric acid reactive substances: 0.

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ACE inhibition and/or blocking of the angiotensin II receptor are recognized as first-line treatment for nephropathy and cardiovascular disease in diabetic patients. However, little information is available about the potential benefits of these drugs on diabetic neuropathy. We examined vascular and neural activity in streptozotocin-induced diabetic rats that were treated for 12 weeks with enalapril, an ACE inhibitor, or L-158809, an angiotensin II receptor blocker.

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