BACKGROUND: Long-term radioactive ray accumulation leads to surrounding tissues fibrosis accompanied by limitation of mouth-opening, which seriously affects life quality of tumor patients. OBJECTIVE: To observe pathological change of soft tissues in rats with radiation masseter injury and the level of transforming growth factor β1 (TGF-β1) mRNA expression in vivo.METHODS: A total of 30 Wistar rats were randomly divided into control group (n=10) and radiated group (n=20). Radiated group were radiated with linear accelerator at a dose of 40 Gy. The pathological changes of vessels were observed under light microscope and electron microscope and expression of TGF-β1 was detected by RT-PCR. RESULTS AND CONCLUSION: The microvessel density of radiated group was obviously decreased than that of the control group (P < 0.01), but the mRNA expression of was higher than that in the control group (P < 0.01). It suggests that radiated injury can induce fibrosis to repair the radiated injury.

Objective To investigate the effects of emulsified isoflurane preconditioning on myocardial NF-κB activity during ischemia-reperfusion(I/R)in rats.Methods Forty-eight healthy male SD rats weighing 230-280 g were randomly divided into 4 groups with 12 animals in each group: sham operation group(group S),I/R group,lipid emulsion + I/R group(group L)and emulsified isoflurane + I/R group(group EI).In group I/R,EI and L,myocardial I/R was produced by occlusion of left coronary anterior descending artery(LAD)for 30 min followed by 120 min reperfusion.In group L,30% lipid emulsion 4 ml·kg-1 ·h-1 was infused intravenously for 30 min before myocardial I/R.In group EI,emulsified isoflurane 4 ml· kg- 1 · h- 1 was infused intravenously for 30 min followed by 15 min washout before myocardial I/R.In group S and I/R,normal saline was given instead.Blood samples were taken from femoral artery at the end of 120 min reperfusion for determination of serum cTnI and IL-6 concentrations and CK-MB activity by ELISA.The rats were then killed and the myocardial tissues were taken for determination of NF-κB activity by Western blot and observation of the ultrastructure by electron microscopy.Results The NF-κB activity,serum cTnI and IL-6 concentrations and CK-MB activity were significantly higher in group I/R,EI and L than in group S(P ＜ 0.05 or 0.01),while lower in group EI than in group I/R(P ＜ 0.05).Microscopic examination showed that emulsified isoflurane significantly attenuated the histopathological changes in group EI.Conclusion Emulsified isoflurane pretreatment can attenuate myocardial I/R injury through decreasing the NF-κB activity and inhibiting inflammatory response in rats.

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 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 evaluate the role of M3 receptor in penehyclidine hydrochloride(PHC)-induced reduction of increased permeability of human pulmonary microvascular endothelial cells (PMVECs) caused by endotoxin and the relationship with mitogen-activated protein kinase (MAPK) signaling pathway.Methods Human PMVECs were seeded in 6-well plates (2 ml/hole) or in culture flasks (4 ml/flask) at the density of 1 × 105 cells/ml and randomly divided into 6 groups (n=5 each):control group (group C),M3 receptor shRNA transfection group (group shRNA),lipopolysaccharide (LPS) group,penehyclidine plus LPS group (group P+LPS),LPS plus M3 receptor shRNA transfection group (group LPS+shRNA) and PHC plus LPS plus M3 shRNA transfection group (group P+LPS+shRNA).The cells were transfected with shRNA plasmid containing 2.5 nmol/L M3 receptors in shRNA,LPS+shRNA and P+LPS+shRNA groups.LPS at the final concentration of 0.1 μg/ml was added at 24 h of incubation and then cells were incubated for 1 h in LPS and LPS+shRNA groups.PHC at the final concentration of 2 μg/ml was added at 24 h of incubation,cells were incubated for 1 h,then LPS at the final concentration of 0.1 μg/ml was added,and cells were incubated for another l h in P+LPS and P+LPS+shRNA groups.The permeability of PMVECs was measured using Transwell assay.The expression of phosphorylated p38 MAPK (p-p38 MAPK)and phosphorylated extracellular signal-regulated protein kinase 1/2 (p-ERK1/2) was detected by Western blot,the expression of heat shock protein 27 (HSP27) using immunofluorescent staining,and the expression of M3receptor mRNA by real-time polymerase chain reaction.Results Compared with group C,M3 receptor mRNA expression was significantly down-regulated in group shRNA,and the permeability of cells was significantly increased,and the expression of p-p38 MAPK,p-ERK1/2,HSP27 and M3 receptor mRNA was up-regulated in group LPS (P＜0.05).The permeability of cells was significantly decreased,and the expression of p-p38 MAPK,p-ERK1/2,HSP27 and M3 receptor mRNA was down-regulated in P+ LPS,LPS+shRNA and P+LPS+shRNA groups as compared with group LPS,and in group P+LPS+shRNA as compared with group LPS+shRNA (P＜0.05).Conclusion The mechanism by which PHC reduces endotoxin-caused increased permeability of human PMVECs is related to inhibiting activation of MAPK signaling pathway after down-regulating M3 receptor.

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.

Objective To evaluate the role of M3 receptors in penehyclidine hydrochloride ( PHC)-induced reduction of lipopolysaccharide ( LPS)-induced injury to human pulmonary microvascular endotheli-al cells ( PMVECs) . Methods Human PMVECs transfected with M3 shRNA were seeded in 6-well plates (2 ml∕hole) or in culture flasks (4 ml∕flask) at the density of 1×105 cells∕ml and divided into 5 groups ( n=5 each) using a random number table method: control group ( group C) , LPS group, PHC plus LPS group ( group P+LPS) , LPS plus M3 shRNA transfection group ( group LPS+shRNA) , and PHC plus LPS plus M3 shRNA transfection group ( group P+LPS+shRNA) . Group C received no mediation, and LPS was added at the final concentration of 0. 1 μg∕ml in the other groups. PHC 2 μg∕ml was added at 1 h before adding LPS in P+LPS and P+LPS+shRNA groups. The cells were transfected with plasmid containing 2. 5 nmol∕L M3 receptor shRNA in LPS+shRNA group and P+LPS+shRNA group. Contents of filamentous actin ( F-actin) in endothelial cells were measured by flow cytometry at 1 h after adding LPS. The expression of myosin light chain kinase ( MLCK) and VE-cadherin protein was examined by immunofluorescence. The ex-pression of nuclear factor kappa B ( NF-κB) p65 and IκB was detected by Western blot. Contents of tumor necrosis factor-alpha ( TNF-α) and interleukin-6 ( IL-6) were determined by enzyme-linked immunosorbent assay. The M3 receptor mRNA transcription was detected by real-time polymerase chain reaction at 10, 30 and 60 min after adding LPS. Results Compared with group C, F-actin content was significantly de-creased, the expression of VE-cadherin and IκB was down-regulated, the contents of TNF-αand IL-6 were increased, and the expression of MLCK and NF-κB p65 was up-regulated in LPS and P+LPS groups ( P<0. 05) . Compared with group C, the expression of M3 receptor mRNA was significantly up-regulated in group LPS ( P<0. 05) , and no significant change was found in group P+LPS ( P>0. 05) . Compared with group LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB was up-reg-ulated, the contents of TNF-αand IL-6 were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS and group LPS+shRNA ( P<0. 05) . Compared with group P+LPS, F-actin content was significantly increased, the expression of VE-cadherin and IκB protein was up-regulated, TNF-α and IL-6 contents were decreased, and the expression of MLCK, NF-κB p65 and M3 receptor mRNA was down-regulated in group P+LPS+shRNA ( P<0. 05) . Conclusion PHC re-duces LPS-induced injury to human PMVECs through interfering with M3 receptors and inhibiting NF-κB-mediated inflammatory responses.