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Objectives To investigate the occipital cortex metabolite alterations in repetitive and severe neonatal hypoglycemia rats treated with sodium pyruvate and to reveal the protective role of sodium pyruvate using high resolution 1H nuclear magnetic resonance spectroscopy.Methods Thirty-six 2-dayold Sprague-Dawley rats were randomly divided into hypoglycemia group and pyruvate group with 18 rats in each group.Rats in both groups received intraperitoneal injections of insulin (40 U/kg body weight) at 2,4 and 6 days of age to induce severe hypoglycemia (blood glucose value ≤ 1.4 mmol/L).In the hypoglycemia group,2.5 hours after insulin injection,intraperitoneal injection of 50％ glucose (2 ml/kg) was administered to terminate hypoglycemia,while in the pyruvate group,50％ glucose (2 ml/kg) and sodium pyruvate solution 2.5 ml/kg (500 mg/kg) were injected.Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay was used to observe the status of injured neurons in six neonatal rats,and metabolite changes in occipital cortex of the other 12 rats were detected by 1H nuclear magnetic resonance spectroscopy.The difference between the two groups was compared by independent-samples t test.Results Neonatal rats of both groups reached severe hypoglycemia level 2.5 hours after insulin injection.Compared with hypoglycemia group,pyruvate group had fewer injured neurons (45±5 vs 113 ± 12,t=0.782,P=0.013) and lower injured index in the occipital cortex (0.15 ± 0.03 vs 0.36 ± 0.06,t=l.143,P=0.020).Pyruvate group showed significant decreases in the concentration of taurine [(13.31 ± 2.06) vs (18.44 ± 3.86) mol/kg,t=8.231],glutamine[(1.50 ± 0.24) vs (2.02 ± 0.40) mol/kg,t=3.137],glutamate[(7.04 ± 0.95) vs (9.40 ± 1.73) mol/kg,t=6.449],aspartate[(1.51 ± 0.28) vs (2.15 ± 0.58) mol/kg,t=2.561] and creatine [(6.37±0.99) vs (8.46± 1.77) mol/kg,t =4.226] in the occipital cortex (all P'＜0.017).Conclusions Simultaneous use of glucose and sodium pyruvate to terminate hypoglycemia in repetitive and severe neonatal hypoglycemia rats can effectively alleviate severe hypoglycemia-induced occipital lobe damage via regulating excitatory amino acid neurotransmitters,energy metabolism and other metabolic pathways.
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Objective To evaluate the effects of pyruvate Ringer' s solution on erythrocyte deformation function in the patients undergoing cardiopulmonary bypass (CPB) in vitro.Methods Thirteen patients of both sexes,aged 25-64 yr,of ASA physical status Ⅱ or Ⅲ (NAHY Ⅱ or Ⅲ),scheduled for elective cardiac valve replacement under CPB were enrolled in the study.At 10 and 60 min of CPB (T1,2) and 60 min after termination of CPB (T3),blood samples 18 ml were drawn from the radial artery and each patient's blood sample was equally divided into 6 parts (3 ml per part).The blood samples were divided into 3 groups (n =13 each):control group (group C),lactated Ringer's solution group (group R),and pyruvate Ringer's solution group (group P).In C,R and P groups,normal saline 1 ml,lactated Ringer's solution 1 ml,and pyruvate Ringer's solution 1 ml were added,respectively,and then the erythrocytes were incubated for 60 min at 37 ℃.At 30 and 60 min of incubation,the erythrocyte rigidity index (ERI) and erythrocyte deformation index (EDI) were detected.Results Compared with C and R groups,the ERI was significantly decreased at 30 and 60 min of incubation at T1,the EDI was decreased at 30 min of incubation at T1,2,and no significant change was found in ERI at T2,3 or in EDI at T3 in group P.There was no significant difference in ERI and EDI at different time points of incubation within groups.Conclusion Pyruvate Ringer's solution can enhance erythrocyte deformation function in the patients undergoing CPB.
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Objective To investigate the effects of ethyl pyruvate (EP) pretreatment on the liver injury in rats undergoing orthotopic liver transplantation (OLT).Methods Forty male adult SD rats,weighing 220-250 g,served as liver transplant donors and recipients.The recipient rats were randomly divided into 3 groups ( n =8 each):sham operation group (group S),OLT group and EP group.Group S only underwent simple laparotomy.The model of OLT was established according to the modified Kamada's two-cuff technique in groups OLT and EP.EP 40 mg/kg was injected via the caudal vein at 1 h before skin incision in group EP.Venous blood samples were taken at 2 h of neohepatic phase to determine the serum activities of alanine amino-transferase (ALT) and aspartate amino-transferase (AST).Hepatic specimens were obtained to detect the content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD).Results Compared with group S,the levels of serum ALT and AST and MDA were significantly increased and the activity of SOD was significantly decreased in groups OLT and EP ( P ＜0.05 or 0.01).The levels of serum ALT and AST and MDA were significantly lower and the activity of SOD was significantly higher in group EP than in group OLT ( P ＜ 0.05 or 0.01 ).Conclusion Ethyl pyruvate pretreatment can attenuate the liver injury in rats undergoing OLT.
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ObjectiveTo investgate the effects of pyruvate sodium on energy metabolism of erythrocytes in dog blood during circulation in cardiopulmonary bypass machine.MethodsTen healthy adult mongrel dogs of both sexes weighing 12-18 kg were anesthetized with intraperitoneal 2.5％ pentobarbital 25 mg/kg.Femoral artery was cannulated and 500 ml of blood was collected from femoral artery in each dog.Blood samples from the 10 dogs were divided into 2 equal parts (250 ml each).Each part was mixed with 250 ml lactated Ringer's solution (group C) or 250 ml pyruvate sodium (group P).Flow rate of 4 L/min was employed and blood temperature was kept at 30-32 ℃ during circulation in cardiopulmonary bypass machine.The blood sanples were collected before (baseline value,T1 ) and at 30,60,90,120 min of circulation (T2-5) for determination of ATP,ADP and AMP concentrations in RBC.ResultsThe ATP and AMP concentrations were significantly higher at T2-5,while ADP concentration was higher in group P than in group C.ConclusionPyruvate sodium can improve energy metabolism of erythrocytes in dog blood druing circulation in cardiopulmary bypass machine.
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AIM: To understand the effect of exogenous carbon substrate on the dynamic regulation of cardiac oxidative phosphorylation. METHODS: Method of mean response time measurement of the myocardial mitochondrial O 2 consumption (t mito ) was developed by van Beek. Glucose, lactate, or pyruvate as carbon substrate respectively for myocardial energy supply was perfused in isolated rabbit hearts with Tyrode solution at 37℃. RESULTS: When heart rate was stepped up from 120 to 140 and 220 (beat?min -1 ) respectively the t mito . We have measured was: (6.3?1.0) s and (7 4?0.9) s for glucose; (5.4?1.2) s and (7.0?0.9) s for lactate; (4.0?0.7)s and (6 5?0 6) s for pyruvate (two way ANOVA, P