L-Serine is considered a functional amino acid in the central nervous system, and induces sedation and hypnotic effects in some animal models of acute and chronic stress. Accordingly, while L-serine is a candidate ant...L-Serine is considered a functional amino acid in the central nervous system, and induces sedation and hypnotic effects in some animal models of acute and chronic stress. Accordingly, while L-serine is a candidate anti-stress factor, the central mechanism of L-serine is not clear. The present study clarifies the action of L-serine using acute chick brain slices. We investigated the changes in some extracellular fluid amino acid concentrations in response to L-serine perfusion. Taurine concentration decreased while L-alanine concentration increased following L-serine perfusion. To examine the involvement of the taurine transporter, the effect of L-serine on the taurine concentration in the presence and absence of Na+ was also investigated. Na+ had no effect on taurine concentration induced by L-serine perfusion. These results suggest that L-serine has an ability to promote L-alanine synthesis facilitating the catabolism of taurine. In conclusion, L-serine modifies the metabolism of taurine and L-alanine in the extracellular space in chick brain.展开更多
A novel adsorber,polyvinylidene fluoride matrix immobilized with L-serine ligand (PVDF-Ser),was developed in the present study to evaluate its safety and therapeutic efficacy in septic pigs by extracorporeal hemoperfu...A novel adsorber,polyvinylidene fluoride matrix immobilized with L-serine ligand (PVDF-Ser),was developed in the present study to evaluate its safety and therapeutic efficacy in septic pigs by extracorporeal hemoperfusion.Endotoxin adsorption efficiency (EAE) of the adsorber was firstly measured in vitro.The biocompatibility and hemodynamic changes during extracorporeal circulation were then evaluated.One half of 16 pigs receiving lipopolysaccharide (Escherichia coli O111:B4,5 μg/kg) intravenously in 1 h were consecutively treated by hemoperfusion with the new adsorber for 2 h.The changes of circulating endotoxin and certain cytokines and respiratory function were analyzed.The 72 h-survival rate was assessed eventually.EAE reached 46.3% (100 EU/ml in 80 ml calf serum) after 2 hcirculation.No deleterious effect was observed within the process.The plasma endotoxin,interleukin-6 (IL-6),and tumor necrosis factor-α (TNF-α) levels were decreased during the hemoperfusion.Arterial oxygenation was also improved during and after the process.Furthermore,the survival time was significantly extended (>72 h vs.47.5 h for median survival time).The novel product PVDF-Ser could adsorb endotoxin with high safety and efficacy.Early use of extracorporeal hemoperfusion with the new adsorber could reduce the levels of circulating endotoxin,IL-6,and TNF-α,besides improve respiratory function and consequent 72 h-survival rate of the septic pigs.Endotoxin removal strategy with blood purification using the new adsorber renders a potential promising future in sepsis therapy.展开更多
文摘L-Serine is considered a functional amino acid in the central nervous system, and induces sedation and hypnotic effects in some animal models of acute and chronic stress. Accordingly, while L-serine is a candidate anti-stress factor, the central mechanism of L-serine is not clear. The present study clarifies the action of L-serine using acute chick brain slices. We investigated the changes in some extracellular fluid amino acid concentrations in response to L-serine perfusion. Taurine concentration decreased while L-alanine concentration increased following L-serine perfusion. To examine the involvement of the taurine transporter, the effect of L-serine on the taurine concentration in the presence and absence of Na+ was also investigated. Na+ had no effect on taurine concentration induced by L-serine perfusion. These results suggest that L-serine has an ability to promote L-alanine synthesis facilitating the catabolism of taurine. In conclusion, L-serine modifies the metabolism of taurine and L-alanine in the extracellular space in chick brain.
基金Project (No.2007C33008) supported by the Key Scientific and Technological Project of Science and Technology Department of Zhejiang Province,China
文摘A novel adsorber,polyvinylidene fluoride matrix immobilized with L-serine ligand (PVDF-Ser),was developed in the present study to evaluate its safety and therapeutic efficacy in septic pigs by extracorporeal hemoperfusion.Endotoxin adsorption efficiency (EAE) of the adsorber was firstly measured in vitro.The biocompatibility and hemodynamic changes during extracorporeal circulation were then evaluated.One half of 16 pigs receiving lipopolysaccharide (Escherichia coli O111:B4,5 μg/kg) intravenously in 1 h were consecutively treated by hemoperfusion with the new adsorber for 2 h.The changes of circulating endotoxin and certain cytokines and respiratory function were analyzed.The 72 h-survival rate was assessed eventually.EAE reached 46.3% (100 EU/ml in 80 ml calf serum) after 2 hcirculation.No deleterious effect was observed within the process.The plasma endotoxin,interleukin-6 (IL-6),and tumor necrosis factor-α (TNF-α) levels were decreased during the hemoperfusion.Arterial oxygenation was also improved during and after the process.Furthermore,the survival time was significantly extended (>72 h vs.47.5 h for median survival time).The novel product PVDF-Ser could adsorb endotoxin with high safety and efficacy.Early use of extracorporeal hemoperfusion with the new adsorber could reduce the levels of circulating endotoxin,IL-6,and TNF-α,besides improve respiratory function and consequent 72 h-survival rate of the septic pigs.Endotoxin removal strategy with blood purification using the new adsorber renders a potential promising future in sepsis therapy.
