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.
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.
In order to study effect of endothelin (ET-1) on hepatic blood flow in rats and effect of nitric oxide (NO) and prostacyclin (PGI2) on ET-1 biological function, 20 rats were randomized into control, ET-1, ET-1 plus nitric-Larginine, ET-1 plus prostacyclin and indomethen groups. The result showed that ET-1 decreased hepatic blood flow and lasted for longer time. NO and PGI2 may antagonize the biological action of ET-1 during endotoxemia. Therefore, the endothelium-derived vascular factors may regulate hepatic blood flow.
ObjectiveTo study the change and significance of the serum nitric oxide (NO) level in patient with obstructive jaundice complicated with renal dysfunction. MethodsThe level of NO, BUN, Cr in serum and the activity of NOS in 25 patients with obstructive jaundice and renal dysfunction and 26 healthy adults was studied.ResultsThe patients’ serum NO level and the activity of NOS were significantly lower than those in the control group(P＜0.01)，whereas the serum BUN and Cr levels were significantly higher than those in control group(P＜0.01). The linear correlation analysis showed that the serum NO had a negative correlation between serum BUN and Cr level (P＜0.01). ConclusionThe patients with obstructive jaundice and renal dysfunction may lead to the decrease of serum NO level. NO may have some protective effects to the renal function during obstructive jaundice.
Objective To investigate the effects of nitric oxide precursor L-arginine on traumatic pulmonary contusion. Methods Sixty Sprague-Dawley rats were randomly divided into three groups, ie. a normal group, a model group, and a L-arginine group. The model of traumatic pulmonary contusion was established with self-made chest-impacter. Then the rats in the L-arginine group was injected intravenously with L-arginine in a dose of 250 mg/kg. All rats were sacrificed at 24 hours after these models established.Levels of TNF-α and nitric oxide ( NO2 - /NO3- ) in serum were measured by ELISA and diazo-reaction method. Lung wet/dry weight ratio, NF-κB, endothelin-1, apoptotic cell, and ICAM-1 ( intercellular adhesion molecule-1) mRNA expressions in the lung tissue were measured. Results Compared with the model group,TNF-αand lung wet/dry weight ratio decreased significantly in the L-arginine group( P lt; 0. 05) . After the L-arginine treatment, the concentration of nitric oxide, apoptotic index were significantly higher than the model group ( P lt; 0. 05) . The expressions of NF-κB, endothelin-1, and ICAM-1 mRNA in the L-arginine group were lower than those in the model group ( P lt;0. 05) . Conclusion L-arginine treatment can downregulate the expressions of NF-κB, ET-1, ICAM-1 mRNA and apoptosis obviously, and ameliorate the microcirculation of rats lung with traumatic pulmonary contusion.
Objective To study the effect of the competitive inhibitor of nitric oxide synthase NG-nitro-L-arginine methyl ester (LNAME) on thedenervated muscle atrophy. Methods A model of the denervated gastrocnemius atthe right lower limb was established in 36 SD adult rats. The rats were randomly divided into two groups: the L-NAMEgroup (Group A) and the control group(Group B). L-NAME 10 mg/ kg daily was injected into the denervated gastrocnemius inGroup A, and normal saline was injected into the denervated gastrocnemius in Group B. At 2, 4 and 8 weeks after operation, the rate of the muscle wet weight preservation, the cross section area of the myocyte, the protein amount, and the percentage of the apoptotic muscle cells were measured respectively and the ultramicrostructure of the myocyte was observed. Results At 2 and 4 weeks after operation, the rate of the muscle wet weight preservation, the cross section area of themyocyte, and the protein amount were significantly greater in Group A than in Group B; however, the percentage of the apoptotic muscle cells was significantly smaller in Group A than in Group B. The observation of the ultramicrostructure of themyocyte showed that an injection of L-NAME could protect the ultramicrostructure of themyocyte. At 8 weeks after operation, there was no significant difference between the two groups in the abovementioned parameters. Conclusion The nitric oxide synthase inhibition can delay the denervated muscle atrophy.
