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reduced to 30-40 mmHg which was maintained for 1 h.In group VR,the animals were resuscitated with infusion of the blood withdrawn and normal saline (the volume was 2 times volume of blood loss) at 1 h after hemorrhagic shock.In NS,LA and PY groups,conventional Ⅳ resuscitation was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.

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.

Objective:To evaluate the relationship between the over-expression of endocannabinoid receptor 2 (CB2R) and macrophage pyroptosis in mice.Methods:Bone marrow-derived macrophages of mice were transfected by lentivirus vector and successfully screened out two stable cell lines: lentivirus LV5 negative control cells (LV5-NC) and lentivirus LV5CB2R overexpressing cells (OE). Two cell lines were respectively divided into 3 groups ( n=18 each) using a random number table method: control group (LV5-NC-C group, OE-C group), LPS/ATP group (LV5-NC-LPS/ATP group, OE-LPS/ATP group) and CB2R specific agonist HU308 group (LV5-NC-HU308 group, OE-HU308 group). Cells in group C were commonly cultured.In LPS/ATP group, cells were incubated with LPS at a final concentration of 0.5 μg/ml for 5 h, and then incubated with ATP at the final concentration of 5 mmol/L for 1 h. In group LPS/ATP+ HU308, cells were incubated for 5 h with LPS at the final concentration of 0.5 μg/ml and HU308 at the final concentration of 10 μmol/L and then with ATP at the final concentration of 5 mmol/L for 1 h. The expression of CB2R, nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3), caspase-1, and gasdermin D (GSDMD) mRNA was detected by real-time polymerase chain reaction, the expression of caspase-1 was detected by Western blot, and the concentrations of interleukin-18 (IL-18) and IL-1β in the culture medium were determined by enzyme-linked immunosorbent assay. Results:In each cell line, compared with group C, the expression of NLRP3, caspase-1 and GSDMD was significantly up-regulated, and the concentrations of IL-18 and IL-1β were increased in group LPS/ATP ( P<0.05). Compared with group LPS/ATP, the expression of NLRP3, caspase-1 and GSDMD was significantly down-regulated, the concentrations of IL-18 and IL-lβ were decreased in group HU308 ( P<0.05). There was no significant differences in the indicators mentioned above between group V5-NC-C and group OE-C, between group LV5-NC-LPS/ATP and group OE-LPS/ATP, and between group LV5-NC-HU308 and OE-HU308 ( P>0.05). Conclusion:Over-expression of CB2R gene cannot effectively inhibit the occurrence of macrophage pyroptosis, and only activation of CB2R can inhibit it in mice.

Objective To evaluate the effect of continuous low-to medium-flow oxygen administration in non-ventilated lung on the oxidative stress response of lung tissues during one-lung ventilation (OLV).Methods Fifty-seven American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients,aged 50-64 yr,weighing 40-74 kg,scheduled for elective pulmonary tumorectomy,were divided into 2 groups using a random number table:control group (group C,n=29) and continuous oxygen administration group (group O,n =28).The patients were intubated with the double-lumen tube after induction of anesthesia.Correct position of the tube was verified with the fiberoptic bronchoscope.In group O,the F14 tube was placed at 2-3 cm beyond the carina of trachea in the non-ventilated lung at the beginning of OLV,and low-to medium-flow oxygen was continuously administered at 1-4 L/min with the fractional concentration of inspired oxygen set at 25％-37％.Blood samples were taken from the radial artery and internal jugular bulb at the beginning of anesthesia induction (T1) and 30 min,1 h and 2 h of OLV (T2-4) for blood gas analysis.Lung tissues at the site 5 cm lateral to the tumor were taken immediately after resection of diseased tissues for determination of superoxide dismutase and malondialdehyde levels (by chemical colorimetry) and heme oxygenase-1 expression (by Western blot).Results Compared with group C,the partial pressure of arterial oxygen was significantly increased at T2-4,the partial pressure of arterial carbon dioxide was decreased at T2,3,the partial pressure of venous oxygen was increased at T2,3,the partial pressure of venous carbon dioxide was decreased at T2-4,the malondialdehyde level was decreased,and the expression of heme oxygenase-1 was up-regulated (P＜0.05),and no significant change was found in superoxide dismutase level in group O (P＞0.05).Conclusion The mechanism by which continuous low-to medium-flow oxygen administration in non-ventilated lung exerts pulmonary protection is related to inhibiting oxidative stress responses of lung tissues during OLV.

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.

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.