Objective To study the effects of acute weak vagus nerve stimulation on hippocampal CA1 unit discharges and field potentials of normal and epileptiform discharging rats.Methods The experiments were performed with 55 male Sprague-Dawley rats weighing 180～250 g,SPF grade.Animals were divided into normal(n=45)and regularly epileptiform discharging(n=10)groups.The normal rat group:Separate the left neck vagus nerve and ligate the peripheral end.Acute weak electrical stimulation(10 Hz,0.5 ms,1.5～5.0 V,15～20 unit /train)were administered to the left neck vagus nerve central end.20 trains were performed with a regular interval of 5 min.Record the unit discharges of right hippocampal CA1 and field potentials of bilateral hippocampal CA1.The epileptiform discharging group:Gelatin spongia was put onto the left cortex to induce epileptiform discharges.After 30 min stable regularly discharging,continue the procedure in the first group.Results Cyclical theta oscillation(about 3～6.5 Hz)appeared in bilateral hippocampal CA1 of normal rats after the stimulation(strain m=5～7,38/45,84.4%).With oscillation,there is unit discharging.It has two kinds:theta-on(n=30)and theta-off(n=5).The sharp wave amplitude was inhibited while the sharp wave interval increased following the acute weak vagus nerve stimulation(n=10)in epileptiform discharging rats.Theta oscillation was induced during the sharp wave.With oscillation,there is tonic unit discharging(n=10).The number of action potential spikes positively correlate with the sharp wave intervals(P

Objective To explore the mechanism of adenosine triphosphatase (ATPase) of calcium overload in vascular smooth muscle cell (VSMC) in hemorrhagic shock rats. Methods Twenty-four male Wistar rats were randomly divide into four groups: control (Group C), shock start (Group S0), 2 hours post-shock (Group S2) and 4 hours post-shock (Group S4). The rat models with hemorrhage shock were produced by means of modified Wigger's method through bloodletting from femoral artery and keeping blood pressure at 40 mm Hg for 2 hours. The changes of cytosolic free Ca 2+ concentration (i) and the activities of Ca 2+ - ATPase and Na +-K +- ATPase in VSMC membrane and mitochondrial membrane were monitored in rats after shock. Results Mean channel fluorescence values of VSMC i in the Groups C, SO, S2 and S4 were 2.03?0.15, 2.37? 0.32 , 2.55?0.46 and 2.80?0.43 respectively and increased in a time-dependent fashion. Mean channel fluorescence values of VSMC i in the Groups S0, S2 and S4 was significantly higher than that in the Group C ( P

To investigate the alterations of contractile function of VSM and it's primary mechanism in hemorrhagic shock rats, contractile tension of vascular rings induced seperately by NE,PE,Caffeine and K + was measured with tension conductor and physiological recorder. The results showed that after 2h and 4h of shock, contractile tension of vascular rings to NE was 76 17% and 66 50% as compared to the control group; contractile tension to 20 mmol/L caffeine and over 20 mmol/L K + was significantly decreased after 2h of shock;and decreased to 3?10 -6 M PE after 4h of shock. The data suggested that contractile tension of VSM would decrease after shock and it maybe at least in part related to the decreased function of both calcium influx from ex cells and calcium release from sarcoplasmic reticulum of vascular smooth muscle cells.

Objective To investigate the effects of Oxytocin(OT) on hippocampal long-term potentiation(LTP) and FOS protein expression induced by peripheral stimulation.Methods Single stimulation pulses were delivered to the left sciatic nerves to evoke the field excitatory postsynaptic potentials (fEPSPs) in the right hippocampal CA1. Tetanic stimulation was used to induce hippocampal LTP. Different groups of rat were given NS,OT,Oxytocin antagonist-Atosiban + OT before tetanic stimulation,into lateral ventricle(LV) respectively. Expression of FOS protein was compared among the groups by histopathological and immunohistochemistry. Results Single stimulation evoked fEPSPs in hippocampal CA1,which average latency was (171.9?33.1)ms and average amplitude was (25.7?8.4)?V. Tetanic stimulation induced hippocampal LTP and increased the expression of FOS protein. Intracerebroventricular injection of OT inhibited hippocampal LTP and decreased the expression of FOS protein. This effect of OT was blocked by the pretreatment with Atosiban. Conclusion The results suggested that OT may play an inhibitory role in leaning and memory of rats and the effect is mediated by OT receptor.

BACKGROUND: Central oxytocin (OT) may be a neurotransmitter or neuromodulator and play an important role in learning and memory, sexual behaviour, pain modulation and opiate tolerance and dependence. To research the interactions between oxytocinergic and opioidergic system in hippocampus has some significance.OBJECTIVE: To investigate the effects of OT administered intracerebroventricularly on evoked discharge of left dorsal hippocampal CA1 neurons in rats and the possible interactions between oxytocinergic and opioidergic system.DESIGN: A randomised controlled study.SETTING: Department of Physiology of Guangdong Medical College; Department of Physiology and Pathology of Medical College of Wuhan University.MATERIALS: The study was conducted in the Physiology Department of Medical College of Wuhan University from September 2002 to September 2003. A total of 36 male Sprague-Dawley rats were selected and randomly divided into six groups: control (NS), OT groups (0.2 mg/L, 2 mg/L and 20 mg/L), [d (CH2)5-OVT]+OT (2 mg/L), naloxone+OT (2 mg/L), with 6 rats in each group.METHODS: Single-unit recording was performed with glass microelectrode. The glass microelectrode was inserted by a micromanipulator into hippocampal CA1. The electrical activity was amplified by a microelectrode amplifier and then recorded by the biological experimental system,monitored at the same time with oscilloscope. When recording the neural discharge, electrical stimulation of the sciatic nerves was performed once 5minutes through a double stainless electrode. 5 μL oxytocin in dosage of 0.2, 2 and 20 mg/L were injected slowly into lateral ventricle via microlitre syringe. [d(CH2)5-OVT]+OT (2 mg/L) group: 2.5 μL [d(CH2)5-OVT](80 mg/L) was injected into lateral ventricle and then 2.5 μL oxytocin (2 mg/L). Naloxone+OT (2 mg/L) group: 2.5 μL naloxone (400 mg/L) was injected into lateral ventricle and then 2.5 μL oxytocin (2 mg/L). According to frequency of discharge, effect of oxytocin at various dosages on discharge induced by neurons in hippocampal CA1 area and [d (CH2)5-OVT]and naloxone on oxytocin was assayed. MAIN OUTCOME MEASURE: Changes of discharge frequency after stimulation.RESULTS: Data of totally 36 rats were entered the final analysis. ① OT (0.2 mg/L, 2 mg/L and 20 mg/L) administered by intracerebroventricularly could decrease the evoked discharge of hippocampal CA1 neurons in a dose-dependent manner. ② The inhibitory effects of OT (2 mg/L) could be blocked by pretreated intracerebroventricularly injection of [d (CH2)5-OVT](80 mg/L, 2.5 μL). ③ Intracerebroventricular injection of naloxone (400 mg/L, 2.5 μL) could attenuate the effects of OT (2 mg/L) significantly.CONCLUSION: OT can inhibit the electrical activities of hippocampal CA1 neurons to external electrical signal through activating the oxytocin receptor. Moreover, central opioid receptor is involving in the inhibitory effects of OT.

Objective To evaluate the effect of morphine on synaptic long-term potentiation (LTP) in the spinal dorsal horn evoked by electric stimulation of sciatic nerve in rats. Methods Twenty-seven healthy male SD rats aged 60-90 d weighing 180-200 g were randomly divided into 4 groups: group Ⅰ control (group C, n=7), group Ⅱ morphine (group M, n=7), group Ⅲ naloxone (group N, n=6), and group Ⅳ morphine + naloxone (group MN, n=7). The animals were anesthetized with intraperitoneal 10% urethane 1 g/kg, intubated and then mechanically ventilated. The bipolar insulated stainless steel recording electrode (impedance 0.5-1 MΩ, diameter 0.1 mm) was inserted into the left side of the spinal dorsal horn at T13-L1 to stimulate the left side of the sciatic nerve. Single square pulses (15 V, 0.5 ms, 1/60 Hz for 30 min) was applied to evoke spinal field potentials. Normal saline 10 μl, morphine 10 μl (15 μg/μl), naloxone 10 μl (2.5 μg/μl), and the mixture 10 μl of naloxone 5 μl (2.5 μg/μl) and morphine 5 μl (15 μg/μl) was gradually instilled over 2 rain in the 4 groups respectively. Five minutes later, high-frequency and intensity tetanic stimulation (30-40 V, 0.5 ms, 100 Hz, given in 4 trains of 1-s duration at 10-s intervals) was used to induce LTP. Then single square stimuli (15 V, 5 ms, 1/60 Hz) were applied to the sciatic nerve for 210 min. The amplitude and latency period of the field potential were recorded 30 min before tetanic stimulation, and 0-30, 35-60, 65-120 and 125-210 min after titanic stimulation. Results Compared with group C, the amplitude of the field potential was significantly decreased and the latency period prolonged in group M and MN, but there was no significant difference in the above indices between group N and C. Compared with group M, the amplitude of the field potential was significantly increased and the latency period shortened in group MN. Compared with those 30 min before the tetanic stimulation, the amplitude of the field potential was significantly increased and latency period shorted at the time points after the tetanie stimulation in group C and N, the amplitude of the field potential was significantly decreased and latency period prolonged at the time points after the tetanie stimulation in group M, and the amplitude of the field potential was significantly increased 0-30 and 35-60 min after the tetanic stimulation and latency period shortened 0-30 min after the tetanie stimulation, the amplitude of the field potential was significantly decreased and latency period prolonged 65-120 and 125-210 min after the tetanic stimulation in group MN. Conclusion Morphine can inhibit synaptic LTP in the spinal dorsal horn evoked by electric stimulation of sciatic nerve in rats, and it may be one of the mechanisms of the central sensitization inhibition.

This paper reports the results of forensic pathological study of 128 autopsycases of sudden coronary death(SCD).The severity of the coronary arterystenosis was 4 degree in 63 cases,3 degree in 26 cases and 2 degree in 39 cases.The distribution of the artheroscleorosis of 3 and 4 degree was quite extensive. Recent thrombosis in CA was found in 18 cases,hemorrhage in plaques in 17cases.Only 2 cases had acute myocardial infarction.Inflammatory cell infil-tration were found in coronary plaques in 36 cases.Myocardail fibrosis orsmall scar formation were detected in 56 cases.It is suggested that SCD isthe commonest cause of sudden unexpected death.The majority of SCD(61%)were manhood in middle age.Most cases died suddenly during sleep withoutany clear inducements.The characteristics of the pathological changes in theCA and myoc ardium and the pathological diagnosis of SCD were analyzedand discussed.

Myoglobin (Mb)depletion from myocardium in the cases of sudden soronary death (SCD) and was firstly studied by an immunhistochemial technique (ABC method) in China. Mb was detected quantitatively using scanning microscope photmeter and the results were analyzed statistically by computer The results showed that there were marked depletion of Mb from myocardium in each case of SCD The Mb depleted arce were multiple, disseminatly and segmentally distributed while no depletion of Mb from myocardium in the cases of control group was seen We suggested that the depletion of Mb can be used as one of the diagnostic criterion in the cases of SCD.

Objective To analyze the medical service capacity of primary healthcare in Zhejiang province since the ongoing healthcare reform and put forward suggestions. Methods Key indicators of healthcare resources and medical service utilization from 2009 to 2015 reflecting the primary healthcare were identified,for a quantitative analysis in terms of the structure-process-outcome dimensions. Results In terms of structural service capacity,the average headcount growth rate of primary healthcare′s technical personnel was 5. 7% per year; the personnel competence structure kept improving; the hospital beds at primary institutions and their ratio among all were slightly decreased,with better devices and informatization. In terms of procedural service capacity,the proportion of primary institutions with contract-based services amounted to 89. 9%,with the standard contract signing rate up to 18. 8%. In terms of consequential service capacity,the average growth rate of the number of outpatient visits at primary institutions was 6. 3%. The amount and proportion of inpatients were slightly decreased,while the hospital bed utilization ratio was increased slightly. Conclusions It is necessary to further strengthen the training and introduction of primary healthcare professionals. The functional orientation of hospitals at various levels should be clarified, encouraging contract-signing of general practitioners, promote the medical insurance payment reform featuring the capitation payment at primary level,and improve the income distribution and incentive mechanism.

Alcohols ; Animals ; Carbon Tetrachloride ; Collagen Type I ; metabolism ; Collagen Type III ; metabolism ; Disease Models, Animal ; Drug Therapy, Combination ; Glycyrrhetinic Acid ; therapeutic use ; Hepatocytes ; drug effects ; Interferon-alpha ; therapeutic use ; Liver Cirrhosis ; chemically induced ; drug therapy ; metabolism ; Male ; Rats ; Rats, Sprague-Dawley