ObjectiveTo analyze the protective mechanism of spinal cord ischemia-reperfusion injury mediated by N-methyl-D-aspartate (NMDA) receptor.MethodsA total of 42 SD rats were randomly assigned to 4 groups: a non-blocking group (n=6), a saline group (n=12), a NMDA receptor blocker K-1024 (25 mg/kg) group (n=12) and a voltage-gated Ca2+ channel blocker nimodipine (0.5 mg/kg) group (n=12). The medications were injected intraperitoneally 30 min before ischemia. The neural function was evaluated. The neuronal histologic change of spinal cord lumbar region, the release of neurotransmitter amino acids and expression of spinal cord neuronal nitric oxide synthase (nNOS) were compared.ResultsAt 8 h after reperfusion, the behavioral score of the K-1024 group was 2.00±0.00 points, which was statistically different from those of the saline group (5.83±0.41 points) and the nimodipine group (5.00±1.00 points, P<0.05). Compared with the saline group and nimodipine group, K-1024 group had more normal motor neurons (P<0.05). There was no significant difference in glutamic acid concentration in each group at 10 min after ischemia (P=0.731). The nNOS protein expression in the K-1024 group was significantly down-regulated compared with the saline group (P<0.01). After 8 h of reperfusion, the expression of nNOS protein in the K-1024 group was significantly up-regulated compared with the saline group (P<0.05).ConclusionK-1024 plays a protective role in spinal cord ischemia by inhibiting NMDA receptor and down-regulating nNOS protein expression; during the reperfusion, K-1024 has a satisfactory protective effect on spinal cord function, structure and biological activity of nerve cells.
To investigate the function of nitric oxide (NO) and nitric oxide synthetase (NOS) inhibitor, N-nitro-L-arginine methyl ester (L-NAME), the skin avulsion model was made in the lower extremity of pig. The methods of measurement of size of the survived flap, weighing, immunocytochemistry and hybridization in situ were employed, so that the survival surface area of flaps, tissue wet/dry weight ratio, NO content in the serum, gene expression of NO and NOS content in the flap tissue were determined, respectively. The results showed that the early gene expression of NOS was increased as well as the NO content and tissue wet/dry weight ratio (P lt; 0.01). After L-NAME was applied introvenously, the NO content and tissue wet/dry weight ratio were decreased (P lt; 0.01), and the survival surface area of flaps was enlarged (P lt; 0.01). It could be concluded that the NO might play a role in the development of the pathological changes as early congestion, edema and secondary necrosis in the avulsed skin flaps. The early application of L-NAME could do some good to the avulsed skin flap and protect it from further necrosis owing to the presence of NO.
ObjectiveTo understand the effect of nitric oxide (NO) on the formation of hyperdynamic circulatory syndrome (HCS) and the influence of level of NO on HCS. MethodsAfter establishment of stable HCS in partial portal vein ligated rats,the quantity of NO in blood of portal vein and the activity of nitric oxide synthase (NOS) in liver were determined by pre and post injection of inhabitor of NOS (NGmethylLarginine) and hemodynamics was supervised simultaneously.ResultsThe quantity of NO was paralleled with the activity of NOS and was elevated markedly by 24 hours after operation and reached the top by 48 hours after surgery. These sequential changes were coincided with the dilation of general vascularture. There was a close relation between this changes and the formation of HCS.The quantity of NO and the activity of NOS were decreased significantly to the level of the control group after injection of NGmethylLarginine (LNMMA). LNMMA inhabited the activity of NOS and blocked the production of NO. HCS ameliorated obviously. ConclusionNO plays an important role in initiating the dilation of general vascularture and plays a critical role in the formation of HCS. HCS will be ameliorated obviously or be blocked completely by eliminating the effect of NO and the portal pressure will decreased significantly or recover to normal range.
【Abstract】ObjectiveTo explore the changes of colon motility of the rats in multiple organ dysfunction syndrome （MODS） induced bacterial peritonitis and the effects of IL6, TNFα and induce nitricoxide synthase (iNOS) on colon motility. MethodsWistar rats were divided into two groups, which were the control group and the MODS group. The number of stool, the amplitude changes of circular smooth muscle strip, the length of smooth muscle cell, and the changes of serum NO in two groups were observed. The expressions of IL6, TNFα and iNOS protein and IL6 mRNA, TNFα mRNA and iNOS mRNA in distal colon were investigated by using immunohistochemical methods and RTPCR. ResultsThe numbers of stool and the amplitude in the MODS group were lower than those of the control group （P＜0.05）. The expressions of IL6, TNFα and iNOS were negative in the control group, while they were positive in the MODS group. IL6 mRNA,TNFα mRNA and iNOS mRNA were negative expression in the control group, but they were positive expression in the MODS group. The concentration of serum NO and the length of smooth muscle cells in the MODS group were higher than those of the control group (P＜0.01). ConclusionColon motor dysfunction of the rats is related to the iNOS, IL6 and TNFα.
ObjectiveTo investigate the relationship between the changes of nerve cells in sphincter of Oddi and acute pancreatitis.
MethodsThe rabbit models of acute pancreatitis were prepared by using sodium taurocholate perfusion. Immunohistochemical method was used to detect the expressions of nitric oxide synthase (NOS) and vasoactive intestinal peptide (VIP) in neurons of the sphincter of Oddi.
ResultsIn the control group, (45.83±2.17)% of myenteric neurons were NOS-positive, (52.46±2.47)% of myenteric neurons were VIP positive, and (22.73±1.95)% of myenteric neurons were NOS and VIP double positive. In contrast, (11.26±0.93)% of myenteric neurons were NOS-positive and (28.62±2.83)% of myenteric neurons were VIP positive in SAP group, which were significantly less than those of control group (P < 0.01).
ConclusionsThe sphincter of Oddi of normal rabbits is rich in VIP and NOS positive neurons. The significant reduction of NOS-positive and VIP-positive neurons when SAP, which may be the reason of decreased the activities of the sphincter of Oddi.
ObjectiveTo compare the biological features of early and late endothelial progenitor cells (EPCs) by isolating and culturing early and late EPCs from the human peripheral blood so as to find some unique properties of EPCs and to propose a suitable strategy for EPCs identification.
MethodsMononuclear cells were isolated from the human peripheral blood using density gradient centrifugation. Then, the cells were inoculated in human fibronectin-coated culture flasks and cultured in endothelial cell basal medium 2. After 4-7 days and 2-3 weeks culture, early and late EPCs were obtained respectively. The morphology, proliferation potential, surface markers, cytokine secretion, angiogenic ability, and nitric oxide (NO) release were compared between 2 types of EPCs. Meanwhile, the human aortic endothelial cells (HAECs) were used as positive control.
ResultsThe morphology of early and late EPCs was different:early EPCs formed a cell cluster with a spindle shape after 4-7 days of culture, and late EPCs showed a cobblestone appearance. Late EPCs were characterized by high proliferation potential and were able to form capillary tubes on Matrigel, but early EPCs did not have this feature. Both types EPCs could ingest acetylated low density lipoprotein and combine with ulex europaeus Ⅰ. Flow cytometry analysis showed that early EPCs did not express CD34 and CD133, but expressed the CD14 and CD45 of the hematopoietic stem cell markers;however, late EPCs expressed CD31 and CD34 of the endothelial cell markers, but did not express CD14, CD45, and CD133. By RT-PCR analysis, the expressions of vascular endothelial growth receptor 2 and vascular endothelial cadherin in early EPCs were significantly lower than those in the late EPCs and HAECs (P<0.05), but no significant difference was found in the expression of von Willebrand factor and endothelial nitric oxide synthase (eNOS) between 2 type EPCs (P>0.05). The concentrations of vascular endothelial growth factor, granulocyte colony-stimulating factor, and interleukin 8 were significantly higher in the supernatant of early EPCs than late EPCs (P<0.05). Western blot assay indicated eNOS expressed in both types EPCs, while the expression of eNOS in late EPCs was significantly higher than early EPCs at 5 weeks (P<0.05). Both cell types could produce similar amount of NO (P>0.05).
ConclusionThe expression of eNOS and the production of NO could be used as common biological features to identify EPCs, and the strategy of a combination of multiple methods for EPCs identification is more feasible.
