The increasing importance of endothelium-derived relaxing factor(EDRF),which has now been identified as nitric oxide (NO),has been underscored by the eltlcidation of its role'in a growing number of normal and path...The increasing importance of endothelium-derived relaxing factor(EDRF),which has now been identified as nitric oxide (NO),has been underscored by the eltlcidation of its role'in a growing number of normal and pathophysiological processes. Therefore techniques for detection of nitric oxide should serve as useful tools in defining the role of nitric oxide to these processes.We have improved a simple, sensitive assay methods for determination of nitric oxide in blood, tissue, and other body fluids both by fluorometric and by ultraviolet-visible spectrophotometric measurements. Data obtained by floores cence and by UV-visible assay were correlated well (r=0. 9938, P<0. 0001 ).Linearity:0.1￣ 100μmol/L,r =0.9996,P<0.0001. The minimum detection limit were < 10pmol/L. Within-and between-run CVs were 2. 48%and 4. 62% (n = 10),respectively.Reference values for healthy adults(n=40) were(9.82 ± 1. 57) pmol/L. In conclusion:the methods is sensitive, specific,and precise. It is fairly rapid and simple to perform andrequires no pretreatment of sample, i. e., plasma and urine.The value can be obtained by fluorimeter and/or UV-visible spectrophotometer.The present method is sufficiently rapid and simple to make this a practical choice for many laboratories.展开更多
Based on the EDRF(endothelium derived relaxing factor)-like effects for polyarginine Arg-Arg-oH was selected as the lead compound and its derivatives Arg-Arg- OCH_3.Arg Arg-Arg-OH,HO-ArgCOCH_2CH_2COArg-OH,HO-ArgCOCH_2...Based on the EDRF(endothelium derived relaxing factor)-like effects for polyarginine Arg-Arg-oH was selected as the lead compound and its derivatives Arg-Arg- OCH_3.Arg Arg-Arg-OH,HO-ArgCOCH_2CH_2COArg-OH,HO-ArgCOCH_2COArg-OH,were synthesized.These substances showed on bioassay various degrees of vasorelaxant activities. With protection for the C-terminal of Arg-Arg-OH with a methyl ester.the vasorelaxing ac- tivitv was decreased.In contrast.when the N-terminal of Arg-OH was protected with mal- onic acid or butane diacid.the biological activites were lower than those of Arg-Arg-OH due to the lowered metabolic rate.With protection of N-terminal of Arg-Arg-OH with L-Arg residue.Arg-Arg-Arg-OH was obtained,which showed a vasorelaxing activity better than that of Arg-Arg-OH.The bioactivities observed on the Wister's rats for the former com- pound become the experimental basis for prodrug design of EDRF.展开更多
Direct observation was made by using the patch-clamp technique with a specially designed microperfusion system to investigate the effect of acetylcholine (Ach 10^(-6) mol/L) elicited endothelium-derived relaxing facto...Direct observation was made by using the patch-clamp technique with a specially designed microperfusion system to investigate the effect of acetylcholine (Ach 10^(-6) mol/L) elicited endothelium-derived relaxing factor (EDRF) on the calcium-activated potassium channel (IK(Ca))in the smooth muscle cells of mesenteric resistance vessels in Wistar rats. Activation of IK(Ca) was firstly observed by inducing the elicited EDRF or sodium nitroprusside (SNP 10^(-8) mol/L) under various clamping voltages in cell-attached configuration. While the pipette solution contained KCl 126 mmol/L and the bath solution contained KCl 5.9 mmol/L, two types of conductances of calcium-activated potassium current being 76.4±2.3 pS(mean±S.E. n = 7) and 160.3±7.5 pS (mean±S.E. n= 7) were recorded during the EDRF activation, one type of conductance being 100.5±2.8 pS (mean±S.E. n = 6) was activated by nitric oxide (NO) which is an effective component from SNP. Differences in kinetic characteristics of these channels between EDRF and NO activation were found, particularly the probability of the channel being open in EDRF activation was obviously greater than that in NO stimulation. It has been shown that the potassium channel mechanisms involved in the EDRF and NO actions might be different.展开更多
To determine whether the therapeutic effectiveness of testosterone in male elderly coronary heart disease patients is related to the production of nitric oxide (NO), which accounts for the biological activity of endot...To determine whether the therapeutic effectiveness of testosterone in male elderly coronary heart disease patients is related to the production of nitric oxide (NO), which accounts for the biological activity of endothelium derived relaxing factor (EDRF), we studied the regulatory effect of testosterone on production of NO/EDRF in the aorta and cultured vascular endothelial cells. The production of NO/EDRF was detected by the stimulation of cGMP formation in rabbit fetal lung-6 cells. The results showed that testosterone stimulated the production of NO/EDRF in both the aorta and cultured vascular endothelial cells, suggesting that NO/EDRF-dependent vasodilation is one of the mechanism by which testosterone alleviates angina pectoris and improves myocardial ischemia in elderly male coronary heart disease patients.展开更多
Endothelium can release many factorsto affect vascular reaction, vascular structural reconstruction and coagulation. Itplays a central role to regulate and controlthe circulation of human body. ln 198O,Furchgott found...Endothelium can release many factorsto affect vascular reaction, vascular structural reconstruction and coagulation. Itplays a central role to regulate and controlthe circulation of human body. ln 198O,Furchgott found hemangioendothelium canproduce and release a kind of vasoactivesubstance-endothelium derived relaxingfactor (EDRF). In 1988, Moncada proved EDRF was nitrous oxide. Recent studies pointout that under hypoxic condition, dysfunction of pulmonary vascular endothelium occured, endogenous Nltrous ox1de synthesisand release decreased.These may strengthen the pulmonaryvesoconstrictive reaction and vascular structural reconstruction, then cause the formation of pulmonary hypertension.展开更多
文摘The increasing importance of endothelium-derived relaxing factor(EDRF),which has now been identified as nitric oxide (NO),has been underscored by the eltlcidation of its role'in a growing number of normal and pathophysiological processes. Therefore techniques for detection of nitric oxide should serve as useful tools in defining the role of nitric oxide to these processes.We have improved a simple, sensitive assay methods for determination of nitric oxide in blood, tissue, and other body fluids both by fluorometric and by ultraviolet-visible spectrophotometric measurements. Data obtained by floores cence and by UV-visible assay were correlated well (r=0. 9938, P<0. 0001 ).Linearity:0.1￣ 100μmol/L,r =0.9996,P<0.0001. The minimum detection limit were < 10pmol/L. Within-and between-run CVs were 2. 48%and 4. 62% (n = 10),respectively.Reference values for healthy adults(n=40) were(9.82 ± 1. 57) pmol/L. In conclusion:the methods is sensitive, specific,and precise. It is fairly rapid and simple to perform andrequires no pretreatment of sample, i. e., plasma and urine.The value can be obtained by fluorimeter and/or UV-visible spectrophotometer.The present method is sufficiently rapid and simple to make this a practical choice for many laboratories.
基金This project was supported by the National Natural Science Foundation of China
文摘Based on the EDRF(endothelium derived relaxing factor)-like effects for polyarginine Arg-Arg-oH was selected as the lead compound and its derivatives Arg-Arg- OCH_3.Arg Arg-Arg-OH,HO-ArgCOCH_2CH_2COArg-OH,HO-ArgCOCH_2COArg-OH,were synthesized.These substances showed on bioassay various degrees of vasorelaxant activities. With protection for the C-terminal of Arg-Arg-OH with a methyl ester.the vasorelaxing ac- tivitv was decreased.In contrast.when the N-terminal of Arg-OH was protected with mal- onic acid or butane diacid.the biological activites were lower than those of Arg-Arg-OH due to the lowered metabolic rate.With protection of N-terminal of Arg-Arg-OH with L-Arg residue.Arg-Arg-Arg-OH was obtained,which showed a vasorelaxing activity better than that of Arg-Arg-OH.The bioactivities observed on the Wister's rats for the former com- pound become the experimental basis for prodrug design of EDRF.
基金Project supported by the National Natural Science Foundation of China.
文摘Direct observation was made by using the patch-clamp technique with a specially designed microperfusion system to investigate the effect of acetylcholine (Ach 10^(-6) mol/L) elicited endothelium-derived relaxing factor (EDRF) on the calcium-activated potassium channel (IK(Ca))in the smooth muscle cells of mesenteric resistance vessels in Wistar rats. Activation of IK(Ca) was firstly observed by inducing the elicited EDRF or sodium nitroprusside (SNP 10^(-8) mol/L) under various clamping voltages in cell-attached configuration. While the pipette solution contained KCl 126 mmol/L and the bath solution contained KCl 5.9 mmol/L, two types of conductances of calcium-activated potassium current being 76.4±2.3 pS(mean±S.E. n = 7) and 160.3±7.5 pS (mean±S.E. n= 7) were recorded during the EDRF activation, one type of conductance being 100.5±2.8 pS (mean±S.E. n = 6) was activated by nitric oxide (NO) which is an effective component from SNP. Differences in kinetic characteristics of these channels between EDRF and NO activation were found, particularly the probability of the channel being open in EDRF activation was obviously greater than that in NO stimulation. It has been shown that the potassium channel mechanisms involved in the EDRF and NO actions might be different.
文摘To determine whether the therapeutic effectiveness of testosterone in male elderly coronary heart disease patients is related to the production of nitric oxide (NO), which accounts for the biological activity of endothelium derived relaxing factor (EDRF), we studied the regulatory effect of testosterone on production of NO/EDRF in the aorta and cultured vascular endothelial cells. The production of NO/EDRF was detected by the stimulation of cGMP formation in rabbit fetal lung-6 cells. The results showed that testosterone stimulated the production of NO/EDRF in both the aorta and cultured vascular endothelial cells, suggesting that NO/EDRF-dependent vasodilation is one of the mechanism by which testosterone alleviates angina pectoris and improves myocardial ischemia in elderly male coronary heart disease patients.
文摘Endothelium can release many factorsto affect vascular reaction, vascular structural reconstruction and coagulation. Itplays a central role to regulate and controlthe circulation of human body. ln 198O,Furchgott found hemangioendothelium canproduce and release a kind of vasoactivesubstance-endothelium derived relaxingfactor (EDRF). In 1988, Moncada proved EDRF was nitrous oxide. Recent studies pointout that under hypoxic condition, dysfunction of pulmonary vascular endothelium occured, endogenous Nltrous ox1de synthesisand release decreased.These may strengthen the pulmonaryvesoconstrictive reaction and vascular structural reconstruction, then cause the formation of pulmonary hypertension.
