Essentialhypertension(EH)ischaracterizedbyanincreasedtotalperipheralresistance . Therearefourtypesofpotassiumchannelsinvascularsmoothmusclecells ,includingKca ,Kv ,Kir ,KATP , whichplayanimportantroleinregulatingthediameterofvascular .Thechangeofpotassiumchannelsmay havesomethingtodowiththepathogenesisofhypertension .Thisarticlereviewsthecharactersofpotassium channelsandtheirrolesinEH . [

Objective To investigate the effect of propofol on ketamine-induced cognitive dysfunction and neuronal apoptosis in hippocampus in aged rats. Methods Thirty-two male SD rats aged 18-24 months weighing 380-470 g were randomly divided into 4 groups ( n = 8 each) :control group (group C);propofol group (group P);ketamine group (group K) and propofol + ketamine group (group PK). Propofol 30 mg·kg-1·h-1 or/and ketamine 40 mg· kg-1·h-1 were infused for 2 h once a day for 7 consecutive days. After the last day of drug administration cognitive function was assessed using Morris water maze (escape latency and the number of animals' swimming across the platform). The animals were sncrificed after water naze test and their hippocampi were removed for determination of neuronal apoptosis (by TUNEL) and caspase-3 expression (by immuno-histochemistry) in hippocampal CA1 region. Results There was no significant difference in escape latency and the number of the animals,swimming across the platform, the neuronal apoptotic rate (the number of apoptotic neurons/the number of total neurons) and caspase-3 expression between group C and P. In group K and PK the escape latency was prolonged,the number of animals' swimming across the platform was decreased, neuronal apoptotic rate increased and the caspase-3 expression up-regulated as compared with group C. The ketamine-induced changes were significantly attenuated by coadministration of propofol in group PK. Conclusion Coadministration of propofol can ameliorate ketamine-induced cognitive dysfunction and hippocampal neuronal apoptosis.

ObjectiveTo assess the effects of intra-articular Hydromorphone with Ropivacaine for postoperative analgesia after arthroscopic knee surgery.Methods 90 patients undergoing arthroscopic knee surgery were randomly divided into 3 groups. Group R: 0.375% Ropivacaine 20ml; group H1: Hydromorphone 0.3 mg and 0.375 % Ropivacaine 20 ml; group H2: Hydromorphone 0.6 mg and 0.375 % Ropivacaine 20 ml. The visual analogue scale (VAS) at rest were recorded at 6, 12, 18 and 24 h after surgery, Duration of analgesia, number of patients and frequency requiring Parecoxib at 24 h after surgery were observed.Results Compared with group R, VAS of group H1 and group H2 were signiifcantly lower at 12 and 18h after the operation, duration of analgesia was much longer, number of patients and frequency requiring Parecoxib was lower in group H1 and H2 (P < 0.05); Compared with group H1, No signiifcant differences of VAS, duration of analgesia and number of patients and frequency requiring Parecoxib of group H2.Conclusions After knee arthroscopic surgery, intra-articular 0.3 mg Hydromorphone can signiifcantly improve the efifcacy of Ropivacaine for postoperative analgesia; the efifcacy of Hydromorphone can’t increased with the increase of dosage.

ObjectiveTo investigate the effects of sevoflurane postconditioning on myocardial neutrophil infiltration in patients undergoing cardiac valve replacement under cardiopulmonary bypass (CPB).Methods Twenty-four ASA Ⅱ or Ⅲ patients (NYHA Ⅱ or Ⅲ ) of both sexes aged 20-50 yr with BMI of 19-25 kg/m2 undergoing cardiac valve replacement under CPB were randomly divided into 2 groups ( n =12 each):group control (group C) and group sevoflurane postconditioning (group S).Anesthesia was induced with midazolam,fentanyl,etomidate and rocuronium and maintained with iv infusion of fentanyl,midazolam and vecuronium.The patients were intubated and mechanically ventilated (VT 8-10 ml/kg,RR 10-14 bpm,I∶E 1∶2,FiO2 100％ ).PETCO2 was maintained at 35-40 mm Hg.In group S sevoflurane was inhaled immediately after aorta and vena cava were unclamped.The end-tidal sevoflurane concentration was maintained at 1.7％ for 5 min.Arterial blood samples were collected before surgery and at 1,2 and 4 h after aortic unclamping for determination of plasma cardiac troponin T concentration.Myocardial specimens were obtained from right auricular appendage after opening of pericardium and at 1 h after aortic unclamping for microscopic examination and determination of myocardial myeloperoxidase expression.ResultsSevoflurane postconditioning significantly decreased plasma cardiac troponin T concentration and myocardial myeloperoxidase expression and ameliorated histo-pathological damage in group S as compared with group C.ConclusionMyocardial neutrophil infiltration is involved in the protective effect of sevoflurane postconditioning against myocardial injury in patients undergoing cardiac valve replacement under CPB.

Objective To evaluate the effects of different concentrations of dexmedetomidine on large-con-ductance Ca2+-activated K+ (BKca) channels in the rat mesenteric arterial smooth muscle (MASM) cells.Methods Sprague-Dawley rats of both sexes,weighing 180-220 g,were used in this study.Single MASM cell was freshly isolated from mesenteric arteries in two steps.Ten cells were chosen and studied.When holding potential was 40 mV and the concentration of free calcium ions was 10-7 mol/L,inside-out patch-clamp technique was used to record the single BKCa channel current before and after application of different concentrations of dexmedetomidine (0,10-9,10-8,10-7,10-6,10-5 mol/L).Total open probability (NPo),amplitude (Am),mean open time (To) and mean close time (To) of single BKca channel were observed and recorded.Results Compared with the baseline value,dexmedetomidine 10-7,10-6 and 10-5 mol/L increased NPo in a concentration-dependent man-ner,and dexmedetomidine 10-9,10-8,10-7,10-6,10-5mol/L shortened Tc (P ＜0.05 or 0.01).Compared with the value obtained when the concentration of dexmedetomidine was 10-9 mol/L,Tc was significantly shortened when the concentration of dexmedetomidine was 10-8 mol/L (P ＜ 0.05),and no significant change was found in Am and To obtained when different concentrations of dexmedetomidine were applied (P ＞ 0.05).Conclusion Dexmedetomidine 10-7,10-6 and 10-5 mol/L activate BKca channels in rat MASM cells in a concentration-depen-dent manner,which is one of the mechanisms of decrease in blood pressure by dexmedetomidine.

Objective To investigate the effects of hydrogen inhalation on the brain injury after intestinal ischemia/reperfusion (I/R) in rats.Methods Fifty-four healthy male Sprague-Dawley rats aged 6-8 months,weighing 285-350 g,were randomly allocated to one of 3 groups (n =18 each):sham operation group (group S),intestinal I/R group (group I/R) and hydrogen inhalation group (group H2).Intestinal I/R was produced by occlusion of the superior mesenteric artery for 90 min followed by reperfusion.2％ hydrogen was inhaled for 3 h starting from the end of ischemia.The cognitive function was detected at 1,2 and 5 days of reperfusion using Morris water maze test.The animals were sacrificed after the test and brains were isolated for detection of the cerebral edema and morphology in brain tissues.The cerebral water content ((wet weight-dry weight)/ wet weight × 100％) was measured.The pathological changes in the prefrontal cortex was observed under light microscope.The neuronal apoptosis was detected by TUNEL.Results Compared with the S group,the number of normal neurons in the prefrontal cortex was significantly decreased,the latency and swimming distance were both prolonged,the frequency of crossing the original platform was decreased,and the cerebral water content and the number of apoptotic neurons were increased in groups I/R and H2 (P ＜ 0.05).Compared with I/R group,the number of normal neurons in the prefrontal cortex was significantly increased,the latency and swimming distance were both shortened,the frequency of crossing the original platform was increased,the cerebral water content and the nunber of apoptotic neurons were decreased in group H2 (P ＜ 0.05).The pathological changes were obvious in I/R group,however,they were significantly attenuated in H2 group.Conclusion H2 inhalation can reduce the brain damage and improve the cognitive dysfunction after intestinal I/R in rats.

Objective To investigate the effects of hydrogen gas inhalation on cerebral oxidative stress and inflammation after intestinal ischemia/reperfusion (I/R) in rats and to understand the mechanism of(I/R neuroprotection.Method Forty-eight healthy male SD rats weighing 285-350 g were randomly allocated to one of 3 groups (n =16 each group):sham operation group (Sham),intestinal I/R group (I/R) and intestinal IR plus hydrogen gas inhalation group (IR + H2).The I/R model was produced by occlusion of superior mesenteric artery (SMA) for 90 min followed by reperfusion.Inhalation of 2％ hydrogen gas was performed immediately after I/R for 3 h.All animals were sacrificed at 24 h after reperfusion in each group.Brain tissues of 8 animals in each group were harvested for detection of microglia by immunohistochemistry.The remaining 8 rats in each group were used for the following indicators analysis.The protein level of ionized calcium-binding adaptor molecular 1 (Iba-1,a marker of microglia) in the cortex was detected by Western blotting.The concentrations of ROS,MDA,IL-1β,IL-6,TNF-α,T-NOS,iNOS and NO in the cortex were measured.The MPO content and SOD activity were also measured.Result The Iba-1 staining was light in Sham group.However,the expression of Iba-1 was increased in I/R group,and H2 inhibited the expression of Iba-l.As compared with Sham group,the Iba-1 protein expression and the number of Iba-1 positive cells were increased significantly in I/R and I/R+ H2groups (P＜0.01 or 0.05).As compared with Sham group,ROS,MDA,IL-1β,IL-6,TNF-α,T-NOS,iNOS and NO levels,and MPO activity were also increased in I/R and I/R + H2groups (P＜0.01 or 0.05).As compared with I/R group,the above indicators in I/R + H2 group were markedly improved (P＜0.05 or 0.01).Conclusion The inhalation H2 could inhibit intestinal I/R-induced activation of microglia and reduce cerebral oxidative stress and inflarnmatory response in rats.

Objective To evaluate the effectiveness of mouth care combined with intestinal and endoscopic working channel washing for ERCP related cholangitis.Methods A total of 573 patients diagnosed as having obstructive jaundice were randomized into three groups,190 cases in the control group,192 in the saline group and 191 in the amikacin group.Clinical and laboratory data were collected before ERCP and ERCP related cholangitis were recorded.Results There were no significant differences among the three groups in sex,age,the level of obstruction,the category of obstruction,total bilirubin or WBC counting.The incidences of ERCP related cholangitis were 21.1％ (40/190),13.5％ (26/192) and 4.7％ (9/191)in control group,saline group and amikacin group respectively,which was significantly different (x2 =22.409,P =0.000 ).The incidences of ERCP related cholangitis were 19.5％ ( 65/333 ) and 4.2％(10/240) in patients diagnosed as having hilar duct obstruction and low positioned biliary obstruction respectively (x2 =27.175,P =0.000).There was no significant difference in ERCP related cholangitis between benign and malignant biliary obstruction.Subgroup of hilar duct obstruction showed the incidences of ERCP related cholangitis were 29.7％ (33/111 ),20.5％ (24/117)and 7.6％ (8/105)in the control group,the saline group and the amikacin group,respectively (x2 =16.905,P =0.000).Conclusion The incidence of ERCP related cholangitis is relatively higher in patients with hilar duct obstruction.Mouth care combined with intestinal and endoscopic working channel washing can effectively reduce the incidence of ERCP related cholangitis,especially in the amikacin group.

Objective To investigate the role of large-conductance Ga2+-activated K+ (BKCa) channels and protein kinase G (PKG) in ketamine-induced isolated tracheal smooth muscle relaxation in rats with asthma.Methods Healthy Sprague-Dawley rats,weighing 250-300 g,were used in this study.Asthma was induced with egg albumin.Thirty-six tracheal rings of 15 rats in which asthma model was successfully established were randomly divided into 3 groups (n =12 each):ketamine treatment group (group AK),IBTX (BKCa channel blocker) +ketamine treatment group (group AKI),and KT-58232 (PKG inhibitor) + ketamine treatment group (group AKK).Tracheal rings were suspended in an organ bath filled with oxygenated Kreb's solution at 36.5-37.5 ℃.In group AK,the tracheal rings were precontracted with acetyleholine 0.1 mmol/L,and the rings were then exposed to ketamine 0.4 g/L for 15 min.In group AKI,before acetyleholine and ketamine were added to the solution,the rings were pretreated with IBTX 3μmol/L for 30 min.In group AKK,before acetyleholine and ketamine were added to the solution,the rings were pretreated with KT-5823 2μmol/L for 30 min.The tension of rings was measured by using a force-displacement transducer.Results The amplitude of relaxation of isolated tracheal smooth muscle was significantly decreased in groups AKI and AKK as compared with group AK (P ＜ 0.05).Conclusion Ketamine induces isolated tracheal smooth muscle relaxation through activating BKCa channels and PKG signaling pathway in rats with asthma.

Objective To evaluate the effectiveness and safety of needle-knife fistulotomy (NKF)for difficult cannulation during endoscopic retrograde cholangiopancreatography (ERCP). Methods Data of patients, who received NKF on the back of major papilla when bile duct could not be accessed by conventional cannulation and/or other pre-cut methods during ERCP, were retrospectively reviewed. The success rate of deep cannulation and its complications were observed and analyzed. Results NKF was performed in 108patients due to difficult cannulation, which succeeded in 97 (91.2%) in access to the bile duct and failed in 11 patients with malignant biliary strictures. The failure rate in patients with distal malignant obstruction was higher (25. 8%, 8/31) than those with proximal lesions (5.3%, 3/57) (P = 0. 014, χ2 = 5. 983).Post-ERCP pancreatitis occurred in 5 cases (4. 6%), with the incidence significantly higher in NKF-failure group (18. 2%, 2/11) than that in NKF-suocess group (3.1% ,3/97) (P = 0. 006, χ2 = 7.418). Intestinal perforation occurred in 1 patient and cholangitis developed in 4 others, which all recovered after conservative managements. Conclusion NKF for difficult cannulations in ERCP is safe and effective, especially in hands of experienced operators, but cannulation success rate is relatively low in distal malignant biliary obstruction.