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OBJECTIVE To establish a platform of electrophysiology using vagal ganglion neurons (VGNs) isolated from adult canines. METHODS The VGNs were enzymatically isolated from adult canines of either gender and cultured under experimental conditions. Action potential (AP), repetitive firing, voltage-gated outward K+ currents (IK) and hyperpolarization-mediated inward currents (Ih) were recorded under current-and voltage-clamp configurations before and after treatment. RESULTS Analysis of AP waveform showed that ① inaddition to traditionally classified myelinated A- and unmyelinated C-types, myelinated Ah-types could also be identified in females rather than in males; ② step current depolarization evoked a stimulus intensity-dependent repetitive discharge, and to reach a similar firing frequency, the lowest stimulus intensity was required for A-types, a similar or slightly higher stimulus intensity was needed for Ah-types, and the highest stimulus intensity was required for C-types;③tetro?dotoxin significantly reduced the rate of depolarization and positively shifted the AP firing threshold of Ah-types, and iberiotoxin dramatically increased the neuroexcitability of Ah-types;④all tested neurons functionally expressed IK and Ih, and the current density for both channels on average was A-types>Ah-types>C-types; ⑤ although the distribution of afferent types of VGNs differed between males and females, the known difference in discharge profiles of A- and C-types isolated from male and female rats was not studied here. CONCLUSION The VGNs can be successfully isolated from adult canines, AP, IK and Ih can be recorded. The tight seal can be held for at least 30 min, which may be enough for pharmacological investigation.
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Fenofibrate, an agonist for peroxisome proliferator-activated receptor alpha (PPAR-α), lowers blood pressure, but whether this action is mediated via baroreflex afferents has not been elucidated. In this study, the distribution of PPAR-α and PPAR-γ was assessed in the nodose ganglion (NG) and the nucleus of the solitary tract (NTS). Hypertension induced by drinking high fructose (HFD) was reduced, along with complete restoration of impaired baroreceptor sensitivity, by chronic treatment with fenofibrate. The molecular data also showed that both PPAR-α and PPAR-γ were dramatically up-regulated in the NG and NTS of the HFD group. Expression of the downstream signaling molecule of PPAR-α, the mitochondrial uncoupling protein 2 (UCP2), was up-regulated in the baroreflex afferent pathway under similar experimental conditions, along with amelioration of reduced superoxide dismutase activity and increased superoxide in HFD rats. These results suggest that chronic treatment with fenofibrate plays a crucial role in the neural control of blood pressure by improving baroreflex afferent function due at least partially to PPAR-mediated up-regulation of UCP2 expression and reduction of oxidative stress.
Assuntos
Animais , Masculino , Vias Aferentes , Anti-Hipertensivos , Farmacologia , Barorreflexo , Pressão Sanguínea , Fenofibrato , Farmacologia , Estresse Oxidativo , PPAR gama , Metabolismo , Ratos Sprague-Dawley , Transdução de Sinais , Ativação Transcricional , Proteína Desacopladora 2 , Metabolismo , Regulação para CimaRESUMO
Objective To investigated the effects of combined arsenic trioxide(ATO) and resveratrol(Res)on the viability of NB4 human leukemia cells. Methods NB4 human leukemia cell was used in this experiment.Cells were cultured in ATO (0,0.1875,0.3750,0.7500, 1.1250, 1.5000,2.2500,3.0000,5.0000 μmol/L) and Res (0, 1.5625,3.1250,6.2500, 12.5000, 18.7500,25.0000,37.5000,50.0000 μmol/L). Cell viabilities were measured by MTT in different treatment groups. Half inhibitory concentration(IC50) was calculated. The ratio of concentration of ATO and Res 1.5∶ 18,1.5∶ 25,1.5∶ 35 was added to cells, and the combination index(CI) was calculated. The level of ROS in control, ATO( 1.5000 μmol/L), Res(25.0000 μmol/L) and ATO(0.9000 μmol/L) + Res( 12.5000μmol/L) groups was measured by chemiluminescence assay. Results ①ATO( ≥0.7500 μmol/L) reduced the viability of NB4 cells in a concentration-dependent manner(P ＜ 0.05 ), and IC50 was (1.78 ± 0.11 )μmol/L. ②)Res (≥18.7500 μ mol/L) dose-dependently decreased the viability of NB4 cells (P ＜ 0.05 ), and IC50 was ( 18.71 ±0.18)μ mol/L. ③Combination of ATO and Res showed an antagonistic effect on NB4 cells viability. ④The ROS in Res group( 1670.55 ± 13.97) was significantly lower than that in control group(2345.88 ± 14.48,P ＜ 0.05). The ROS in ATO group (3092.42 ± 94.84) was significantly higher than that in control group(P ＜ 0.05). The ROS in ATO + Res group (1860.27 ± 15.99) was significantly lower than that in ATO group(P ＜ 0.05). Conclusions NB4 cell survival rate can be decreased by ATO and Res. The combination of arsenic trioxide and Res presents an antagonistic effect on NB4 cell viability, in part by reducing intracellular ROS formation.
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Objective To study the effect of Asi-antidiarrheal capsule on gastrointestinal goblet cell of thyroid hormone-induced diarrhea.Methods Total of 120 SD male rats aged about 8 weeks were randomly divided into 2 groups:control group(10 rats)and thyroid hormone-induced diarrheic group(110 rats).Rats in control group were lavaged with normal saline 1 ml/d.Thyroid tablets were partly desolved into normal saline forming a 40 mg/ml suspension.Rats in thyroid hormone-induced diarrheic group were given the thyroid suspension 1 ml/d to make thyroid hormone-induced diarrheic model.Serum FT3 and FT4 were tested.Fourty thyroid hormone-induced diarrheic rats were screened out according to serum FT3 and FT4 levels,body weight and wet stool.The fourty rats were randomly divided into 5 groups,8 rats in each group:positive control group,berberine group,low-dose,mediandose and high-dose groups.Normal saline of 1 ml/d was admnistered to diarrhea control group,1.94 g·kg-1·d-1 Berberine capsule was given to positive control group,and 0.63,1.26,2.52 g·kg-1·d-1 Asi-antidiarrheal capsule to low-dose,mediandose and high-dose groups,respectively.After sever days treatment,rats are executed.Duodenum,jejunum,ileum and colon were dissected,respectively.Histology observation and cell counting were carried out under light micmscopo on HE coloration.Cell counting unit was defined as:cell/high power field of vision (cells/hpf).Results In jejunum,the number of goblet cells in berberine group,mediandose group and high-dose group[(15.32±2.53),(20.24±1.24),(14.98±1.10)cells/hpf,respectively],were all lower than that of the diarrhea control group[(25.73±4.55)cells/hpf,all P<0.05]with an exception of low-dose group[(23.98±2.28)cells/hpf].The numbers of goblet cells in berberine control group,low-dose group,mediandose group and highdose group[(18.29±1.33),(20.61±2.12),(19.38±2.01),(16.34±1.55)cells/hpf,respectively]were all less than that of the control group[(23.36±3.10)cells/hpf,all P<0.05].The numbers of goblet cells of diarrhea control group and high-dose group were obviously lower than that of the low-dose group(all P<0.05)in jejunum and colon.The numbers of goblet cells of Duodenum and ileum were not significantly different between groups(F=2.81,2.67,all P>0.05).The numbers of goblet cells in the diarrhea control group increased markedly observed under microscope,but decreased following therapeutic treatment.Conclusions The numbers of goblet cells from jejunum and colon in thyroid hormone-induced diarrheic rats are increased significantly.Asi-antidiarrheal capsule can remarkably decrease the number of goblet cells in jejunum and colon,and reduce mucus secretion.
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Objective Investigate the Asi-antidiarrheal capsule's effect on gastrointestinal horrnones in blood plasma of thyroid hormone-induced diarrheic(Abbreviation:Hyperthyroid Diarrhea.,D)rats.Methods One hundred and twenty SD male rats about 8 weeks old were randomly divided according to their constitution into control group of 10 rats and thyroid hormone-induced diarrheic group of 110 rats.The control group rats welle hvaged with isotonic Na chloride 1 ml/d.Thyroid tablets were made with isotonic Na chloride into 40 g/L susnl. The such solution with 1 ml/d was intragastrically administered to each rat in thyroid hormone-induced diardleic group.After three weeks,blood was sampled from vena caudalis of each rat.FT4 were then detected in blood semm.Fourty-two thyroid hormone-induced diarrheic rats were screened based on FT3 and FT4 level in blood serum, wet stool and body weisht.Fourty thyroid hormone-induced diarrheic rats were stochastically re-divided into 5 groups with 8 in each.The physiological saline with 1 ml/d was given to blank group,1.94 g·-kg-1·d-1 Berberine capsule to positive control group,and 0.63,1.26,2.52 g·kg-1·d-1 to low-dose,moderate-dose and high-dose groups respectivelv. Intragastric administration of each group continued for 7 days.Venous blood was centrifuged before and after administration and underwent radioimmunoassay to observe the effect of Ashi-antidiarrheal capsule on motillty (MTL),gastrin(GAS),somatostatin(SS),vasoactive intestinal polypeptide(VlP)in blood plasma of thyroid homlone- induced diarrheic rats.Results①Weight of thyroid hormone-induced diarrheic rats decreased[(344.0±12.9)g], FT3[(4,58 ±0.70)mol/L]and FT4[(23.44±4.40)mol/L]increased,and weight of wet stool[(17.4±3.2)g] increased.Compared to control group[(386.0±1.8)g,(2.08±0.10)mol/L,(10.18±2.00)mol/L,(9.1±0.6)g], there was a statistical significance(t=6.85,9.80,7.66,7.18,P<0.01).②After treatment,high-dose Ashi-antidiarrheal group[(80.54 ±3.80)ng/L]and positive control group[(90.63 ±9.99)ng/L]blood plasma MTL, compared to pre-therapy[(204.27±17.69),(187.79±13.32)ng/L]was decreased,there wag a statistical significance (t=8.60,4.57,P<0.01)③GAS contentshad respectively decreased comparedtopre-therapy[(192.75±11.80), (193.09±3.81),(190.60±9.31),(196.33±18.13)ng/L]in positive control group[(56.06 ±6.36)ng/L],low- dose group[(90.88±4.18)ng/L],midst-dose group[(75.64±7.09)ng/L]and hish-dose group[(44.32±3.72) ng/L],except for blank group.There Wag a statistical significance(t=15.27,7.62,13.43,13.22,all P<0.01).The intm-group difference of MTL,GAS and VIP level had statistic signifieances before and after the treatment(F= 166.68,1503.53,216.68,P<0.01).Conclusion Ashi-antidiarrheal capsule Can significantly lower the level of MTL and GAS in blood plasma。And raise the level of VIP.