Font Size: a A A

Effect Of Hyperhomocysteinemia On Structure And Function Of Peripheral Nerve In Rat

Posted on:2009-11-19Degree:MasterType:Thesis
Country:ChinaCandidate:W YuFull Text:PDF
GTID:2144360245484104Subject:Neurology
Abstract/Summary:PDF Full Text Request
Objective:Hyperhomocysteinemia(Hhcy),related to many nervous system diseases, may be an independent risk factor for diabetic peripheral neuropathy(DPN).But there's no report about its inducing peripheral neuropathy until now.The aim of this study was to investigate the effect of Hhcy on structure and function of peripheral nerve and the changes of serum oxidoreduction indexes in rats.Methods:The 20 heathy male Sprague-Dawley rats were randomly divided into 2 groups by weight:Hhcy group(H group,homomethionin feedstuff)and control group(C group,common feedstuff)).We tested plasm total homocysteine(tHcy) levels by high performance liquid chromatography(HPLC)at the end of 0,4th,8th,12th,16th,20th,24th weeks.After 24weeks,we observed the morphologic and ultrastructure changes of sural nerve by Luxol fast blue stain and electron microscope, analyzed the expression of myelin basic protein(MBP)and neurofilament protein (NF)in sural nerve by immunohistochemistry technique,recorded the threshold to nociceptive pain on the 50 degrees C warm water tail withdrawal test,determined the motor and sensory nerve conduction velocity(MCV,SCV)and compound muscle action potential and sensory nerve action potential(CMAP,SNAP)amplitudes of tail nerve with electromyography,measured superoxide dismutase(SOD)vigor, malondialdehyde(MDA)and nitric oxide(NO)levels in blood serum.Statistical significance was assessed with analysis of variance or T-test at P<0.05.Results:1 The concentrations of plasma tHcy in the different times:The tHcy levels of H group rats on the 4th week(19.93±5.20μmol/L)was increased significantly than those on the 0 week(9.33±2.17μmol/L)and those of C group(9.26±1.58μmol/L)in the same time(all P<0.05),the Hhcy models were induced successfully.The tHcy levels of H group rats on the 8th,12th,16th,20th,24th weeks(21.80±4.00μmol/L, 22.77±3.12μmol/L,27.82±5.24μmol/L,31.89±5.65μmol/L,30.64±4.35μmol/L)were still higher significantly than those of C group rats in the same time (9.05±1.91μmol/L,9.10±2.26μmol/L,9.00±1.38μmol/L,9.25±1.56μmol/L, 9.60±2.08μmol/L)(all P<0.05),about 2~3 folds. 2 The morphologic results of sural nerve:In sural nerve of H group rats,the numbers,mean fiber area,mean myelin area and mean axonal area of myelinated fibers in unit area(per mm~2)(15790±1431,21.42±2.09μm~2,11.67±1.89μm~2, 9.31±2.19μm~2)were decreased significantly than those of C group rats(16802±1620, 26.35±1.75μm~2,14.64±1.62μm~2,12.81±4.19μm~2)(all P<0.05).3 The expressions of MBP and NF in sural nerve:The integral optical density of MBP and NF in sural nerve of H group rats(18421.85±2701.73,12644.54±2195.60) were significantly lower than those of C group rats(24960.93±3081.83, 16401.39±2065.12)(all P<0.05).4 Ultrastructure changes of sural nerve:the myelinated lamellae and microorganelles of axoplasm were clearly identified in C group rats.Unmyelinated axons were observed on occasion.There were nerve fiber loss,axonal degeneration, segmental demyelination and interstitial edema in H group rats.Neither pathological changes nor erythrocytes in endoneurial capillaries were found at C group rats,but degeneration in the capillaries was found in H group rats.5 Electrophysiology results and thermal nociceptive thresholds:MCV,SCV, amplitudes of CMAP and SNAP(17.28±1.89m/s,30.69±3.22 m/s,0.30±0.10mv, 4.89±2.00μv)of H group rats were significantly lower than those of C group rats(21.59±2.52m/s,40.20±3.15m/s,0.50±0.17mv,7.81±2.73μv)(all P<0.05). Thresholds to warm water tail withdrawal tests in H group rats(9.10±1.20 s)were significantly longer than those(6.50±2.07 s)in the C group rats(all P<0.05).6 SOD,MDA,NO levels:MDA levels(7.50±1.72nmol/L)of H group rats were significantly higher than those of C group rats(4.08±0.45nmol/L)and SOD vigor(214.21±11.52U/ml)and NO levels(23.59±4.23μmol/L)of H group were significantly lower than those of C group rats(310.30±22.48U/ml,29.40±2.01μmol/L) (all P<0.05).Conclusion:Hhcy can be induced by homomethionin diet and damage the structure and fuction of peripheral nerve in rat,which may be related to oxidative stress.
Keywords/Search Tags:Hyperhomocysteinemia, Rat, Peripheral Nerve, Myelin Basic Protein, Neurofilament Protein, Nerve Conduction Velocity, Oxidative Stress
PDF Full Text Request
Related items