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NEP Activity (nep + activity)
Selected AbstractsDiet-induced obesity in Sprague,Dawley rats causes microvascular and neural dysfunctionDIABETES/METABOLISM: RESEARCH AND REVIEWS, Issue 4 2010Eric P. Davidson Abstract 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. Results Rats fed a high fat diet for 32 weeks developed sensory neuropathy, as indicated by slowing of sensory nerve conduction velocity and thermal hypoalgesia. Motor nerve conduction velocity and endoneurial blood flow were not impaired. Mean axonal diameter of myelinated fibres of the sciatic nerve was unchanged in high fat-fed rats compared with that in control. Intraepidermal nerve fibre density was significantly reduced in high fat-fed rats. Vascular relaxation to acetylcholine and calcitonin gene-related peptide was decreased and expression of neutral endopeptidase (NEP) increased in epineurial arterioles of rats fed a high fat diet. In contrast, insulin-mediated vascular relaxation was increased in epineurial arterioles. NEP activity was significantly increased in the skin of the hindpaw. Markers of oxidative stress were increased in the aorta and serum of high fat-fed rats but not in epineurial arterioles. Conclusion Chronic obesity causes microvascular and neural dysfunction. This is associated with increased expression of NEP but not oxidative stress in epineurial arterioles. NEP degrades vasoactive peptides, which may explain the decrease in microvascular function. Copyright © 2010 John Wiley & Sons, Ltd. [source] Possible biphasic changes of free radicals in ethylene glycol-induced nephrolithiasis in ratsBJU INTERNATIONAL, Issue 9 2000H.S. Huang Objective To evaluate the possible role of free radicals in nephrolithiasis in rats induced by ethylene glycol, and to examine the correlation between the urinary enzymes N-acetyl-,-glucosaminidase (NAG), ,-galactosidase (GAL) and neutral endopeptidase (NEP), and free radical production. Materials and methods Hyperoxaluria was produced in male Wistar rats by adding ethylene glycol to their drinking water. After 7, 21 and 42 days of treatment, urinary oxalate, creatinine clearance and urinary enzymes (NAG, GAL and NEP) were measured. The nitroblue tetrazolium perfusion method was used to locate the sites of free-radical production. Ultrasensitive chemiluminescence was used to directly measure the production of reactive oxygen species (ROS) in vivo. Vitamin E and potassium citrate were fed to rats, in addition to ethylene glycol, to assess their effects on free radical production. Results Urinary oxalate increased significantly and was associated with an increase in NAG and GAL at all sample times. However, urinary NEP activity was unchanged on day 7, although there was four times as much NEP on days 21 and 42 than in the control groups. Formazan particles in the renal cortex were scored as 3+ to 4+ in rats treated for 7 days with ethylene glycol. Blood ROS levels were also higher in this group than in the controls (P < 0.01). After vitamin E and potassium citrate treatment, blood ROS levels were lower than in rats treated with ethylene glycol alone. Conclusion Free radicals may be produced in the early stages of nephrolithiasis in rats fed with ethylene glycol. Free radicals occurred mainly in blood and might be associated with NEP inactivation. [source] Retracted: Dynorphin inhibits NEP activity in R1.1 mouse thymoma cellsCELL BIOCHEMISTRY AND FUNCTION, Issue 8 2008Irena Martin-Kleiner The following article from Cell Biochemistry and Function, Dynorphin inhibits NEP activity in R1.1 mouse thymoma cells, by I. Martin-Kleiner, T. Balog and T. Marotti, published online on 21 October 2008 in Wiley InterScience (www.interscience.wiley.com), has been retracted by agreement between the authors, the journal Editor-in-Chief, Nigel Loveridge, and Wiley-Blackwell. The retraction has been agreed due to doubts regarding the reproducibility of the data. Copyright © 2008 John Wiley & Sons, Ltd. [source] |