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.
Objective To observe the effects of nitric oxide ( NO) inhalation on lung inflammation of acute lung injury ( ALI) in rats. Methods Twenty-four SD rats were randomly divided into four groups, ie. a normal control group, an ALI group, a 20 ppm NO inhalation group, and a 100 ppm NO inhalation group. ALI model was established by LPS instillation intratracheally and the control group was instilled with normal saline. Then they were ventilated with normal air or NO at different levels, and sacrificed 6 hours later. Pathological changes were evaluated by HE staining. The expression of TLR4 in lung tissues was detected by immunohistochemistry. IL-6 level in lung homogenate was measured by ELISA. Results In the ALI group, the inflammation in bronchus and bronchioles was more apparently, and the expressions of TLR4and IL-6 were elevated significantly compared with the control group. 20 ppm NO inhalation significantly decreased the expression of TLR4 and IL-6, and alleviated the inflammation of ALI. However, 100 ppm NO inhalation did not change TLR4 expression and lung inflammation significantly, and increased IL-6 level.Conclusions Inhalation low level of NO( 20 ppm) can alleviate lung inflammation possibly by reducing theexpression of TLR4 and IL-6.
ObjectiveTo detect the induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in immunostimulated retinal pigment epithelial (RPE) cells to seek for the supplying of the arginine, a substrate for NOS; as well as the effects of produced NO on the tight junction of RPE-J cells.
MethodsRat′s RPE-J cells were treated with interferon-γ(INF-γ), tumor necrosis factor-α(TNF-α) and lipopolysaccharide (LPS), and Northern and Western blotting were applied to analyze the expression of the citrulline-NO cycle enzymes and related enzymes and the effect of dexamethasone and cyclic adenosine monophosphate (camp) on the expression of iNOS. Immunocytochemistry reaction and Western blotting were used to evaluate the effect of produced NO on the tight junctions of RPE-J cells.ResultsiNOS and argininosuccinate synthetase (AS) were highly induced at both mRNA and protection levels in immunostimulated RPE cells while arginiosuccinate lyase (AL) was not induced. NO was produced by cells after stimulation with TNFα, IFNγ and LPS. The induction of iNOS mRNA and the production of NO by these immunostimulated cells was further enhanced by cAMP. NO was produced from citrulline as well as from arginine. And the produced NO impaired the tight junction of RPE-J cells, decreased the production of tight junction related protein ZO-1.ConclusionIn activated RPE-J cells, citrullinearginine recycling is important for NO production, and the produced NO weakened the function of tight junction of RPE-J cells.(Chin J Ocul Fundus Dis, 2005,21:32-36)
【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 study the effect of Schwann cells (SCs) promoting the function of nitric oxide (NO) secretion of bone marrow mesenchymal stem cells (BMSCs) derived endothelial cells so as to lay the experimental foundation for research of the effect of nerves on vessels during the process of tissue engineering bone formation.
MethodsSCs were collected from 1-day-old Sprague Dawley (SD) rats,and identified through S100 immunohistochemistry (IHC).BMSCs were collected from 2-week-old SD rats and induced into endothelial cells (IECs),which were identified through von Willebrand factor (vWF) and CD31 immunofluorescence (IF).Transwell system was used for co-culture of SCs and IECs without contact as the experimental group,and simple culture of IECs served as the control group.The NO concentration in the medium was measured at 1,3,5,and 7 days after culture; the mRNA expressions of nitric oxide synthetase 2 (NOS2) and NOS3 were detected by real-time fluorescence quantitative PCR (RT-qPCR) at 1,3,7,and 10 days.
ResultsSCs and IECs were identified through morphology and immunology indexes of S100 IHC,vWF and CD31 IF.Significant differences were found in the NO concentration among different time points in 2 groups (P<0.05); the NO concentration of the experimental group was significantly higher than that of the control group at the other time points (P<0.05) except at 3 days.NOS2 mRNA expression of the experimental group was significantly higher than that of the control group (P<0.05); difference was significant in the NOS2 mRNA expression among different time points in 2 groups (P<0.05).NOS3 mRNA expression of the experimental group was significantly higher than that of the control group at the other time points (P<0.05) except at 10 days.No significant difference was found in NOS3 mRNA expression among different time points in the experimental group (F=6.673,P=0.062),but it showed significant differences in the control group (F=36.581,P=0.000).
ConclusionSCs can promote NO secretion of BMSCs derived endothelial cells,which is due to promoting the activity of NOS.
