The Regulation Effects of β2-AR on INCX in Myocytes from Infarcted Rat Heart

Objectives This study is designed to investigate the regulation effects of β2-adrenergic receptors （AR） on expression of the Na^± - Ca^2 ± exchanger （ INCX） in myocytes from the infarcted rat heart. Methods Twenty-eight adult Wistar rats were randomly divided into four groups ： the control group, the two weeks, four weeks and eight weeks post-myocardial infarction （post-MI） groups, respectively. The chest of rat was opened and a ligature was placed around the left anterior descending coronary artery. Rats in control group were sham-operated without the coronary artery ligation. After the operation, rats were fed for two, four or eight weeks respectively. Myocytes were enzymatically disassociated by Langendorff perfusion. The whole cell-patch clamp recording technique was used to record INCX in specific pipette solution and superfusion according to the specific holding potential and command potential program. Results The INCX in ventricular myocytes from the border zone of infarcted myocardium increased significantly at eight weeks after MI （0. 51 ± 0. 12 pA/pF vs 1.07± 0. 21 pA/pF, P 〈0.05）. β2-AR agonist increased INcx more strongly in myocytes from post- MI heart than in controls. β2-AR antagonist attenuated the rise of INCX, strongly in myocytes from post-MI heart than in controls, whereas β1-AR onist. Conclusion The regulation effects of β2-AR on INCX in myocytes AR had closer relationship with the genesis of malignant arrhythmia afte     

EflFect of hepatocyte growth factor on left ventricular remodeling after acute myocardial infarction in canine

Background and objectives To investigate the effect of hepatocyte growth factor (HGF) on left ventricular (LV) remodeling after acute myocardial infarction (AMI). Methods AMI was produced by ligation of proximal left anterior descending coronary artery (LAD) in 12 mongrel canines. These animals were randomized into 2 groups. In HGF group (n=6), canines were injected with pc-DNA3-HGF 1 ml (about 300ug) at the margin of infarcted myocardium; in control group (n=6) canines were injected with equal volume of normal saline. Cardiac function and left ventricular remodeling were evaluated with echocardiography at 1,4, 8 weeks after MI. LV myocardium specimens were obtained at 8 weeks and stained with hematoxylin and eosin for histological examination or with sirius red to assess the collagen content. Results Compared with control group, LVEF in HGF group was significantly higher at 4 weeks (49.61 6.66 vs 39.84 6.39; P<0.05) and at 8 weeks (51.57 8.53 vs 40.61 7.67; P<0.05) after AMI, while LVESV was significantly lower in HGF group than that in control group at 8 weeks after AMI (18.98 3.47 vs 25.66 5.86; P<0.05). Posterior left ventricular wall thickness decreased significantly from 1 wk to 8 wks after AMI in control group, while remained unchanged in HGF group.Compared with control group, histological examination showed more neovascularization and less scar, and sirius red staining indicated higher volume of typeⅢcollagen (7.10±4.06% vs 3.77±1.09%; P<0.05) and lower collagenⅠ/Ⅲratio value (1.11±0.52 vs 2.94±2.48; P<0.05) in HGF group. Conclusion HGF gene transfer might improve cardiac function and LV remodeling after acute myocardial infarction by stimulating angiogenesis, reducing fibrosis, and reducing myocardial scarring.     

Effects of Bradykinin B2 Receptor Blockade on Infarct Size and Hemodynamics after Myocardial Infarction in Enalapril-treated Rats

Objectives To study the effects of bradykinin （BK） B2 receptor blockade on infarct size and hemodynamics after myocardial infarction （MI） in rats with angiotensin-converting enzyme （ACE） inhibition therapy. Methods MI was produced by ligating the left coronary artery. The effects of enalapril （ 500 μg/kg·day）, enalapril （ 500 μg/kg · day） with BK B2 receptor antagonist Hoe-140 （500 μg/kg · day）, angiotensin Ⅱ （Ang Ⅱ） type 1 （AT1） receptor antagonist losartan （3 mg/kg · day） on infarct size, left ventricular systolic pressure （ LVSP）, cardiac output index （CI） and stroke volume index （SVI） were observed in rats after MI. Treatments were started on the 2nd day after MI and continued for another 6 weeks. Results Enalapril reduced infarct size and improved CI and SVI compared with the untreated MI group （ P 〈 0. 05 ）, and these effects of enalapril were significantly blunted by concomitant treatment with Hoe-140 （P 〈 0. 05）. Losartan was less effective than enalapril. LVSP were unchanged in the three treatment groups. Conclusions BK can reduce infract size and improve hemodynamics in rats following MI. The cardioprotective effects of ACEI partly result from the action of BK exerted through the B2 receptor.     

Stereoselective propranolol metabolism in two drug induced rat hepatic microsomes

AIM To study the influence of inducers BNF and PB on the stereoselective metabolism of propranolol in rat hepatic microsomes.METHODS Phase Ⅰ metabolism of propranolol was studied by using the microsomes induced by BNF and PB and the non-induced microsome as the control. The enzymatic kinetic parameters of propranolol enantiomers were calculated by regression analysis of Lineweaver-Burk plots.Propranolol concentrations were assayed by HPLC.RESULTS A RP-HPLC method was developed to determine propranolol concentration in rat hepatic microsomes. The linearity equations for R( + )-propranolol and S ( - )-propranolol were A=705.7C+ 311.2C (R =0.9987) and A=697.2C +311.4C (R = 0.9970) respectively. Recoveries of each enantiomer were 98.9%, 99.5%, 101.0% at 60 μmol/L, 120 μmol/L, 240 μmol/L respectively. At the concentration level of 120 μmol/L, propranolol enantiomers were metabolized at different rates in different microsomes. The concentration ratio R (+)/S (-) of control and PB induced microsomes increased with time, whereas that of microsome induced by BNF decreased. The assayed enzyme parameters were: 1. Km. Control group: R( + )30±8, S( - )18 ± 5; BNF group: R( + )34 ± 3, S (-)39 ±7; PB group: R(+)38 ±17, S(-)36± 10.2. Vmax. Control group: R(+ )1.5 ±0.2, S( - )2.9±0.3; BNF group: R(+)3.8±0.3, S(-)3.3±0.5; PB group: R( + )0.07±0.03, S( - )1.94±0.07.3.Clint. Control group: R( + )60±3, S(- )170±30; BNF group: R( + )111.0 ±1, S(- ) 84 ±5; PB group: R(+)2.0 ± 2, S(- )56.0 ± 1. The enzyme parameters compared with unpaired t tests showed that no stereoselectivity was observed in enzymatic affinity of three microsomes to enantiomers and their catalytic abilities were quite different and had stereoselectivities. Compared with the control,microsome induced by BNF enhanced enzyme activity to propranolol R ( + )-enantiomer, and microsome induced by PB showed less enzyme activity to propranolol S(- )-enantiomer which remains the same stereoselectivities as that of the control.CONCLUSION Enzyme activity centers of the microsome were changed in composition and regioselectivity after the induction of BNF and PB, and the stereoselectivities of propranolol cytochrome P450 metabolism in rat hepatic microsomes were likely due to the stereoselectivities of the catalyzing function in enzyme. CYP1A subfamily induced by BNF exhibited pronounced contribution to propranolol metabolism with stereoselectivity to R ( + )-enantiomer. CYP2B subfamily induced by PB exhibited moderate contribution to propranolol metabolism, but still had the stereoselectivity of S( - )-enantiomer.     

Effect of Chaiqinchengqi decoction on sarco/endoplasmic reticulum Ca~（2＋）-ATPase mRNA expression of pancreatic tissues in acute pancreatitis rats

AIM： To investigate the effect of Chaiqinchengqi decoction （CQCQD） on sarco/endoplasmic reticulum Ca2＋-ATPase （SERCA） mRNA expression of pancreatic tissues in acute pancreatitis （AP） rats. METHODS： Thirty Sprague-Dawley （SD） rats were randomized into control group, AP group and CQCQD group （n = 3 × 10）. The rats in the CQCQD group were intragastrically administered with CQCQD （10 mL/kg every 2 h） after induction of AP by intraperitoneal injection of caerulein （50 μg/kg.h × 5） within 4 h. At 6 h after the induction of AP model, pancreatic tissues were collected for the pathological observation, mRNA extraction for determination of SERCA1 and SERCA2 mRNA expression or pancreatic acinar cell isolation for measurement of fluorescence intensity （FI） of intracellular calcium ion concentration [Ca2＋ i. RESULTS： There was no expression of pancreatic SERCA1 mRNA in the control group and the AP group. The expression of pancreatic SERCA2 mRNA in the AP group was down-regulated （expression ratio = 0.536; P = 0.001） compared with the control group, while that in the CQCQD group was up-regulated （expression ratio= 2.00; P = 0.012） compared with AP group. The FI of intracellular [Ca2＋ of pancreatic acinar cells in the AP group （138.2 ± 23.1） was higher than the C group （111.0 ± 18.4） and the CQCQD group （118.7 ± 15.2 ） （P 〈 0.05） and the pancreatic pathological score in the CQCQD group was lower than that in the AP group （5.7 ± 1.9 vs 9.2 ± 2.7, P 〈 0.05）.CONCLUSION： CQCQD can up-regulate the expression of SERCA2 mRNA of pancreatic tissues, reduce intracellular calcium overload and relieve pancreatic tissue lesions.     

Hyperpolarization activated cation current (If) in cardiac myocytes from pulmonary vein sleeves in the canine with atrial fibrillation

Objective To investigate the characteristics of ectopic automaticity and cation current (If) of cardiac myocytes from pulmonary vein sleeves (PVs) in canines with atrial fibrillation. Methods The canines (8–10 years old) were subjected to long-term, rapid atrial pacing (RAP) for 10 weeks, which induced the atrial fibrillation model. Disassociation of PVs of canines yielded single cardiac myocytes from a Landengorff column. Action potential, If and hyperpolarisation activated cyclic nucleotide-gated (HCN) currents were measured with the patch-clamp technique. Results Compared with the control group, cardiac myocytes from the RAP canine PVs had spontaneous diastolic depolarization, shorter action potential duration, and larger If densities. In the group of RAP cells, the half maximal activation potential (V1/2) was found to be less negative (?105.5 ± 5.2 mV) compared to control cells (?87.3 ± 4.9 mV). Current densities of If were increased significantly by β-adrenergic receptor stimulation with isoproterenol and caused an acceleration of current activation. In contrast, If currents in the RAP were reduced by carvedilol, a selective beta-adrenergic receptor. Another important finding is that HCN4-based channels may make a significant contribution to If in PVs cells, but not HCN2. Meanwhile, HCN4 current significantly increases in canine PVs cardiac myocytes with RAP. Conclusions The spontaneous action potential and larger If current were observed in the PVs cardiac myocytes using RAP, which may contribute to more ectopic activity events to trigger and maintain atrial fibrillation.     

Effects of propranolol or propranolol plus isosorbide-5-mononitrate on variceal pressure in schistosomiasis

AIM: To compare the effects of propranolol (PR) to that of PR plus isosorbide-5-mononitrate (ISMN) on variceal pressure in patients with schistosomiasis. METHODS: Forty-eight patients with schistosomiasis who had no previous variceal bleeding were treated with PR alone or PR plus ISMN. Seven patients refused variceal pressure manometry (3 receiving PR and 4 receiving PR plus ISMN). One patient withdrew from the trial due to headache after taking ISMN. At the time of termination, twenty patients were randomly assigned to treatment with PR plus ISMN or PR alone. The dose of PR was adjusted until the resting heart rate had been reduced by 25% or was less than 55 bpm. In the PR plus ISMN group, after PR was titrated to the same target, the dose of ISMN was increased up to 20 mg orally twice a day. Variceal pressure was measured using a noninvasive endoscopic balloon technique at the end of the 6-mo treatment period. RESULTS: In 40 patients (20 in the PR group and 20 in the PR plus ISMN group), variceal pressure was measured before treatment and at the end of the 6-mo treatment period. PR or PR plus ISMN treatment caused a significant reduction in variceal pressure (PR group: from 24.15 ± 6.05 mmHg to 22.68 ± 5.70 mmHg, P = 0.001; PR plus ISMN group: from 25.69 ± 5.26 mmHg to 20.48 ± 5.43 mmHg; P < 0.001). The percentage decrease in variceal pressure was significant after PR plus ISMN compared with that after PR alone (15.93% ± 8.37% vs 6.05% ± 3.67%, P = 0.01). One patient in the PR plus ISMN group and two patients in the PR group had variceal bleeding during follow-up. There were no significant differences between the two groups regarding the incidence of variceal bleeding. In the PR plus ISMN group, three patients had headache and hypotension. The headache was mild and transient and promptly disappeared after continuation of the relevant drug in two patients. Only one patient withdrew from the trial due to severe and lasting headache after taking ISMN. No side effects occurred in the PR group. CONCLUSION:     

Tumor vaccine against recurrence of hepatocellular carcinoma

AIM: To investigate the effects of autologous tumor vaccine on recurrence of hepatocellular carcinoma (HCC). METHODS: Sixty patients with HCC who had undergone curative resection, were randomly divided into HCC vaccine group and control group. Three vaccinations at 2-wk intervals were performed after curative hepatic resection. Delayed-type- hypersensitivity (DTH) test was performed before and after vaccination. Primary endpoints were the time of recurrence. RESULTS: Four patients in control group and 6 patients in HCC vaccine group were withdrawn from the study. The vaccine containing human autologous HCC fragments showed no essential adverse effect in a phase II clinical trial and 17 of 24 patients developed a DTH response against the fragments. Three of 17 DTH-positive response patients and 5 of 7 DTH- negative response patients had recurrences after curative resection. After the operation, 1-, 2- and 3-year recurrence rates of HCC vaccine group were 16.7%, 29.2% and 33.3%, respectively. But, 1-, 2- and 3-year recurrence rates of the control group were 30.8%, 53.8% and 61.5%, respectively. The time before the first recurrence in the vaccinated patients was significantly longer than that in the control patients (P<0.05). CONCLUSION: Autologous tumor vaccine is of promise in decreasing recurrence of human HCC.     

Treatment of unstable angina with trimetazidine

Objective To evaluate the clinical therapeutic effects oftrimetazidine on the treatment of unstable angina （UA） as well as its effects on endothelin- 1 level and complications of patients. Methods One hundred and twenty patients with UA were randomized into the trimetazidine group （n =60） and the control group （n =60）, the trimetazidine group was subjected to treatment with 60 mg trimetazidine everyday for six months plus conventional treatment, and the clinical symptoms, changes in electrocardiogram, changes in the number of plasma circulating endothelial cells （CEC） and endothelin- 1 level of the two groups were observed after treatment for four weeks; and the incidence rates of cardiac arrhythmias, cardiac failure, hospitalization due to angina, myocardial infarction and sudden death were also observed after treatment for six months. Results 1） The total effective rate of integrative clinical therapeutic effects in the trimetazidine group and the control group after treatment for four weeks were 86.7% and 68.3%,respectively （P〈0.05）, and the excellence rates were 36.7% and 15% （P〈0.01）respectively; the total effective rates for the therapeutic effects in electrocardiogram were 66.7% and 46.7%,respectively （P〈0.05）, and the excellence rates were 30.0% and 11.7%, respectively （P〈0.01）. 2） The number of plasma CEC and endothelin-1 level of the two groups after treatment for four weeks significantly decreased （P〈0.05）, but the decreases in the trimetazidine group were even significant （P〈0.01 ）. 3） The incidence rates for cardiac arrhythmia in the trimetazidine group and the control group after treatment for six months were 10% and 20% （P〈0.05）, respectively, and the incidence rates for cardiac failure were 8.3% and 18.3%, respectively （P〈0.05）, and the incidence rates for hospitalization due to angina were 10% and 15%, and the incident rates for myocardial infarction were 3.3% and 13.3% respectively （P〈0.05）. Conclusion Trimetazidine can significantly improve the symptoms of UA and myocardial ischemia, reduce the damages to blood vessel endothelium and complications, and improve the prognosis.     

Expression changes of syndecan-1 in myocardial infarction rats

Background The expression of syndecan-1 after myocardial infarction （MI） is not consistent. In this study, we investigated the changes in the cxpression of synolecan-1 and the relationship between soluble syndeean-1 and syndecan-1 expressed in myocytes after MI. Methods Spreague-Dawley rats survived 24 hours after ligating left anterior descending coronary artery were randomly divided into four groups： MI 1 day group, MI 3 days group, MI 7 days group and MI 14 days group. A Sham-operated group was selected as non-infarcted control. There were 6 rats in each group. At the end of observation the expressions of syndecan-1 mRNA （Realtime RT-PCR） and protein （Western blot） in the peri-infarct myocardium and soluble syndecan-1 in serum （ELISA） were detected. Results There were minimal syndecan-1 mRNA, protein and soluble syndecan-1 expressed in sham-operated rats. The expressions of syndecan-1 mRNA, protein and soluble syndecan-1 increased progressively after MI, reaching their maximum on the 3rd day and decreasing again after that. There were statistically significant differences between each groups （P 0.01）. Pearson correlation analysis showed that the concentration of soluble syndecan-1 in serum was positively correlated with syndecan-1 expressed in peri-infarct myocardium （r = 0.952, P 0.01）. Conclusions The expression of syndecan-1 increases and reaches its maximum on the 3rd day after MI . The concentration of soluble syndecan-1 in serum can reflect the level of syndecan-1 expressed in peri-infarct myocardium to some extent.     

β-2 Adrenergic receptor gene polymorphism and response to propranolol in cirrhosis

AIM: To evaluate the association of β-2 adrenergic receptor(β2-AR) gene polymorphism with response of variceal pressure to propranolol in cirrhosis.METHODS: Sixty-four non-related cirrhotic patients participated in this study and accepted variceal pressure measurement before and after propranolol administration. Polymorphism of the β 2-AR gene was determined by directly sequencing of the polymerase chain reaction products from the DNA samples that were prepared from the patients.RESULTS: The prevalence of Gly16-Glu/Gln27 and Arg16-Gln27 homozygotes, and compound heterozygotes was 29.7%, 10.9%, and 59.4%, respectively.Patients with cirrhosis with Gly16-Glu/Gln27 homozygotes had a greater decrease of variceal pressure after propranolol administration than those with Arg16-Gln27 homozygotes or with compound heterozygotes(22.4% ± 2.1%, 13.1% ± 2.7% and 12.5% ± 3.1%,respectively, P 0.01).CONCLUSION: The variceal pressure response to propranolol was associated with polymorphism of β 2-AR gene. Patients with the Gly16-Glu/Gln27 homozygotes probably benefit from propranolol therapy.     

Effect of early propranolol administration on portal hypertensive gastropathy in cirrhotic rats

AIM： To investigate any protective effect of early propranolol administration in the development of portal hypertensive gastropathy in cirrhotic rats. METHODS： For the development of liver cirrhosis and portal hypertensive gastropathy, 60 rats underwent ligation of the left adrenal vein and complete devascularization of the left renal vein, followed by phenobarbital and carbon tetrachloride （CCl4） administration. After two weeks of CCl4 administration, the rats were randomly separated into two groups. In group A, propranolol was continuously administered intragastrically throughout the study, whereas in group B normal saline （placebo） was administered instead. Hemodynamic studies and vascular morphometric analysis of gastric sections were performed after complete induction of cirrhosis. RESULTS： Vascular morphometric studies showed higher numbers of vessels in all mucosal layers in the control group. Statistical analysis revealed a significantly higher total vascular surface in the control group compared to the propranolol group, but with no statistically significant difference between the mean vascular surfaces between the groups. Our study clearly shows that the increased mucosal blood flow is manifested by a marked increase of vessel count. CONCLUSION： Early propranolol＇s administration in portal hypertensive cirrhotic rats seems to prevent intense gastric vascular congestion that characterizes portal hypertensive gastropathy.     

Effect of propofol and ketamine anesthesia on cognitive function and immune function in young rats

Objective:To investigate the effects of propofol and ketamine on the cognitive function and immune function in young rats.Method:A total of 80 young rats were randomly divided into four groups:Control group,ketamine group(experimental group A),propofol group(experimental group B),ketamine and propofol group(experimental group Q.All rats had continuous injection for three times,serum IL-2,IL-4 and II.-10 and whole brain IL-I P level,hippocampal neuronal apoptosis level were measured.The cognitive ability in rats was tested by water maze.Results:Water maze test showed on the 1st d,the maze test latency of the control group,the experimental group B and the experimental group C water were decreased gradually;Compared with the control group after 3 days,the latency of the experimental group A,experimental group B and experimental group C were all decreased,the crossing circle times were also reduced.Hippocampal neuron apoptosis were(2.3±1.7)%,(14.7±6.9)%,(4.2±3.3)%,(10.2±4.8r%in control group,experimental group A,experimental group B and experimental group C,respectively.The neurons apoptosis of experimental group A was significantly increased.The serum IL-4 and 1L-10 of the experimental group A,experimental group B and experimental group C after anesthesia were significantly higher than the control group.The whole brain IL-1β of the experimental group A,experimental group B and experimental group C were significantly lower than the control group.Conclusions:Propofol can reduce anesthesia effect of ketamine on the cognitive function and immune function in the young rats.     

Effect of hepatocyte growth factor on left ventricular remodeling after acute myocardial infarction in canine

Background and objectives To investigate the effect of hepatocyte growth factor (HGF) on left ventricular (LV) remodeling after acute myocardial infarction (AMI). Methods AMI was produced by ligation of proximal left anterior descending coronary artery(LAD) in 12 mongrel canines. These animals were randomized into 2 groups. In HGF group (n=6), canines were injected with pcDNA3-HGF lml (about 300ug) at the margin of infarcted myocardium; in control group (n=6) canines were injected with equal volume of normal saline. Cardiac function and left ventricular remodeling were evaluated with echocardiography at 1, 4, 8 weeks after MI. LV myocardium specimens were obtained at 8 weeks and stained with hematoxylin and eosin for histological examination or with sirius red to assess the collagen content. Results Compared with control group, LVEF in HGF group was significantly higher at 4 weeks (49.61+6.66 vs 39.84+6.39; P＜0.05) and at 8 weeks (51.57+8.53 vs 40.61+7.67; P＜0.05) after AMI, while LVESV was significantly lower in HGF group than that in control group at 8 weeks after AMI (18.98+3.47 vs 25.66+5.86; P＜0.05). Posterior left ventricular wall thickness decreased significantly from 1 wk to 8 wks after AMI in control group, while remained unchanged in HGF group. Compared with control group, histological examination showed more neovascularization and less scar, and sirius red staining indicated higher volume of type Ⅲ collagen (7.10&#177;4.06% vs 3.77&#177;1.09%; P＜0.05) and lower collagen Ⅰ/Ⅲ ratio value (1.11&#177;0.52 vs 2.94&#177;2.48; P＜0.05)in HGF group. Conclusion HGF gene transfer might improve cardiac function and LV remodeling after acute myocardial infarction by stimulating angiogenesis, reducing fibrosis, and reducing myocardial scarring.     

Antihypertensive efficiency and safety of L - & N-type Ca~(2+) antagonists -cilnidipine

Objectives To evaluate antihypertensive efficiency and safety of a new domesticof L - & N - type Ca2+ antagonist - cilnidipine with imidapril as a positive control. Methods After 2 weeks' placebo washingout, 22 patients were treated with cilnidipine 5 mg daily and 27 patients were treated with imidapril 5 mg daily. 4 weeks later, if patient's sitting diastolic blood pressure is over 90 mmHg, his/ her dosage was doubled for another 4 weeks, the others measuring up remained their dosage unchanged for another 4 weeks. Blood pressure, heart rate, blood and urine routine examination, serum glucose, serum chemical examination including total cholesterol, triglyceride. HDL, LDL, transaminase, creatine etc and side reactions were recorded before and after the trial. Data were analyzed statistically. Results After 8 weeks' treatment, blood pressure was significantly decreased ( P < 0. 05) in both groups, and the two medicines had similar antihypertensive effects. Furthermore, the reducing of heart rate was stati     

Inhibitory effect of interferon-α-2b on expression of cyclooxygenase-2 and vascular endothelial growth factor in human hepatocellular carcinoma inoculated in nude mice

AIM： To evaluate the effects of interferon-α-2b （IFN- α-2b） on expression of cyclooxygenase-2 （COX-2） and vascular endothelial growth factor （VEGF） in human hepatocellular carcinoma （HCC） inoculated in nude mice and to study the underlying mechanism of IFN-α- 2b against HCC growth. METHODS： Thirb/-two nude mice bearing human HCC were randomly divided into four groups （n = 8）. On the 10th day after implantation of HCC cells, the mice in test groups （groups A, B and C） received IFN-α- 2b at a serial dose （10000 IU for group A, 20000 IU for group B, 40000 IU for group C sc daily） for 35 d. The mice in control group received normal saline （NS）. The growth conditions of transplanted tumors were observed. Both genes and proteins of COX-2 and VEGF were detected by RT-PCR and Western blot. Apoptosis of tumor cells in nude mice was detected by TUNEL assay after treatment with IFN-α-2b. RESULTS： Tumors were significantly smaller and had a lower weight in the IFN-α-2b treatment groups than those in the control group （P 〈 0.01）, and the tumor growth inhibition rate in groups A, B and C was 27.78%, 65.22% and 49.64%, respectively. The expression levels of both genes and proteins of COX-2 and VEGF were much lower in the IFN-α-2b treatment groups than in the control group （P 〈 0.01）. The apoptosis index （AI） of tumor cells in the IFN-α-2b treatment groups was markedly higher than that in the control group （P 〈 0.01）. Group B had a higher inhibition rate of tumor growth, a lower expression level of COX-2 and VEGF and a higher AI than groups A and C （P 〈 0.05）, but there was no significant difference between groups A and C. CONCLUSION： The inhibitory effects of IFN-α-2b on implanted tumor growth and apoptosis may be associated with the down-regulation of COX-2 and VEGF expression. There is a dose-effect relationship. The medium dose of IFN-α-2b for inhibiting tumor growth is 20 000 IU/d.     

Enhancement of CD^4＋ T cell activities and modulation of Th1/Th2 lineage development in radiated tumor-bearing rats treated with male zooid of Antheraea pernyi extracts

AIM： To investigate whether supplementation of male zooid of Antheraea pernyi extracts （MZAPE） could enhance immune function of radiated tumor-bearing rats. METHODS： Eighty male Wistar rats were randomly divided into a control group, a simple radiation group, a MZAPE group, and a radiation plus MZAPE group. With the tumor model established by implanting Walker-256 ascites tumor cells, tumor weight and tumor control rate were calculated. The rats in the simple radiation and radiation plus MZAPE groups were underwent to radiation at 10 Gy within 2 d. In the MZAPE and radiation plus MZAPE groups, the MZAPE was gavaged at a dose of 16.53 mg/kg once a day for 7 d. T cell subsets in peripheral blood were determined by flow cytometry and the expression of IL-2, IFN-γ, IL-4 and IL-10 in sera were determined by ELISA on the 8th d. RESULTS： The tumor weight of simple radiation group, MZAPE group and radiation plus MZAPE group was lower than that of control group （P 〈 0.01） and tumor control rates were 63.08% ± 6.43%, 69.86%± 7.12% and 35.30% ± 7.67%, respectively. CD^4＋ T and CD^8＋ T cells in the peripheral blood of the simple radiation group were fewer than in control group. In the MZAPE and radiation plus MZAPE groups, the number of CD^4＋ T cells was higher while CD^8＋ T cells was lower than in the control and simple radiation groups. Expression of IL-2 and INF-y in the radiation group was lower than in control group, and significantly enhanced during MZAPE therapy （P 〈 0.05）. Expression of IL-4 and IL-10 in the radiation group had no significant changes compared with the control group, and decreased significantly after MZAPE treatment （P 〈 0.01）. CONCLUSION： MZAPE administration may help improve the immune function of the radiated tumor-bearing rats and reverse the radiation-induced immune inhibition by promoting the proliferation of T helper cells and inducing the transdifferentiation from Th2 to Th1.     

Role of Bradykinin on Left Ventricular Remodeling and Cardiac Function after Myocardial Infarction in Rats

Objectives To investigate the influences of bradykinin （BK） on hemodynamics, left ventricular hypertrophy and interstitial collagen metabolism after myocardial infarction （MI） in rats and the contribution of BK in angiotensin-converting enzyme （ACE） inhibition therapy. Methods By means of hemodynamic measurements, morphometric study of myocyte hypertrophy and SDS-PAGE technique, the effects of enalapril （500 μg.kg^-1.day^-1 ）, enalapril （500 μg.kg^-1.day^-1） with BK B2 receptor antagonist Hoe-140 （500 μg . kg^-1.day^-1）, angiotensin Ⅱ （AgⅡ） type 1 （AT1） receptor antagonist losartan （3 mg.kg^-1.day^-1 ） on mean arterial pressure （MAP）, left ventricular end-diastolic pressure （LVEDP）, as well as maximum positive left ventricular pressure change （ ＋ dp/dtmax）, V（m） n, collagen content and the ratio of type Ⅰ to type Ⅲ collagen （ Ⅰ / Ⅲ ） of noninfarcted area were observed in rats after MI. Treatments were started on the 3rd day after MI and continued for another 28 days. Results Enalapril reduced LV- EDP, V （m） n and collagen content as well as collagen Ⅰ /Ⅲ compared with the untreated MI group （ P 〈 0. 05 ）, and all of these effects of enalapril were partly blunted by concomitant treatment with hoe-140 （ P 〈 0. 05 ）. Losartan was less effective than enalapril （P 〈 0. 05 ）. However, three treatment groups had no significant differences in ＋ dp/dtmax and had similar reductions in MAP compared with untreated MI group. Conclusions BK can improve cardiac function and prevent left ventricular hypertrophy with myocardial fibrosis independent of blood pressure. The mechanisms of ACEI are both blockade of Ang Ⅱ formation and inhibition of BK degradation.     

Experimental Study of Nicotine on Angiogenesis and Restenosis

Objectives To investigate the effects of nicotine on angiogenesis and restenosis in a rabbit model of critical limb ischemia and balloon catheter denuding injury iliac artery. Methods Forty male New Zealand White rabbits were randomly divided into control, low-,middle-, and high-dose (0.005,0.05 or 5μg/kg, respectively) nicotine groups.Balloon catheter denuding injury iliac artery and ligation of a femoral artery were performed in all animals fed with a high-cholesterol diet (HCD)beginning 2 weeks before operation. Nicotine was administered daily by intramuscular injection in the ischemic hindlimb for 3 weeks. Control rabbits received an equal volume of phosphate-buffered saline alone.Collateral vessels of the ischemic hindlimb were observed by angiography of abdominal aorta, and the density of intramuscular microvessels in ischemic hindlimb was examined by immunohistochemistry. The levels of blood lipids and the indexes of hepatic or renal functions were also determined before HCD and after nicotine treatment. Results One rabbit in control, two in low-, one in middle- and two in high-dose group died during the experiment. The remaining 34 rabbits were included in the study. Two or five weeks after HCD, the levels of blood lipids were significantly increased in all groups, but there was no significant difference on the levels between control and nicotine-treated groups three weeks after nicotine treatment; The indexes of hepatic or renal functions were no significant changes three weeks after nicotine treatment; There were no significant differences on collateral vessels shown by angiography in all four groups; The density of intramuscular microvessels in three nicotine-treated groups was significantly higher than that in control group; But the intimal area in all three nicotine-treated groups was also larger than that in control group.Conclusions The present study shows that intramuscular administration of nicotine for three weeks could not increase arteriogenesis in ischemic hindlimb of rabbits, but is capable of significantly promoting intramuscular angiogenesis in ischemic hindlimb.Nicotine can also accelerate intimal thickening of balloon catheter denuding injury lilac artery, so it may contribute to the development of restenosis.     

人组织因子途径抑制物基因在兔颈动脉损伤血栓形成中的作用

Objective To observe the effects of tissue factor pathway inhibitor(TFPI) on thrombosis formation in rabbit carotid arteries after ballon injury. Methods Fouty rabbits with the weight 2.5-3.0 kg were respectively divided into 4 groups, Ad-TFPI, Ad-LacZ, PBS and normal control groups. The normal control group was not given any treatment and other 3 groups were given 0.2 ml Ad-TFPI, Ad-LacZ or PBS reproduced by the Dispatch catheter respectively after the PTCA balloon iniury on the right carotid arteries. Ten days after gene transfer the repeated balloon injury was performed in the 3 groups, and the first balloon injury was performed in the normal control group by the same method. The carotid blood flow was recovered immediately after the injury. Thirty minutes later all the animals were sacrificed. The injured carotid arteries and one part of contralateral normal artery were cut down, scissored along the long axis, flattened and fixed in the 2% glutaral. The platelet aggregation and thrombosis formation on the luminal surfaces was observed under electron microscope. Results The electron microscope results showed that the vascular endothelial cell structure was integrated and lined up in order in the nomal artery which had no any injury. After the balloon injury in the normal control group, the structure of the endothelial cell was disintegrated, and there was some platelet aggregation but no fibrosis formation. A large amount of platelet aggregated but no fibrosis formed in Ad-TFPI group after the repeated balloon injury. A large amount of fibrosis formed and red cells piled up in the Ad-LacZ and PBS group. The positive rate of thrombosis formation among groups had siginificant differences(χ2=14.95, P<0.01). The positive rate in Ad-TFPI group(20%) was lower than that in Ad-LacZ group(80%, χ2=7.20, P<0.01) and PBS group(70%, χ2=5.05, P<0.05), but was higher than that in the normal control group(10%, χ2=0.39, P>0.05). The positive rate in Ad-LacZ group(80%) was higher than in the normal control group(10%, χ2=9.90, P<0.01) and in the PBS group(70%, χ2=0.27, P> 0.05). The positive rate in PBS group(70%) was higher than that in the normal control group(10%, χ2=7.50, P< 0.01). Conclusions The repeated balloon injury method can cause a large amount of fibrosis formation in the rabbit carotid. TFPI gene inhibits thrombosis formation in balloon-injured rabbit carotid arteries.