IM To observe the kinetics of D()lactate alteration in both portal and systemic circulations, and its relationship with intestinal injury in rats subjected to acute intestinal ischemiareperfusion.METHODS Anesthetize...IM To observe the kinetics of D()lactate alteration in both portal and systemic circulations, and its relationship with intestinal injury in rats subjected to acute intestinal ischemiareperfusion.METHODS Anesthetized rats underwent 75min superior mesenteric artery occlusion followed by 6hour reperfusion. Plasma D()lactate levels were measured by an enzymatic spectrophotometric assay.RESULTS Intestinal ischemia for 75 min resulted in a significant elevation of D()lactate levels in portal vein as compared with the baseline values (P<005). Plasma D()lactate levels had a tendency to further increase after reperfusion up to 6 hours. Similar alterations in D()lactate were also found in systemic circulation, there were no significant differences between the portal and systemic circulations at any time point. Moreover, the macropathological evaluation scores were significantly correlated to the portal D()lactate levels in animals at various time points (r=0415, P<001). In addition,there was a remarkable rise of endotoxin concentration within the portal vein at the end of 75min ischemia (P<005), reaching a peak at 2 hours postreperfusion.CONCLUSION Acute intestinal ischemia is associated with failure of mucosal barrier resulting in increased plasma D()lactate levels in both portal and systemic blood. The subsequent reperfusion might further increase D()lactate levels, which are correlated to the macropathological alterations. Plasma D()lactate may be a useful marker of intestinal injury following both ischemia and reperfusion insults.展开更多
BACKGROUND: Plasma D(-)-lactate and diamine oxidase (DAO) can reflect patients' intestinal mucosal condition. We evaluated the changes of plasma D (-)-lactate, DAO and endotoxin activities and their significance i...BACKGROUND: Plasma D(-)-lactate and diamine oxidase (DAO) can reflect patients' intestinal mucosal condition. We evaluated the changes of plasma D (-)-lactate, DAO and endotoxin activities and their significance in patients with liver cirrhosis. METHODS: Fifty liver cirrhosis patients were enrolled into experimental group and 30 healthy people into control group. The plasma levels of D(-)-lactate, DAO and endo- toxin were detected spectrophotographically. RESULTS: The level of D(-)-lactate was significantly high- er in the experimental group than that in the control group (P<0.01). Significant differences of D (-)-lactate levels were observed in Child-Pugh subgroups of the experimen- tal group (P <0. 01). The level of DAO was significantly higher in the experimental group than that in the control group (P <0.01), but the level of DAO in Child-Pugh sub- group C was significantly lower than that in Child-Pugh subgroup B (P<0.01). The level of endotoxin was signifi- cantly increased in the experimental group except Child Pugh subgroup A (P<0.01). The plasma levels of D(-) lactate, DAO and endotoxin were positively correlated with each other (P<0.01). CONCLUSIONS: The data suggest that both plasma D(-) lactate and DAO activity are sensitive markers for early diagnosis of gut failure and endotoxemia in patients with liver cirrhosis. The impairment of intestinal barrier func- tion may be one of the critical reasons for deterioration of liver cirrhosis.展开更多
AIM To explore the kinetic changes in plasma D(-)- lactate and lipopolyssccharide(LPS)levels,and investigate whether D(-)-lactate could be used as a marker of intestinal injury in rats following gut ischemia/ reperfus...AIM To explore the kinetic changes in plasma D(-)- lactate and lipopolyssccharide(LPS)levels,and investigate whether D(-)-lactate could be used as a marker of intestinal injury in rats following gut ischemia/ reperfusion,burn,and acute necrotizing pancreatitis (ANP). METHODS Three models were developed in rats:① gut ischemia/ reperfusion obtained by one hour of superior mesenteric artery occlusion followed by reperfusion;② severe burn injury created by 30% of total body surface area(TBSA)full-thickness scald burn;and ③ ANP induced by continuous inverse infusion of sodium taurocholate and trypsin into main pancreatic duct. Plasma levels of D(-)-lactate in systemic circulation and LPS in portal circulation were measured by enzymatic- spectrophotometric method and limulus amebocyte lysate (LAL)test kit,respectively.Tissue samples of intestine were taken for histological analysis. RESULTS One hour gut ischemia followed by reperfusion injuries resulted in a significant elevation in plasma D(-)- lactate and LPS levels,and there was a significant correlation between the plasma D(-)-lactate and LPS(r =0.719,P<0.05).The plasma concentrations of D(-)- lactate and LPS increased significantly at 6h postburn, and there was also a remarkable correlation between them (r = 0.877,P < 0.01).D(-)-lactate and LPS levels elevated significantly at 2h after ANP,with a similar significant correlation between the two levels(r = 0.798, P < 0.01 ).The desquamation of intestine villi and infiltration of inflammatory cells in the lamina propria were observed in all groups. CONCLUSION The changes of plasma D(-)-lactate levels in systemic blood paralleled with LPS levels in the portal vein blood.The measurement of plasma D(-)-lactate level may be a useful marker to assess the intestinal injury and to monitor an increase of intestinal permeability and endotoxemia following severe injuries in early stage.展开更多
D-Lactate-utilizing bacteria play important roles in maintaining the balance of gut lactate; however, studies on gut D-lactate-uti-lizing bacteria have been limited. This study aimed to isolate and identify D-lactate-...D-Lactate-utilizing bacteria play important roles in maintaining the balance of gut lactate; however, studies on gut D-lactate-uti-lizing bacteria have been limited. This study aimed to isolate and identify D-lactate-utilizing bacteria from pig gut using the Hungate rol-tube method, and to investigate their metabolic characteristicsin vitro. Six different anaerobes were isolated from pig feces, which were identiifed as related toBacteroides fragilis, Bacteroides acidifaciens,Veilonela denticariosi, Veilonela caviae,Bacteroides uniformis, andMegasphaera elsdenibased on the 16S rRNA gene sequences. Al strains had a signiifcant ability to utilize D-lactate, which was concluded afterin vitro fermentation with 25 mmol L–1 D-lactate as the primary carbon source. Of al 6 strains,M. elsdeniJ6 showed the highest efifciency of D-lactate utilization and produced a higher ratio of butyrate in total short chain fatty acids （SCFAs）. Thus, thein vitro fermentation characteristics of this strain in D-, L-, and DL-lactate mixtures （D-lactate：L-lactate=1：1 or 1：2） were further studied. The results showed that M. elsdeni J6 preferred utilizing D-lactate, and produced more SCFA when using D-lactate as the primary carbon source. The ifndings suggest that the administration of D-lactate-utilizing bacteria such asM. elsdeni J6 may have a potential advantage in the aleviation of D-lactic acidosis in the animal gut.展开更多
Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whe...Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whether pretreatment with monoclonal antibody against TNF-α (TNF-α MoAb) would affect the release of D(-)-lactate after local gut ischemia followed by reperfusion. Methods Anesthetized Sprague-Dawley rats underwent superior mesenteric artery occlusion for 75 min followed by reperfusion for 6 hr. The rats were treated intravenously with either TNF-α MoAb (20 mg/kg) or albumin (20 mg/kg) 30 min prior to the onset of ischemia. Plasma D(-)-lactate levels were measured in both the portal and systemic blood by an enzymatic spectrophotometric assay. Intestinal TNF-αmRNA expression as well as protein levels were also measured at various intervals. In addition, a postmortem examination was performed together with a macropathological evaluation based on a four-grade scoring system.Results Intestinal ischemia resulted in a significant elevation in D(-)-lactate levels in the portal vein blood in both the control and treatment groups ( P ＜0.05). However, animals pretreated with TNF-α MoAb at 6 hr after reperfusion showed significant attenuation of an increase in both portal and systemic D(-)-lactate levels when compared with those only receiving albumin (P ＜ 0.05). In the control animals, a remarkable rise in intestinal TNF-α level was measured at 0.5 hr after clamp release ( P ＜ 0.01); however, prophylactic treatment with TNF-α MoAb completely annulled the increase of local TNF-α levels seen in the control animals. Similarly, after anti-TNF-α MoAb administration, intestinal TNF-α mRNA expression was markedly inhibited, which showed significant differences when compared with the control group at 0.5 hr, 2 hr and 6 hr after the release of occlusion ( P ＜ 0.05-0.01 ). In addition, the pathological examination showed marked intestinal lesions that formed during ischemia, which were much worse upon reperfusion,particularly at the 6 hr time point. These acute injuries were obviously attenuated in animals receiving TNF-α MoAb.Conclusions It appeared that acute intestinal ischemia was associated with failure of the mucosal barrier, resulting in increased plasma D(-)-lactate levels in both portal and systemic blood. These results suggest that TNF-α appears to be involved in the development of local damage associated with intestinal ischemic injury. Moreover, prophylactic treatment with TNF-α MoAb exerts preventive effects on ischemia/ reperfusion-induced circulating D (-)-lactate elevation and gut injury. ( J Geriatr Cardiol 2004;1(2):119-124. )展开更多
文摘IM To observe the kinetics of D()lactate alteration in both portal and systemic circulations, and its relationship with intestinal injury in rats subjected to acute intestinal ischemiareperfusion.METHODS Anesthetized rats underwent 75min superior mesenteric artery occlusion followed by 6hour reperfusion. Plasma D()lactate levels were measured by an enzymatic spectrophotometric assay.RESULTS Intestinal ischemia for 75 min resulted in a significant elevation of D()lactate levels in portal vein as compared with the baseline values (P<005). Plasma D()lactate levels had a tendency to further increase after reperfusion up to 6 hours. Similar alterations in D()lactate were also found in systemic circulation, there were no significant differences between the portal and systemic circulations at any time point. Moreover, the macropathological evaluation scores were significantly correlated to the portal D()lactate levels in animals at various time points (r=0415, P<001). In addition,there was a remarkable rise of endotoxin concentration within the portal vein at the end of 75min ischemia (P<005), reaching a peak at 2 hours postreperfusion.CONCLUSION Acute intestinal ischemia is associated with failure of mucosal barrier resulting in increased plasma D()lactate levels in both portal and systemic blood. The subsequent reperfusion might further increase D()lactate levels, which are correlated to the macropathological alterations. Plasma D()lactate may be a useful marker of intestinal injury following both ischemia and reperfusion insults.
文摘BACKGROUND: Plasma D(-)-lactate and diamine oxidase (DAO) can reflect patients' intestinal mucosal condition. We evaluated the changes of plasma D (-)-lactate, DAO and endotoxin activities and their significance in patients with liver cirrhosis. METHODS: Fifty liver cirrhosis patients were enrolled into experimental group and 30 healthy people into control group. The plasma levels of D(-)-lactate, DAO and endo- toxin were detected spectrophotographically. RESULTS: The level of D(-)-lactate was significantly high- er in the experimental group than that in the control group (P<0.01). Significant differences of D (-)-lactate levels were observed in Child-Pugh subgroups of the experimen- tal group (P <0. 01). The level of DAO was significantly higher in the experimental group than that in the control group (P <0.01), but the level of DAO in Child-Pugh sub- group C was significantly lower than that in Child-Pugh subgroup B (P<0.01). The level of endotoxin was signifi- cantly increased in the experimental group except Child Pugh subgroup A (P<0.01). The plasma levels of D(-) lactate, DAO and endotoxin were positively correlated with each other (P<0.01). CONCLUSIONS: The data suggest that both plasma D(-) lactate and DAO activity are sensitive markers for early diagnosis of gut failure and endotoxemia in patients with liver cirrhosis. The impairment of intestinal barrier func- tion may be one of the critical reasons for deterioration of liver cirrhosis.
基金the Fund for National Outstanding Young Researchers of China
文摘AIM To explore the kinetic changes in plasma D(-)- lactate and lipopolyssccharide(LPS)levels,and investigate whether D(-)-lactate could be used as a marker of intestinal injury in rats following gut ischemia/ reperfusion,burn,and acute necrotizing pancreatitis (ANP). METHODS Three models were developed in rats:① gut ischemia/ reperfusion obtained by one hour of superior mesenteric artery occlusion followed by reperfusion;② severe burn injury created by 30% of total body surface area(TBSA)full-thickness scald burn;and ③ ANP induced by continuous inverse infusion of sodium taurocholate and trypsin into main pancreatic duct. Plasma levels of D(-)-lactate in systemic circulation and LPS in portal circulation were measured by enzymatic- spectrophotometric method and limulus amebocyte lysate (LAL)test kit,respectively.Tissue samples of intestine were taken for histological analysis. RESULTS One hour gut ischemia followed by reperfusion injuries resulted in a significant elevation in plasma D(-)- lactate and LPS levels,and there was a significant correlation between the plasma D(-)-lactate and LPS(r =0.719,P<0.05).The plasma concentrations of D(-)- lactate and LPS increased significantly at 6h postburn, and there was also a remarkable correlation between them (r = 0.877,P < 0.01).D(-)-lactate and LPS levels elevated significantly at 2h after ANP,with a similar significant correlation between the two levels(r = 0.798, P < 0.01 ).The desquamation of intestine villi and infiltration of inflammatory cells in the lamina propria were observed in all groups. CONCLUSION The changes of plasma D(-)-lactate levels in systemic blood paralleled with LPS levels in the portal vein blood.The measurement of plasma D(-)-lactate level may be a useful marker to assess the intestinal injury and to monitor an increase of intestinal permeability and endotoxemia following severe injuries in early stage.
基金funding from the National Basic Research Program of China (2013CB127603 and 2012CB124705)the National Natural Science Foundation of China (31572414 and 30901036)the Natural Science Foundation of Jiangsu Province, China (BK20130058)
文摘D-Lactate-utilizing bacteria play important roles in maintaining the balance of gut lactate; however, studies on gut D-lactate-uti-lizing bacteria have been limited. This study aimed to isolate and identify D-lactate-utilizing bacteria from pig gut using the Hungate rol-tube method, and to investigate their metabolic characteristicsin vitro. Six different anaerobes were isolated from pig feces, which were identiifed as related toBacteroides fragilis, Bacteroides acidifaciens,Veilonela denticariosi, Veilonela caviae,Bacteroides uniformis, andMegasphaera elsdenibased on the 16S rRNA gene sequences. Al strains had a signiifcant ability to utilize D-lactate, which was concluded afterin vitro fermentation with 25 mmol L–1 D-lactate as the primary carbon source. Of al 6 strains,M. elsdeniJ6 showed the highest efifciency of D-lactate utilization and produced a higher ratio of butyrate in total short chain fatty acids （SCFAs）. Thus, thein vitro fermentation characteristics of this strain in D-, L-, and DL-lactate mixtures （D-lactate：L-lactate=1：1 or 1：2） were further studied. The results showed that M. elsdeni J6 preferred utilizing D-lactate, and produced more SCFA when using D-lactate as the primary carbon source. The ifndings suggest that the administration of D-lactate-utilizing bacteria such asM. elsdeni J6 may have a potential advantage in the aleviation of D-lactic acidosis in the animal gut.
基金supported in part by grants from the National Key Program for Fundamental Research and Development(973 Project,Grant No.G1999054203)National Natural Science Outstanding Youth Foundation(Grant No.30125020)the National Natural Science Foundation(Grant No.39870286,30200293)of China.
文摘Objective To study the potential role of tumor necrosis factor-α (TNF-α) induction in the development of mucosal barrier dysfunction in rats caused by acute intestinal ischemia-reperfusion injury, and to examine whether pretreatment with monoclonal antibody against TNF-α (TNF-α MoAb) would affect the release of D(-)-lactate after local gut ischemia followed by reperfusion. Methods Anesthetized Sprague-Dawley rats underwent superior mesenteric artery occlusion for 75 min followed by reperfusion for 6 hr. The rats were treated intravenously with either TNF-α MoAb (20 mg/kg) or albumin (20 mg/kg) 30 min prior to the onset of ischemia. Plasma D(-)-lactate levels were measured in both the portal and systemic blood by an enzymatic spectrophotometric assay. Intestinal TNF-αmRNA expression as well as protein levels were also measured at various intervals. In addition, a postmortem examination was performed together with a macropathological evaluation based on a four-grade scoring system.Results Intestinal ischemia resulted in a significant elevation in D(-)-lactate levels in the portal vein blood in both the control and treatment groups ( P ＜0.05). However, animals pretreated with TNF-α MoAb at 6 hr after reperfusion showed significant attenuation of an increase in both portal and systemic D(-)-lactate levels when compared with those only receiving albumin (P ＜ 0.05). In the control animals, a remarkable rise in intestinal TNF-α level was measured at 0.5 hr after clamp release ( P ＜ 0.01); however, prophylactic treatment with TNF-α MoAb completely annulled the increase of local TNF-α levels seen in the control animals. Similarly, after anti-TNF-α MoAb administration, intestinal TNF-α mRNA expression was markedly inhibited, which showed significant differences when compared with the control group at 0.5 hr, 2 hr and 6 hr after the release of occlusion ( P ＜ 0.05-0.01 ). In addition, the pathological examination showed marked intestinal lesions that formed during ischemia, which were much worse upon reperfusion,particularly at the 6 hr time point. These acute injuries were obviously attenuated in animals receiving TNF-α MoAb.Conclusions It appeared that acute intestinal ischemia was associated with failure of the mucosal barrier, resulting in increased plasma D(-)-lactate levels in both portal and systemic blood. These results suggest that TNF-α appears to be involved in the development of local damage associated with intestinal ischemic injury. Moreover, prophylactic treatment with TNF-α MoAb exerts preventive effects on ischemia/ reperfusion-induced circulating D (-)-lactate elevation and gut injury. ( J Geriatr Cardiol 2004;1(2):119-124. )
