AIM: To investigate the association of the inducible ni- tric oxide synthetase (iNOS) C150T polymorphism with Helicobacter pylori (H. pylor/) infection and gastric can- cer (GC) risk in Iran. METHODS: In order...AIM: To investigate the association of the inducible ni- tric oxide synthetase (iNOS) C150T polymorphism with Helicobacter pylori (H. pylor/) infection and gastric can- cer (GC) risk in Iran. METHODS: In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T ilVOS poly- morphism was genotyped by polymerase chain reaction (PCR) and restriction digestion. Patients were grouped by cancer presence, demographic and behavior charac- teristics, and/-/, pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS: In this population, we found that smok- ing, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development (P = 0.015, P 〈 0.001, P = 0.0034, and P 〈 0.015, respectively). The distribution of the C150T ilVOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-/-/, pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio (OR) = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC (OR = 5.0, P = 0.029). In contrast, this association was not seen in patients in the control group.CONCLUSION: ACT or TT polymorphism at position 150 in the iNO$ gene significantly increases the risk of GC and may be a marker for GC susceptibility.展开更多
The aim of this study was to determine the immunoreactivity of neuronal and inducible nitric oxide synthetase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase in different regions of brain ...The aim of this study was to determine the immunoreactivity of neuronal and inducible nitric oxide synthetase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase in different regions of brain in rats of kainic acid mediated epilepsy. Male Sprague-Dawley rats were used in this study. The acute group animals were sacrificed after 2 hours and the chronic group animals were sacrificed after 5 days of a single subcutaneous injection of kainic acid (15 mg/kg body weight). The cerebral cortex, cerebellum and brain stem slices were fixed and immunohistostained for the above enzymes. Images were captured and analyzed. In acute group, argininosuccinate synthetase and inducible nitric oxide synthetase were increased in cerebral cortex and cerebellum, neuronal nitric oxide synthetase increased in cerebral cortex and brain stem, and there was no change in argininosuccinate lyase immunoreactivity compared to control group. In chronic group, glutamine synthetase was decreased and all other enzymes immunoreactivity was increased in all the brain regions tested. This study demonstrated the up-regulation of citrul-line-nitric oxide cycle enzymes and may contribute to enhancing recycling of citrulline to arginine to support the increased production of nitric oxide in epilepsy. The decreased glutamine synthetase may increase glutamate in chronic epilepsy and may lead to neurodegeneration.展开更多
Objective To observe the expression of nitric oxide syhthetase(NOS) in hippocampus CA1 neurons with hyperglycemia.Method NADPH d histochemical method was used.Rcsults NOS positive neurons expressed in hippocampus CA1 ...Objective To observe the expression of nitric oxide syhthetase(NOS) in hippocampus CA1 neurons with hyperglycemia.Method NADPH d histochemical method was used.Rcsults NOS positive neurons expressed in hippocampus CA1 and nomal neurons of 6 weeks old rats with hyperglycemia(DM) and normal rats(NC).There was significant difference in neurons between DM group and control group.Conclusion NOS positive neurons decrease in hippocampus CA1 of rats with hyperglycemia.展开更多
NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation, neurotransmission and immunological process. This review will focus...NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation, neurotransmission and immunological process. This review will focus on the nitric oxide synthase gene family and recent progress on molecular genetic analysis of NOS1, NOS2 and N0S3 genes.展开更多
Stavudine, a potent anti HIV and AIDS related complex, is one of the Nucleoside Analogue Reverse Transcriptase Inhibitors (NARTIs). It is phosphorylated intracellularly and then inhibits the viral reverse transcript...Stavudine, a potent anti HIV and AIDS related complex, is one of the Nucleoside Analogue Reverse Transcriptase Inhibitors (NARTIs). It is phosphorylated intracellularly and then inhibits the viral reverse transcriptase by acting as a false substrate. Modifications made on the hydrogen labile at the 5' position on the sugar is an interesting template for the elaboration of new potent anti HIV and AIDS drugs. The expected advantages of the modified stavudine prodrugs can be multiple: synergistic drug activities, enhancement of stavudine intracellular uptake, increase of stavudine brain delivery, and bypass of the first stavudine phosphorylation step into the cells. Nitric oxide synthase inhibitors of stavudine and nitric oxide donors of stavudine may hold significant promise for the treatment of HIV and AIDS.展开更多
Objective: Functional significance of NO and central inhibitory neurotransmitter γ-aminobutyric(GABA) during seizures were investigated morphorlogically. Methods: A kainate-induced complex partialseizure model was us...Objective: Functional significance of NO and central inhibitory neurotransmitter γ-aminobutyric(GABA) during seizures were investigated morphorlogically. Methods: A kainate-induced complex partialseizure model was used in our experiment. Twenty SD rats were randomly divided into KA 30, 60, 90, 200min and control groups. The brain sections were stained by NADPh (nicotinamide adenine dinucleotide phosphate ) diaphorase (Nd ) histochemically, and were further stained by GABA immunohistochemically.Results: Histological and immunohistochemical study revealed that in KA groups the number of Nd and GABA-positive double labelled neurons in CA3 region, CA3 region and dentate gyms was significantly reduced,compared with the control group. Conclusion: Nd coexisted with GABA in the brain. Reduction of GABA release led to relief of GABA-ergic inhibition and in the same way, reduction of NO release weakened its negative feedback modulation. Therefore neuronal synchronous paroxysmal discharges increased. GABA and NO,both having antiepileptic action, acted through different ways or different link in the same way. NO may involve in the effect of GABA-ergic neurons and play cooperative antiepileptic action with GABA.展开更多
Meretrix meretrix Linnaeus has long been used as traditional Chinese medicine in oriental medicine.The angiogentic activity of the extract of M.meretrix was investigated in this study,using human umbilical vein endoth...Meretrix meretrix Linnaeus has long been used as traditional Chinese medicine in oriental medicine.The angiogentic activity of the extract of M.meretrix was investigated in this study,using human umbilical vein endothelial cells(HUVECs).Extract of M.meretrix Linnaeus(AFG-25) was prepared with acetone and ethanol precipitation,and further separated by Sephadex G-25 column.The results show that AFG-25 promoted proliferation,migration,and capillary-like tube formation in HUVECs,and in the presence of eNOS inhibitor NMA,the tube formation induced by AFG-25 is inhibited significantly.Moreover,AFG25 could also promote the activation of endothelial nitric oxide synthase(eNOS) and the resultant elevation of nitric oxide(NO) production.The results suggested that M.meretrix contains active ingredients with angiogentic activity and eNOS/NO signal pathway is in part involved in the proangiogenesis effect induced by AFG-25.展开更多
Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal functio...Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal function is unclear. Therefore, the purpose of our study was to observe the effects of infrasound on gastric motiliW and gastric morphology and to assess the expression of nitric oxide synthase (NOS) in gastric antrum after exposure to infrasound of 8 Hz - 130 dB for 2 hours per day for 14 consecutive days. Gastric motility was assessed by gastric fluid-emptying rate. Gastric morphology was evaluated by HE. The expression of NOS was measured by tissue microarray technology. The results would contribute to understand the role of infrasound in gastroenterology, and help to explain the mechanism of infrasound on gastroenterology.展开更多
To study the effects of Siqi decoction on rats with Myocardial Ischemia, the model of Myocardium Ischemia was made for the Wistar rats cured with posterior pituitary injection through vein in tail. Siqi decoction, Dia...To study the effects of Siqi decoction on rats with Myocardial Ischemia, the model of Myocardium Ischemia was made for the Wistar rats cured with posterior pituitary injection through vein in tail. Siqi decoction, Diaoxinxuekang(DK) and Fufangdanshenpian(FD), the latter two drugs of which were effective TCM drugs of anti-Myocardial Ischemia at present, were administrated to the rats with Myocardium Ischemia for 5 days to compare the effect of anti-Myocardium Ischemia as reference drugs by measuring the changes of NO concentration and activity of NOS in the rat blood serum with Myocardial Ischemia. There was a remarkable increase in the NO concentration and activity of NOS in serum in Siqi decoction groups compared with those in control group(p〈0.05). The results of the prevention group in experiment of Siqi decoction are better than those of the cure group. Siqi decoction was really fit for Myocardium Ischemia via increasing NO concentration by stimulating the activity of NOS in serum. The effect of Siqi decoction against Myocardium Ischemia in preventive group is better than the curative that of Siqi decoction in the curative group.展开更多
A series of Nω-nitro-Nω’-substituted guanidines has been prepared as potential inhibitors of the human Nitric Oxide Synthase (NOS) isoforms. The reported utility of amino-guanidine and nitroarginine in iNOS inhibit...A series of Nω-nitro-Nω’-substituted guanidines has been prepared as potential inhibitors of the human Nitric Oxide Synthase (NOS) isoforms. The reported utility of amino-guanidine and nitroarginine in iNOS inhibition points to a potential similar utility for analogs of nitro-guanidine. The compound library was tested against the three isoforms of Nitric Oxide Synthase (eNOS, iNOS and nNOS). Several candidates showed excellent activity and good selectivity for nNOS. One particular compound even demonstrated good selectivity for iNOS. The potential usefulness of such selective inhibitors is discussed.展开更多
BACKGROUND: Some researches showed that motoneurons in spinal cord anterior horn wound die following brachial plexus injury, but the concrete mechanism of motoneurons death remains unclear. OBJECTIVE: To observe the e...BACKGROUND: Some researches showed that motoneurons in spinal cord anterior horn wound die following brachial plexus injury, but the concrete mechanism of motoneurons death remains unclear. OBJECTIVE: To observe the expression of nitric oxide synthase (NOS) and survival of C7 motoneurons in spinal cord of rats after selective brachial plexus injury. DESIGN: A randomized controlled animal experiment. SETTING:Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University. MATERIALS: Totally 35 adult healthy male Sprague-Dawley rats with the body mass of 200-300 g were provided by Experimental Animal Center, Sun Yet-sen Medical College, Sun Yat-sen University. The rats were divided into control group (n =5) and experimental group(n =30) by random number table method, and the experimental group was divided into three injury subgroups: anterior root avulsion group, dorsal root transection group and spinal cord hemisection group, 10 rats in each group. There were horse anti-neuronal NOS (nNOS) polycolonal antibody (Sigma company) and nicotina mideadeninedinucleotide phosphate (NADPH-d) (Sigma Company). METHODS: The experiment was performed at Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University between September 2004 and April 2005. ①After anesthetizing the rats, the spinous process of second thoracic vertebra as a marker, the vertebra was exposed from C5 to T1 and the lamina of vertebra was unclenched, and spinal dura mater was carved to expose the spinal nerve dorsal roots of C5-T1. The right ventral root of C7 was avulsed, and the residual root was removed in anterior root avulsion group. The right ventral root of C7 was avulsed and the right dorsal roots of brachial plexus (C5-T1) were cut off in dorsal root transection group. In spinal cord hemisection group, the hemisection between the C5 and C6 spinal segment on right side and avulsion of right ventral root of C7 were made. In the control group, the vertebra from C5 to T1 was unclenched and the skin of wound was sutured. ②Three weeks after operation, behavior of rats was observed. The rats were killed after anesthesia. The C7 segment of spinal cord was removed and treated with NADPH-d staining, neutral red counterstaining and NOS immunohistochemistry staining to detect the expression of NOS. MAIN OUTCOME MEASURES: The expression of NOS and survival of C7 motoneurons in spinal cord of rats 3 weeks after operation. RESULTS: Among the 35 included rats, 3 rats died 2 weeks following operation, so totally 32 rats were involved in the result analysis. ①NADPH-d positive neurons of in anterior horn of C7 in the three groups: The NADPH-d positive neurons could be found in anterior horn of C7 in the three groups. The percentage of that in anterior root avulsion group to that of non-injury side of spinal cord was(20.98±2.65)%, (29.43±6.81)% in dorsal root transection group and (31.74±6.80)% in spinal cord hemisection group. There was significant difference among the three injury groups(F =5.135,P =0.016). There was significant difference in anterior root avulsion group with dorsal root transection group and spinal cord hemisection group (t =2.562,3.167,P < 0.05). There was no significant difference between the dorsal root transection group and spinal cord hemisection group (P =0.534). ②survival rate of motoneurons in anterior horn of C7: There were dead motoneurons in the three injury groups, the percentages of surviving motoneurons to that of non-injured side of spinal cord were (69.22±4.04)%,(62.01±3.82)% and (56.74±6.86)%, respectively. There were significant differences among the three groups (F =9.508,P =0.002). The anterior root avulsion group was significantly different from the other two groups(t =2.764,4.587,P < 0.05). There was no significant difference between the dorsal root transection group and spinal cord hemisection group(P =0.073). CONCLUSION: The selective brachial plexus injury can induce the up-regulation of NOS expression in motorneurons of spinal cord anterior horn and block descending pathway of cortex to cause the more significant up-regulation of NOS and low survival rate in motoneurons. It indicates that descending pathway of cortex can inhibit the NOS expression in motorneurons of spinal cord anterior horn, and the high NOS expression might induce the death of motorneurons in spinal cord anterior horn.展开更多
基金Supported by The Mazandaran University of Medical Sciences,No. 88-512
文摘AIM: To investigate the association of the inducible ni- tric oxide synthetase (iNOS) C150T polymorphism with Helicobacter pylori (H. pylor/) infection and gastric can- cer (GC) risk in Iran. METHODS: In order to determine whether there was a correlation between iNOS genotype and GC in Iran, we conducted a case-control study using samples from 329 individuals. For each sample, the C150T ilVOS poly- morphism was genotyped by polymerase chain reaction (PCR) and restriction digestion. Patients were grouped by cancer presence, demographic and behavior charac- teristics, and/-/, pylori infection status. Statistical tests were conducted to determine whether any behavioral factors or a particular iNOS genotype was associated with GC in the study population. RESULTS: In this population, we found that smok- ing, hot beverage consumption, a familial history of GC and H. pylori infection status were significantly associated with GC development (P = 0.015, P 〈 0.001, P = 0.0034, and P 〈 0.015, respectively). The distribution of the C150T ilVOS genotypes among the two study groups was not statistically significant alone, but was impacted by H. pylori infection status. When compared to the non-/-/, pylori infected group, cancer patients who had a heterozygous CT genotype and were also infected with H. pylori were 2.1 times more at risk of developing GC [odds ratio (OR) = 2.1, P = 0.03] while those with a homozygous TT genotype and infected with H. pylori were 5.0 times more at risk of developing GC (OR = 5.0, P = 0.029). In contrast, this association was not seen in patients in the control group.CONCLUSION: ACT or TT polymorphism at position 150 in the iNO$ gene significantly increases the risk of GC and may be a marker for GC susceptibility.
文摘The aim of this study was to determine the immunoreactivity of neuronal and inducible nitric oxide synthetase, argininosuccinate synthetase, argininosuccinate lyase, glutamine synthetase in different regions of brain in rats of kainic acid mediated epilepsy. Male Sprague-Dawley rats were used in this study. The acute group animals were sacrificed after 2 hours and the chronic group animals were sacrificed after 5 days of a single subcutaneous injection of kainic acid (15 mg/kg body weight). The cerebral cortex, cerebellum and brain stem slices were fixed and immunohistostained for the above enzymes. Images were captured and analyzed. In acute group, argininosuccinate synthetase and inducible nitric oxide synthetase were increased in cerebral cortex and cerebellum, neuronal nitric oxide synthetase increased in cerebral cortex and brain stem, and there was no change in argininosuccinate lyase immunoreactivity compared to control group. In chronic group, glutamine synthetase was decreased and all other enzymes immunoreactivity was increased in all the brain regions tested. This study demonstrated the up-regulation of citrul-line-nitric oxide cycle enzymes and may contribute to enhancing recycling of citrulline to arginine to support the increased production of nitric oxide in epilepsy. The decreased glutamine synthetase may increase glutamate in chronic epilepsy and may lead to neurodegeneration.
文摘Objective To observe the expression of nitric oxide syhthetase(NOS) in hippocampus CA1 neurons with hyperglycemia.Method NADPH d histochemical method was used.Rcsults NOS positive neurons expressed in hippocampus CA1 and nomal neurons of 6 weeks old rats with hyperglycemia(DM) and normal rats(NC).There was significant difference in neurons between DM group and control group.Conclusion NOS positive neurons decrease in hippocampus CA1 of rats with hyperglycemia.
文摘NO is now known to be an important messenger molecule in biology.It regulates a variety of functions within cells and tissues including vasodilation, neurotransmission and immunological process. This review will focus on the nitric oxide synthase gene family and recent progress on molecular genetic analysis of NOS1, NOS2 and N0S3 genes.
文摘Stavudine, a potent anti HIV and AIDS related complex, is one of the Nucleoside Analogue Reverse Transcriptase Inhibitors (NARTIs). It is phosphorylated intracellularly and then inhibits the viral reverse transcriptase by acting as a false substrate. Modifications made on the hydrogen labile at the 5' position on the sugar is an interesting template for the elaboration of new potent anti HIV and AIDS drugs. The expected advantages of the modified stavudine prodrugs can be multiple: synergistic drug activities, enhancement of stavudine intracellular uptake, increase of stavudine brain delivery, and bypass of the first stavudine phosphorylation step into the cells. Nitric oxide synthase inhibitors of stavudine and nitric oxide donors of stavudine may hold significant promise for the treatment of HIV and AIDS.
文摘Objective: Functional significance of NO and central inhibitory neurotransmitter γ-aminobutyric(GABA) during seizures were investigated morphorlogically. Methods: A kainate-induced complex partialseizure model was used in our experiment. Twenty SD rats were randomly divided into KA 30, 60, 90, 200min and control groups. The brain sections were stained by NADPh (nicotinamide adenine dinucleotide phosphate ) diaphorase (Nd ) histochemically, and were further stained by GABA immunohistochemically.Results: Histological and immunohistochemical study revealed that in KA groups the number of Nd and GABA-positive double labelled neurons in CA3 region, CA3 region and dentate gyms was significantly reduced,compared with the control group. Conclusion: Nd coexisted with GABA in the brain. Reduction of GABA release led to relief of GABA-ergic inhibition and in the same way, reduction of NO release weakened its negative feedback modulation. Therefore neuronal synchronous paroxysmal discharges increased. GABA and NO,both having antiepileptic action, acted through different ways or different link in the same way. NO may involve in the effect of GABA-ergic neurons and play cooperative antiepileptic action with GABA.
基金Supported by the Innovative Drug Development Projects of China(Nos. 2009ZX09103-661 and 2009ZX09102)the National Natural Science Foundation of China(No.81001396)
文摘Meretrix meretrix Linnaeus has long been used as traditional Chinese medicine in oriental medicine.The angiogentic activity of the extract of M.meretrix was investigated in this study,using human umbilical vein endothelial cells(HUVECs).Extract of M.meretrix Linnaeus(AFG-25) was prepared with acetone and ethanol precipitation,and further separated by Sephadex G-25 column.The results show that AFG-25 promoted proliferation,migration,and capillary-like tube formation in HUVECs,and in the presence of eNOS inhibitor NMA,the tube formation induced by AFG-25 is inhibited significantly.Moreover,AFG25 could also promote the activation of endothelial nitric oxide synthase(eNOS) and the resultant elevation of nitric oxide(NO) production.The results suggested that M.meretrix contains active ingredients with angiogentic activity and eNOS/NO signal pathway is in part involved in the proangiogenesis effect induced by AFG-25.
基金financially supported by the Shaanxi province science and technology project[grant number 2005k12-G1-3]
文摘Infrasound widely condition, productive exists in nature, our living and traffic environment. Gastrointestinal tract is relatively sensitive to infrasound. However, the effect of infrasound on gastrointestinal function is unclear. Therefore, the purpose of our study was to observe the effects of infrasound on gastric motiliW and gastric morphology and to assess the expression of nitric oxide synthase (NOS) in gastric antrum after exposure to infrasound of 8 Hz - 130 dB for 2 hours per day for 14 consecutive days. Gastric motility was assessed by gastric fluid-emptying rate. Gastric morphology was evaluated by HE. The expression of NOS was measured by tissue microarray technology. The results would contribute to understand the role of infrasound in gastroenterology, and help to explain the mechanism of infrasound on gastroenterology.
基金Natural Science Foundation of Jilin Province, China(No.20050561)
文摘To study the effects of Siqi decoction on rats with Myocardial Ischemia, the model of Myocardium Ischemia was made for the Wistar rats cured with posterior pituitary injection through vein in tail. Siqi decoction, Diaoxinxuekang(DK) and Fufangdanshenpian(FD), the latter two drugs of which were effective TCM drugs of anti-Myocardial Ischemia at present, were administrated to the rats with Myocardium Ischemia for 5 days to compare the effect of anti-Myocardium Ischemia as reference drugs by measuring the changes of NO concentration and activity of NOS in the rat blood serum with Myocardial Ischemia. There was a remarkable increase in the NO concentration and activity of NOS in serum in Siqi decoction groups compared with those in control group(p〈0.05). The results of the prevention group in experiment of Siqi decoction are better than those of the cure group. Siqi decoction was really fit for Myocardium Ischemia via increasing NO concentration by stimulating the activity of NOS in serum. The effect of Siqi decoction against Myocardium Ischemia in preventive group is better than the curative that of Siqi decoction in the curative group.
文摘A series of Nω-nitro-Nω’-substituted guanidines has been prepared as potential inhibitors of the human Nitric Oxide Synthase (NOS) isoforms. The reported utility of amino-guanidine and nitroarginine in iNOS inhibition points to a potential similar utility for analogs of nitro-guanidine. The compound library was tested against the three isoforms of Nitric Oxide Synthase (eNOS, iNOS and nNOS). Several candidates showed excellent activity and good selectivity for nNOS. One particular compound even demonstrated good selectivity for iNOS. The potential usefulness of such selective inhibitors is discussed.
文摘BACKGROUND: Some researches showed that motoneurons in spinal cord anterior horn wound die following brachial plexus injury, but the concrete mechanism of motoneurons death remains unclear. OBJECTIVE: To observe the expression of nitric oxide synthase (NOS) and survival of C7 motoneurons in spinal cord of rats after selective brachial plexus injury. DESIGN: A randomized controlled animal experiment. SETTING:Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University. MATERIALS: Totally 35 adult healthy male Sprague-Dawley rats with the body mass of 200-300 g were provided by Experimental Animal Center, Sun Yet-sen Medical College, Sun Yat-sen University. The rats were divided into control group (n =5) and experimental group(n =30) by random number table method, and the experimental group was divided into three injury subgroups: anterior root avulsion group, dorsal root transection group and spinal cord hemisection group, 10 rats in each group. There were horse anti-neuronal NOS (nNOS) polycolonal antibody (Sigma company) and nicotina mideadeninedinucleotide phosphate (NADPH-d) (Sigma Company). METHODS: The experiment was performed at Department of Anatomy, Sun Yet-sen Medical College, Sun Yet-sen University between September 2004 and April 2005. ①After anesthetizing the rats, the spinous process of second thoracic vertebra as a marker, the vertebra was exposed from C5 to T1 and the lamina of vertebra was unclenched, and spinal dura mater was carved to expose the spinal nerve dorsal roots of C5-T1. The right ventral root of C7 was avulsed, and the residual root was removed in anterior root avulsion group. The right ventral root of C7 was avulsed and the right dorsal roots of brachial plexus (C5-T1) were cut off in dorsal root transection group. In spinal cord hemisection group, the hemisection between the C5 and C6 spinal segment on right side and avulsion of right ventral root of C7 were made. In the control group, the vertebra from C5 to T1 was unclenched and the skin of wound was sutured. ②Three weeks after operation, behavior of rats was observed. The rats were killed after anesthesia. The C7 segment of spinal cord was removed and treated with NADPH-d staining, neutral red counterstaining and NOS immunohistochemistry staining to detect the expression of NOS. MAIN OUTCOME MEASURES: The expression of NOS and survival of C7 motoneurons in spinal cord of rats 3 weeks after operation. RESULTS: Among the 35 included rats, 3 rats died 2 weeks following operation, so totally 32 rats were involved in the result analysis. ①NADPH-d positive neurons of in anterior horn of C7 in the three groups: The NADPH-d positive neurons could be found in anterior horn of C7 in the three groups. The percentage of that in anterior root avulsion group to that of non-injury side of spinal cord was(20.98±2.65)%, (29.43±6.81)% in dorsal root transection group and (31.74±6.80)% in spinal cord hemisection group. There was significant difference among the three injury groups(F =5.135,P =0.016). There was significant difference in anterior root avulsion group with dorsal root transection group and spinal cord hemisection group (t =2.562,3.167,P < 0.05). There was no significant difference between the dorsal root transection group and spinal cord hemisection group (P =0.534). ②survival rate of motoneurons in anterior horn of C7: There were dead motoneurons in the three injury groups, the percentages of surviving motoneurons to that of non-injured side of spinal cord were (69.22±4.04)%,(62.01±3.82)% and (56.74±6.86)%, respectively. There were significant differences among the three groups (F =9.508,P =0.002). The anterior root avulsion group was significantly different from the other two groups(t =2.764,4.587,P < 0.05). There was no significant difference between the dorsal root transection group and spinal cord hemisection group(P =0.073). CONCLUSION: The selective brachial plexus injury can induce the up-regulation of NOS expression in motorneurons of spinal cord anterior horn and block descending pathway of cortex to cause the more significant up-regulation of NOS and low survival rate in motoneurons. It indicates that descending pathway of cortex can inhibit the NOS expression in motorneurons of spinal cord anterior horn, and the high NOS expression might induce the death of motorneurons in spinal cord anterior horn.