Enhanced pyruvic acid yield in an osmotic stress-resistant mutant of Yarrowia lipolytica

BACKGROUND: Pyruvic acid (PA), a vital α-oxocarboxylic acid, plays an important role in energy and carbon metabolism. The oleaginous yeast Yarrowia lipolytica (Y. lipolytica) has considerable potential for the production of PA. An increased NaCl concentration reportedly increases the biomass and PA yield of Y. lipolytica. RESULTS: To increase the yield of PA, the NaCl-tolerant Y. lipolytica A4 mutant was produced using the atmospheric and room temperature plasma method of mutation. The A4 mutant showed growth on medium containing 160 g/L NaCl. The PA yield of the A4 mutant reached 97.2 g/L at 120 h (0.795 g/g glycerol) in a 20-L fermenter with glycerol as the sole carbon source, which was 28.9% higher than that of the parental strain. CONCLUSION: The PA yield from Y. lipolytica can be improved by increasing its NaCl tolerance.

Effect of pyruvate peritoneal resuscitation on JAK/STAT signaling pathway in intestinal tissues of rats with hemorrhagic shock / 中华麻醉学杂志

Objective To evaluate the effect of pyruvate peritoneal resuscitation on Janus kinase (JAK) /signal transducer and activator of transcription (STAT) signaling pathway in intestinal tissues of rats with hemorrhagic shock.Methods Twenty-four healthy male Sprague-Dawley rats,weighing 200-300 g,were divided into 3 groups (n=8 each) using a random number table method:sham operation group (S group),intravenous resuscitation group (VR group),and peritoneal resuscitation with pyruvate group (PY group).Hemorrhagic shock was induced by blood-letting and infusing blood withdrawn with mean arterial pressure reduced to 30-40 mmHg for 60 min in pentobarbital-anesthetized rats.Hemorrhagic shock was resuscitated with autologous blood and normal saline 2 times the volume of blood withdrawn at the end of hemorrhagic shock in group VR.Pyruvate was intraperitoneally infused for 30 min using a micro-perfusion pump simultaneously with the intravenous resuscitation in group PY.The animals were sacrificed at 2 h after resuscitation,and intestinal tissues were obtained for determination of malondialdehyde (MDA) content (by thiobarbituric acid method),superoxide dismutase (SOD) activity (using xanthine oxidase method),myeloperoxidase (MPO) activity (using chemical colorimetry),and expression of phosphorylated STAT3 (pSTAT3),phosphorylated JAK2 (p-JAK2) and caspase-3 expression (by Western blot).Results Compared with group S,the MDA content and MPO activity were significantly increased,the SOD activity was decreased,and the expression of p-STAT3,p-JAK2 and caspase-3 was up-regulated in the other two groups (P＜0.05).Compared with group VR,the MDA content and MPO activity were significantly decreased,the SOD activity was increased,and the expression of p-STAT3,p-JAK2 and caspase-3 was down-regulated in group PY (P＜0.05).Conclusion The mechanism by which peritoneal resuscitation with pyruvate mitigates intestinal damage may be related to inhibiting activation of JAK/STAT signaling pathway in the rats with hemorrhagic shock.

Comparison of different concentrations of pyruvate-based peritoneal dialysis solution for peritoneal resuscitation in a rat model of hemorrhagic shock / 中华麻醉学杂志

Objective To compare the efficacy of different concentrations of pyruvate-based peritoneal dialysis solution for peritoneal resuscitation in a rat model of hemorrhagic shock.Methods Forty SPF healthy male Sprague-Dawley rats,weighing 200-250 g,were assigned to 4 groups (n=10 each) using a random number table method:sham operation group (S group),routine Ⅳ resuscitation group (VR group),and intraperitoneal resuscitation with different concentrations of pyruvate-based peritoneal dialysis solution groups (PY1 group,PY2 group).The animals were anesthetized with pentobarbital sodium 400 mg/kg.Hemorrhagic shock was induced by withdrawing blood from the left femoral artery until mean arterial pressure (MAP) was reduced to 30-40 mmHg and maintained for 60 min,and the animals were then resuscitated by infusion of shed blood.In VR group,hemorrhagic shock was resuscitated by retransfusion of autologous blood and with normal saline 2 times the volume of blood loss at 1 h after hemorrhagic shock.Routine Ⅳ resuscitation was performed,and 40 and 80 mmol/L peritoneal dialysis solution 20 ml were intraperitoneally infused for 30 min at the same time in PY1 and PY2 groups,respectively.MAP was recorded before blood-letting (T0),at 5,30 and 60 min of shock (T1-3) and 5,30,60,90 and 120 min after the end of resuscitation (T4-8).Blood samples were collected at T8 for blood gas analysis,and pH value,partial pressure of oxygen (PaO2),partial pressure of carbon dioxide (PaCO2),base excess (BE),and bicarbonate ion concentration (HCO3-) were recorded.Results Compared with S group,MAP was significantly decreased at T1-8 in VR and PY1 groups and at T1-7 in PY2 group,and pH value,PaO2,BE and HCO3-were significantly decreased,and PaCO2 was increased in VR group (P＜0.05).Compared with VR group,MAP at T4-8,pH value,PaO2,BE and HCO3-were significantly increased,and PaCO2 was decreased in PY1 and PY2 groups (P＜0.05).Compared with PY1 group,MAP at T6-8 and pH value were significantly increased (P＜0.05),and no significant change was found in PaO2,PaCO2,BE or HCO3-in PY2 group (P＞0.05).Conclusion Peritoneal resuscitation with 80 mmol/L pyruvate-based peritoneal dialysis solution produces better efficacy than 40 mmol/L in a rat model of hemorrhagic shock.

Application of rhodamine-based fluorescent molecular probes in visualization of cellular pyruvic acid / 中国药科大学学报

In order to conduct the visualized research of cellular pyruvic acid(PA),several rhodamine-based probes were designed to react with PA by a Schiff-base reaction in aqueous media and exhibit strong fluorescence emission and a pink color owing to the ring-opening of the corresponding spirolactam.The results showed that R6G-NH2had a highest sensitive response to PA with a linearly relationship between the enhancement of fluores-cence intensity at 565 nm and the concentration of PA from 0.2 μmol/L to 120 μmol/L.According to the princi-ple of 3σ,a limit of detection was obtained as low as 0.1 μmol/L.Furthermore,the response of R6G-NH2to PA was hardly affected by conventional biomolecules and ionic species.Therefore,R6G-NH2was successfully used in fluorescence imaging of exogenous PA in non-small cell lung cancer cell A549 and renal epithelial cell 293T,and endogenous PA induced by bisphenol A in epithelial cell 293T.

Effect of peritoneal resuscitation with pyruvate-based peritoneal dialysis solution on liver injury in a rat model of hemorrhagic shock / 中华麻醉学杂志

Objective To evaluate the effect of peritoneal resuscitation (PR) with pyruvate-based peritoneal dialysis solution (PDS) on liver injury in a rat model of hemorrhagic shock.Methods Fifty healthy male Sprague-Dawley rats,weighing 200-250 g,were used in this study.The animals were anesthetized with pentobarbital sodium,tracheostomized and mechanically ventilated.Hemorrhagic shock was induced by withdrawing blood from the left femoral artery at a rate of 0.6 ml/min within 10 min until mean arterial pressure (MAP) was reduced to 30-40 mmHg which was maintained for 60 min.The animals were divided into 5 groups (n =10 each) using a random number table:sham operation group (group SH),conventional Ⅳ resuscitation group (group CVR),PR with normal saline group (group NS),PR with lactate-based PDS group (group LA) and PR with pyruvate-based PDS group (group PY).The animals only underwent surgical procedure in gronp SH.In group CVR,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss) via the right femoral artery after successful establishment of hemorrhagic shock.In NS,LA and PY groups,conventional resuscitation was performed,and the animals were simultaneously resuscitated with normal saline,2.5％ glucose-based PDS containing lactate,and 2.5％ glucose-based PDS containing pyruvate 20 ml,respectively.The blood withdrawn and fluid for resuscitation were all infused over 30 min.MAP was recorded before blood letting,at 5,30 and 60 min of shock and at 5,30,60,90 and 120 min after the end of resuscitation.The arterial blood lactate level was measured by chemical colorimetry at 120 min after the end of resuscitation.The animals were then sacrificed and livers were removed for examination of the pathological changes with a light microscope.The damage to livers was assessed and scored.Results Compared with MAP before blood letting,MAP was significantly decreased during hemorrhagic shock and increased at each time point after resuscitation in CVR,NS,LA and PY groups (P＜0.05).Compared with group SH,MAP during hemorrhagic shock and at each time point after resuscitation was significantly decreased,and the arterial blood lactate level and liver damage scores were increased in CVR,NS,LA and PY groups (P＜0.05).Compared with CVR and NS groups,the arterial blood lactate level and liver damage scores were significantly decreased in LA and PY groups (P＜0.05).There was no significant difference in the arterial blood lactate level or liver damage scores between group CVR and group NS (P＞0.05).Compared with group LA,the arterial blood lactate level and liver damage scores were significantly decreased in group PY (P＜0.05).Conclusion PR with pyruvate-based PDS can reduce liver injury in a rat model of hemorrhagic shock.

Effect of peritoneal resuscitation with pyruvate-based peritoneal dialysis solution on kidney injury in a rat model of hemorrhagic shock / 中华麻醉学杂志

Objective To evaluate the effect of peritoneal resuscitation (PR) with pyruvate-based peritoneal dialysis solution (PDS) on kidney injury in a rat model of hemorrhagic shock.Methods Fifty healthy adult male Sprague-Dawley rats,weighing 200-250 g,aged 8 weeks,were divided into 5 groups (n=10 each) using a random number table:sham operation group (group SH),conventional Ⅳ resuscitation group (group VR),PR with normal saline group (group NS),PR with lactate-based PDS group (group LA) and PR with pyruvate-based PDS group (group PY).Hemorrhagic shock was induced by withdrawing blood from the left femoral artery at a rate of 0.6 ml/min about 10 min until mean arterial pressure was reduced to 30-40 mmHg which was maintained for 1 h.In group VR,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss) at 1 h after hemorrhagic shock.In NS,LA and PY groups,conventional Ⅳ resuscitation was performed,and the animals were simultaneously resuscitated with normal saline,lactate-based PDS,and pyruvatebased PDS 20 ml infused intraperitoneally over 30 min,respectively.The animals were sacrificed at 180 min after resuscitation,and kidneys were removed for examination of the pathological changes (with a light microscope) and for measurement of the content of malondialdehyde (MDA) and activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) in renal tissues.The damage to renal tubules was assessed and scored.Results Compared with group SH,the renal tubular damage scores,MDA content and MPO activity were significantly increased,and the activity of SOD was decreased in the other four groups (P＜0.05).Compared with group VR,the renal tubular damage scores,MDA content and MPO activity were significantly decreased,and the activity of SOD was increased in NS,LA and PY groups (P＜0.05).Compared with group NS or group LA,the renal tubular damage scores,MDA content and MPO activity were significantly decreased,and the activity of SOD was increased in group PY (P＜0.05).The pathological changes of renal tissues were significantly attenuated in group PY when compared with VR,NS and LA groups.Conclusion PR with pyruvate-based PDS can reduce kidney injury in a rat model of hemorrhagic shock.

The effects of sodium pyruvate Ringer solution on hemodynamic and organ functions during shock stage in dogs with a 50％ total body surface area full-thickness burn / 中华危重病急救医学

Objective To compare the effect of intravenous resuscitation with sodium pyruvate (Pyr) Ringer solution against lactated Ringer solution on hemodynamic and organ functions during shock stage in dogs with burn.Methods 28 Beagle dogs were subjected to 50％ total body surface area (TBSA) burn,and they were divided into three groups:burn injury without fluid resuscitation (N R,n =8),Ringer lactate solution(RL,n =10),and Pyr Ringer solution (RP,n =10).They were given intravenous fluid resuscitation according to Parkland formula 30 minutes after burn.The hemodynamics,organ functions and mortality were observed in conscious state before burn injury,and 2,6,8,12,24 hours after burn injury.Results Within 24 hours after burn,all the dogs in NR group died,and those in RL and RP groups were all alive.At 2 hours after burn,the mean arterial pressure (MAP),cardiac index (CI),dp/dt max of left ventricular contractility were significantly reduced in NR,RL and RP groups compared with those before injury [MAP(mmHg,1 mmHg =0.133 kPa):45.33 ± 7.78 vs.141.67 ± 5.98,91.33 ± 10.25 vs.142.33 ± 6.16,98.67 ± 9.54 vs.142.83 ±5.47; CI (mL·s-1·m-2):8.17 ±0.83 vs.48.34 ±3.33,16.84 ±2.17 vs.47.34 ± 1.67,19.00 ± 1.50 vs.47.34 ± 1.33; dp/dt max (mmHg/s):426.83 ± 51.91 vs.1 372.50 ± 39.61,594.00 ± 88.23 vs.1 363.83 ± 44.92,645.00 ±66.82 vs.1 395.83 ± 19.49,all P＜0.05],and the systemic vascular resistance (SVR) and alanine transaminase (ALT),creatinine (Cr),serum MB isoenzyme of creatine kinase (CK-MB),diamine oxidase (DAO) were significantly higher [SVR (kPa·s ·L-1):1 322.50 ±36.37 vs.281.45 ± 8.84,777.50 ±41.84 vs.289.72 ± 6.70,571.40 ±40.01 vs.286.27 ±8.66; ALT (U/L):89.50 ±4.11 vs.40.57 ±3.63,89.25 ±4.88 vs.37.92 ± 2.62,86.30 ±5.61 vs.38.47 ±3.50; Cr (μmol/L):75.62 ±4.61 vs.41.58 ±2.78,77.00 ±5.92 vs.46.55 ± 3.17,74.13 ±2.56 vs.45.65 ± 1.83; CK-MB (kU/L):13.122 ±0.282 vs.1.557 ±0.009,8.885 ±0.272 vs.1.497 ± 0.009,8.692 ± 0.180 vs.1.490 ± 0.005; DAO (kU/L):2.26 ± 0.14 vs.0.25 ± 0.02,1.50 ± 0.07 vs.0.25 ± 0.01,1.37 ± 0.07 vs.0.25 ± 0.02,all P＜0.05].All parameters in NR group kept on worsening till death,while hemodynamic and organ functions of two intravenous resuscitation groups were gradually improved,CI,SVR and DAO in RP group were significantly superior to those of RL group from 2 hours on after burn (all P＜0.05),and dp/dt max and CK-MB in RP group were significantly better than those of RL group from 6 hours on after burn [dp/dt max (mmHg/s):1 082.33 ± 63.59 vs.1 018.60 ± 47.36,CK-MB (U/L):7 898.70 ± 255.74 vs.8 438.70 ± 442.00,all P＜0.05],and MAP (mmHg) was significantly better than that of RL group at 6 hours (124.67 ± 9.39 vs.114.33 ± 9.16,P＜0.05),and Cr (tμmol/L) was significantly better than that of RL group from 24 hours on after burn (53.42 ± 4.99 vs.60.77 ± 3.11,P＜0.05).Conclusion The Pyr Ringer solution was superior to the Ringer lactate solution in improving hemodynamic and organ functions for intravenous resuscitation in dogs with 50％TBSA full thickness burn.

Determination of ethyl pyruvate in chitosan nanoparticles by reversed-phase high-performance liquid chromatography / 中国组织工程研究

BACKGROUND:Research on ethyl pyruvate detection methods is reported rarely, and moreover, literature about reversed-phase high-performance liquid chromatography (RP-HPLC) for detection of ethyl pyruvate is less. OBJECTIVE:To establish an RP-HPLC method for determination of ethyl pyruvate in ethyl pyruvate-chitosan nanoparticles. METHODS: The chromatographic analysis was performed on a ZORBAX Eclipse XDB-C18 column (4.6 mm× 150 mm, 5μm) at 25℃, with the mixture of acetonitrile and water (40:60, V/V) as the mobile phase at the flow rate of 1 mL/min. The determination wavelength wasset at 210 nm and the injection volume was 20 μL. RESULTS AND CONCLUSION: The peak of ethyl pyruvate and the peaks of auxiliary materials and solvent were separated wel. The linear rang of ethyl pyruvate was 1-100 mg/L (r=0.999 6). The relative standard deviation of both the intra-and inter-day precision was less than 3% for low-, moderate-, and high-concentration ethyl pyruvate. The relative standard deviation of reproducibility test and stability test was 1.25% and 1.3%, respectively. Sample average recovery rates were (91.5±1.0)%, (3.5±0.2)%, (94.4±0.4)%, respectively. Encapsulation efficiency of samples were (87.2±0.22)%, (90.5±0.15)%, (91.1±0.17)%, respectively. The relative standard deviation of different sample content were 0.9%, 0.5%, 0.3%, respectively. The RP-HPLC method for determination of ethyl pyruvate is sensitive, accurate and highly specific with wide linear range and high sample average recovery.

Ethyl-pyruvate reduces lung injury matrix metalloproteinases and cytokines and improves survival in experimental model of severe acute pancreatitis

PURPOSE: To investigate if the ethyl-pyruvate solution could reduce mortality in AP and/or diminish the acute lung injury. METHODS: Forty male rats, weighing between 270 to 330 grams were operated. An experimental model of severe AP by injection of 0.1ml/100g of 2.5% sodium taurocholate into the bilio-pancreatic duct was utilized. The rats were divided into two groups of ten animals each: CT - control (treatment with 50ml/kg of Ringer's solution, intraperitoneal) and EP (treatment with 50ml/kg of Ringer ethyl- pyruvate solution, intra-peritoneal), three hours following AP induction. After six hours, a new infusion of the treatment solution was performed in each group. Two hours later, the animals were killed and the pulmonary parenchyma was resected for biomolecular analysis, consisting of: interleukin, myeloperoxidase, MDA, nitric oxide, metalloproteinases and heat shock protein. In the second part of the experiment, another, 20 rats were randomly divided into EP and CT groups, in order to evaluate a survival comparison between the two groups. RESULTS: There were no significant differences in IL-1B,IL-10, MMP-9, HSP70, nitric oxide, MPO, MDA (lipidic peroxidation) concerning both groups. The levels of IL-6 were significantly diminished in the EP group. Furthermore, the MMP-2 levels were also reduced in the EP group (p<0.05). The animals from the EP treatment groups had improved survival, when compared to control group (p<0.05). CONCLUSION: The ethyl-pyruvate diminishes acute lung injury inflammatory response in acute pancreatitis and ameliorates survival when compared to control group, in the experimental model of necrotizing acute pancreatitis.

Effects of direct peritoneal resuscitation with sodium pyruvate from hemorrhagic shock on intestinal injury in rats / 中华麻醉学杂志

Objective To investigate the effects of direct peritoneal resuscitation (DPR) with sodium pyruvate from hemorrhagic shock (HS) on intestinal injury in rats.Methods Fifty SPF male Sprague-Dawley rats,weighing 200-250 g,were used in this study.The animals were anesthetized with 1％ pentobarbital sodium 40 mg/kg,tracheostomized and mechanically ventilated.Femoral artery was cannulated for mean arterial pressure (MAP) monitoring,blood-letting,blood sampling and fluid infusion.HS was induced according to the method described by Wiggers.MAP was maintained at 35-40 mm Hg for 60 min.The animals were then randomly and equally divided into 5 groups:sham operation group (group S) ; conventional resuscitation group (group CR) ; DPR with different fluid groups (DPRt-3 groups).In group CR,at 1 h after HS,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss).In DPR1-3 groups,conventional resuscitation was performed,at the same time,1.5 ％ glucose-based peritoneal dialysis solution containing lactate,1.5％ glucose-based peritoneal dialysis solution containing lactate (40.00 mmol/L),and 1.5％ glucosebased peritoneal dialysis solution containing high lactate (80.00 mmol/L) 20 ml were infused intraperitoneally over 30 min,respectively.MAP was recorded before blood letting,at 5,30 and 60 min of HS,and at 5,30,60,90 and 120 min after the end of resuscitation.At 120 min after the end of resuscitation,the lactate level in the arterial blood was measured.The animals were then sacrificed.Small intestinal samples were obtained for determination of malondialdehyde (MDA) content,myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) expression,and for microscopic examination.The damage to the small intestinal mucosa was assessed and scored.Results Compared with MAP before blood letting,MAP during HS was significantly decreased,and no significant change in MAP was found after resuscitation in CR and DPR1-3 groups (P ＜ 0.05).The lactate level in the arterial blood,MDA content,MPO activity,TNF-α expression and intestinal mucosal damage scores were significantly higher in CR and DPR1-3 groups than in S group (P ＜ 0.05 or 0.01),while lower in DPR1-3 groups than in CR group (P ＜0.01),and in DPR2,3 groups than in DPR1 group (P ＜ 0.05 or 0.01).The lactate level in the arterial blood,MDA content and TNF-α expression were significantly lower in DPR3 group than in DPR2 group (P ＜ 0.05 or 0.01).Conclusion Direct peritoneal resuscitation with sodium pyruvate can reduce the intestinal injury induced by HS and inhibition of lipid peroxidation and inflammatory responses is involved in the mechanism in rats.

Diagnosis value of minimum exercise test of lactic acid and pyruvic acid for mitochondrial myopathy / 临床神经病学杂志

17.The abnormal results of METLP were found in 6(100%) patients with other myopathy.Most of them showed a high concentration of lactic acid post-aerobic exercise(L2),and sustainable to after rest,or even more higher(L3).3(21.4%)patients without myopathy showed abnormal results of METLP.Conclusions In all the indexes of METLP,the value of L2/P1 is the reliable index for diagnosis mitochondrial myopathy or no-myopathy;the value of L3/L2 is the most important index in differential diagnosis of mitochondrial myopathy and other myopathy.METLP plays a certain role in the diagnosis of the mitochondrial myopathy,but the clinical and pathological data ought to be combined.