目的:本研究通过分析神经源性诱导因子Agrin及其受体-肌特异性受体酪氨酸激酶Mu SK在成长期(离乳-性成熟)骨骼肌的表达水平,探讨其在神经肌肉连接(NMJ)发育中的作用及早期运动干预的影响。方法:出生18天SD雄性大鼠130只随机分为运动组5...目的:本研究通过分析神经源性诱导因子Agrin及其受体-肌特异性受体酪氨酸激酶Mu SK在成长期(离乳-性成熟)骨骼肌的表达水平,探讨其在神经肌肉连接(NMJ)发育中的作用及早期运动干预的影响。方法:出生18天SD雄性大鼠130只随机分为运动组50只、悬吊组和对照组各40只,运动组和悬吊组分别进行运动增强(跑台运动)和运动减弱(尾部悬吊)干预。对照组3周龄时,各组4周龄、5周龄、6周龄、8周龄时分别取材10只。测定并比较正常发育(3~8周龄)及运动干预下腓肠肌Agrin和Mu SKm RNA水平(RT-PCR法)及腓肠肌Mu SK蛋白水平(ELISA法)的差异。结果:(1)对照组的Agrin m RNA在4周龄较3周龄表达减少(P<0.01),5周龄再次出现表达高峰(P<0.01),在4周龄后Mu SK m RNA表达减少(P<0.01),6周龄再次出现Mu SK m RNA表达高峰(P<0.01);运动组Mu SK m RNA表达水平在5周龄时显著高于对照组(P<0.01),而悬吊组Mu SK m RNA表达水平在各周龄均低于对照组(P<0.05,P<0.01)。(2)运动组Mu SK蛋白水平在各周龄组均高于对照组(P<0.05);悬吊组在4周龄时低于对照组(P<0.05)。结论:成长期腓肠肌Agrin及其受体Mu SK的表达具有一定的时间规律,在出生3~4周(离乳前后)呈现逐渐减少的趋势,5~6周(青春期)再次出现表达高峰;在此期间进行适当的运动训练可以促使Agrin及其受体Mu SK表达增多,这可能作为一种机制,促进NMJ在成长期的发育过程。展开更多
To investigate the effects of organophosphorus (OP),carbamate (Carb),pyrehroid (Pyr) insecticides and their mixtures on neuromuscular junction transmission (NMJT),dimethoate(D) and phoxim(P),methomyl(M),and fenvalerat...To investigate the effects of organophosphorus (OP),carbamate (Carb),pyrehroid (Pyr) insecticides and their mixtures on neuromuscular junction transmission (NMJT),dimethoate(D) and phoxim(P),methomyl(M),and fenvalerate(F) were selected.Rats were intraperitoneally intoxicated by D,P,M,F,D+M,D+F,P+M,or P+F with the dosage of each LD50 respectively.The function of the NMJT was assessed with the mean consecutive differences (MCD) of the latencies of single fiber action potentials detected by stimulation single fiber electromyography(SSFEMG) at the stimulus frequency of 20 Hz.The SSFEMG was also applied to detect the function of NMJT in 40 patients with OPs and their mixtures poisoning in this study.The results showed that (1)the myasthenia occurred only in rats with OPs and their mixtures poisoning,but not in F,M intoxicated rats.The increase of MCD shown by SSFEMG and induced by OP and their mixtures indicating a post-synaptic block was well correlated with the occurrence of myasthenia both in rats and patients(P<0.001);(2)the increase of MCD in rats of OP poisoning was significant in comparison with the control and F,M intoxicated rats;but was not significantly different from those in rats intoxicated by OP mixtures;(3)the MCDs were significantly increased in IMS patients of both acute OP poisoning and OP mixtures poisoning,but showing no significant difference between the two groups of patients.It is concluded that OP is the only responsible agent for the dysfunction of neuromuscular transmission induced by single OP and OP mixture insecticides which could be sensitively detected by SSFEMG.展开更多
文摘目的:本研究通过分析神经源性诱导因子Agrin及其受体-肌特异性受体酪氨酸激酶Mu SK在成长期(离乳-性成熟)骨骼肌的表达水平,探讨其在神经肌肉连接(NMJ)发育中的作用及早期运动干预的影响。方法:出生18天SD雄性大鼠130只随机分为运动组50只、悬吊组和对照组各40只,运动组和悬吊组分别进行运动增强(跑台运动)和运动减弱(尾部悬吊)干预。对照组3周龄时,各组4周龄、5周龄、6周龄、8周龄时分别取材10只。测定并比较正常发育(3~8周龄)及运动干预下腓肠肌Agrin和Mu SKm RNA水平(RT-PCR法)及腓肠肌Mu SK蛋白水平(ELISA法)的差异。结果:(1)对照组的Agrin m RNA在4周龄较3周龄表达减少(P<0.01),5周龄再次出现表达高峰(P<0.01),在4周龄后Mu SK m RNA表达减少(P<0.01),6周龄再次出现Mu SK m RNA表达高峰(P<0.01);运动组Mu SK m RNA表达水平在5周龄时显著高于对照组(P<0.01),而悬吊组Mu SK m RNA表达水平在各周龄均低于对照组(P<0.05,P<0.01)。(2)运动组Mu SK蛋白水平在各周龄组均高于对照组(P<0.05);悬吊组在4周龄时低于对照组(P<0.05)。结论:成长期腓肠肌Agrin及其受体Mu SK的表达具有一定的时间规律,在出生3~4周(离乳前后)呈现逐渐减少的趋势,5~6周(青春期)再次出现表达高峰;在此期间进行适当的运动训练可以促使Agrin及其受体Mu SK表达增多,这可能作为一种机制,促进NMJ在成长期的发育过程。
文摘To investigate the effects of organophosphorus (OP),carbamate (Carb),pyrehroid (Pyr) insecticides and their mixtures on neuromuscular junction transmission (NMJT),dimethoate(D) and phoxim(P),methomyl(M),and fenvalerate(F) were selected.Rats were intraperitoneally intoxicated by D,P,M,F,D+M,D+F,P+M,or P+F with the dosage of each LD50 respectively.The function of the NMJT was assessed with the mean consecutive differences (MCD) of the latencies of single fiber action potentials detected by stimulation single fiber electromyography(SSFEMG) at the stimulus frequency of 20 Hz.The SSFEMG was also applied to detect the function of NMJT in 40 patients with OPs and their mixtures poisoning in this study.The results showed that (1)the myasthenia occurred only in rats with OPs and their mixtures poisoning,but not in F,M intoxicated rats.The increase of MCD shown by SSFEMG and induced by OP and their mixtures indicating a post-synaptic block was well correlated with the occurrence of myasthenia both in rats and patients(P<0.001);(2)the increase of MCD in rats of OP poisoning was significant in comparison with the control and F,M intoxicated rats;but was not significantly different from those in rats intoxicated by OP mixtures;(3)the MCDs were significantly increased in IMS patients of both acute OP poisoning and OP mixtures poisoning,but showing no significant difference between the two groups of patients.It is concluded that OP is the only responsible agent for the dysfunction of neuromuscular transmission induced by single OP and OP mixture insecticides which could be sensitively detected by SSFEMG.