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1.
Zhonghua Yan Ke Za Zhi ; 58(3): 205-212, 2022 Mar 11.
Artigo em Chinês | MEDLINE | ID: mdl-35280029

RESUMO

Objective: To screen the differently expressed microRNAs (miRNAs) and to explore the effect and mechanism of microRNA-3907 (miR-3907) in meibomian gland carcinoma (MGC). Methods: Experimental research. MGC tissues and para-carcinoma tissues of patients diagnosed with MGC by histopathology were collected from July 2011 to January 2019 in Tianjin Medical University Eye Hospital. The miRNA microarray analysis of MGC and para-carcinoma tissue samples from 5 patients was performed. miR-3907 with a significant up-regulation was selected as a research object. Bioinformatics predicted and dual-luciferase gene reporter assay verified miR-3907 target genes. The protein expression levels of target genes in 18 MGC tissues and 6 para-carcinoma tissue samples were determined by immunohistochemical staining. miR-3907 over-expression, miR-3907 knock-down, target gene knock-down and miR-3907 knock-down with target gene knock-down were respectively performed in MGC cell. The mRNA and protein expressions were validated by real-time PCR and Western blotting after transfection. The cell proliferation and migration ability was detected by cell counting kit-8 and scratch experiment after transfection. The main statistical methods were Fisher's exact test, independent sample t test, two-factor repeated measure analysis of variance. Results: There were 22 differently up-regulated miRNAs and 5 differently down-regulated miRNAs in MGC tissues, of which miR-3907 was significantly up-regulated. Thrombospondin-1 (THBS1) was a target gene of miR-3907 according to bioinformatics and dual-luciferase gene reporter assay. The positive expression rate of THBS1 protein in para-carcinoma tissues (6/6) was significantly higher than that in MGC tissues (5/18), and the difference was statistically significant (P=0.003). Compared with the negative control group, the proliferation ability of the miR-3907 over-expression group was increased at 48 h and 72 h (F=3.70, 2.65; both P<0.01), and the migration rate at 24 h was significantly higher (54.6%±3.4% vs. 34.2%±0.6%; t=8.34, P<0.01). Compared with the negative control group, the proliferation ability of the miR-3907 knock-down group was decreased at 24 h, 48 h and 72 h (F=3.10, 2.17, 3.09; all P<0.05), and the migration rate at 24 h was significantly lower (40.8%±2.8% vs. 69.7%±2.7%; t=10.42, P<0.01). Compared with the negative control group, the THBS1 knock-down group promoted cell proliferation at 24 h, 48 h and 72 h (F=3.84, 3.79, 2.24; all P<0.05), and the migration rate at 24 h was significantly increased (82.5%±1.9% vs. 37.6%±5.1%; t=11.74, P<0.01). Compared with the control group, the miR-3907 knock-down with THBS1 knock-down group increased proliferation at 24 h and 48 h (F=3.97, 3.31; both P<0.05), and the migration healing rate at 24 h was significantly increased (56.9%±2.2% vs. 41.9%±4.3%; t=3.53, P<0.05). Conclusions: There are differently expressed miRNAs between MGC and para-carcinoma tissues, which may be related to the occurrence and development of MGC. miR-3907 in MGC tissues has a significant difference from that in para-carcinoma tissues. Moreover, miR-3907 can play a role in promoting proliferation and migration of MGC by inhibiting the expression of THBS1.


Assuntos
Carcinoma , MicroRNAs , Carcinoma/genética , Linhagem Celular Tumoral , Movimento Celular , Regulação Neoplásica da Expressão Gênica , Humanos , Glândulas Tarsais , MicroRNAs/genética
2.
Zhonghua Yan Ke Za Zhi ; 57(7): 531-539, 2021 Jul 11.
Artigo em Chinês | MEDLINE | ID: mdl-34256474

RESUMO

Objective: To analyze the protein expression differences of lacrimal gland adenoid cystic carcinoma (LACC) with high-grade transformation (HGT). Methods: Experimental study. A total of 8 paraffin tissue samples were collected in Tianjin Medical University Eye Hospital from December 2012 to January 2019. According to pathological examination, the samples were divided into the LACC group and the LACC-HGT group, with 4 cases in each group. The LACC group included 2 male samples and 2 female samples, with an average age of 53 years. The LACC-HGT group included 2 male samples and 2 female samples, with an average age of 44 years. Primary cells were cultured from fresh tumor tissue. Isobaric tags for relative and absolute quantification techniques were used to screen the differentially expressed proteins between the two groups, and bioinformatics analysis was conducted for the differentially expressed proteins. Microarray was used to screen differentially expressed mRNAs between LACC and LACC-HGT primary cells. The mass spectrum data were intersected with mRNA microarray data, and quantitative real-time (qRT) PCR was performed to verify the results. Proteomics and microarray data were compared using the independent sample t test. The qRT-PCR data were compared pairwise by one-way analysis of variance. Results: A total of 105 HGT-related differential proteins were detected in this study, including 50 up-regulated proteins and 55 down-regulated proteins. The significantly up-regulated proteins included hemoglobin subunit beta, hemoglobin subunit alpha 1, and collagen type Ⅵ alpha 2 chain; the significantly down-regulated proteins included Cereblon, adenosylhomocysteinase like 2, and ribosomal protein L39 pseudogene 5. Gene ontology analysis results showed that the LACC-HGT differential proteins were mainly located in the cytoplasm, vesicle cavity, and extracellular matrix, had organic acid binding and molecular carrier activity, and participated in the regulation of extracellular matrix composition, immunity, inflammation, apoptosis, and other biological processes. Pathway analysis showed that the LACC-HGT differential proteins were mainly involved in signal pathways such as mitogen-activated protein kinase signal pathway and extracellular matrix proteoglycans and glycan metabolism signal pathway. Protein complex prediction analysis screened out 4 up-regulated protein complexes and 1 down-regulated protein complex. There were 15 LACC-HGT differential proteins that overlapped with mRNA chip differential genes, of which 6 were tumor-related proteins including collagen type XIV alpha 1 chain (COL14A1), EMAP like 4 (EML4), inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), NDRG family member 2 (NDRG2), osteoglycin (OGN) an Ras homolog family member C (RhoC). The main function was the movement and migration of tumor cells. The qRT-PCR results showed that the relative expression levels of COL14A1, EML4, ITIH4, NDRG2, OGN, and RhoC in primary LACC-1, LACC-2, LACC-HGT-1, and LACC-HGT-2 cells were significantly different (F=1 675.98, 38.53, 27.37, 16.47, 13.38, 25.22, all P<0.01). For example, the relative expression of COL14A1 in primary LACC-HGT-1 (16.09±0.51) and LACC-HGT-2 (9.96±0.34) cells was significantly higher than that in primary LACC-1 (1.00±0.13) and LACC-2 (0.67±0.08) cells (all P<0.05). Conclusion: There are differentially expressed proteins between LACC-HGT and LACC, among which COL14A1, EML4, ITIH4, NDRG2, OGN, and RhoC may play an important role in LACC-HGT and can be used as potential targets of LACC-HGT in further study. (Chin J Ophthalmol, 2021, 57: 531-539).


Assuntos
Carcinoma Adenoide Cístico , Neoplasias Oculares , Doenças do Aparelho Lacrimal , Aparelho Lacrimal , Adulto , Carcinoma Adenoide Cístico/genética , Neoplasias Oculares/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteômica
3.
J Biol Regul Homeost Agents ; 30(1): 189-95, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27049091

RESUMO

This study was designed to determine the effects and compare laparoscopic intervention and open surgery in treating severe acute pancreatitis (SAP) and its relative aftercare, to improve the overall treatment of SAP. Ninety patients with SAP were enrolled from the 2nd Affiliated Hospital of Harbin Medical University from 2008 to 2014 and divided into a laparoscopic intervention group (25 cases) and an open surgery group (65 cases). Patients were asked for clinical symptoms, general hospital information, laboratory inspection, imageological examination, local and systemic complications, treatment and outcome. SAP patients’ relevant clinical indicators were compared between the two groups before and after the operation. Results revealed that there was no statistical significance in lesion range and main scoring indexes for reflecting the severity of the disease. For both groups statistical significance was found in blood loss (285.3±79.8 mL vs 362±91.6 mL), intensive care unit (ICU) monitoring time (9.04±6.35 d vs 12.48±8.34 d) and service time of breathing machine (9.47±6.24 d vs 12.98±8.25 d), and the laparoscopic operation group was superior to the open surgery group (p < 0.05). Besides, the laparoscopic operation group was also superior to the open surgery group in demand for main analgesics one week after the operation, as well as for recovery rate and incidence of complications (p < 0.05). Thus, it can be concluded that patients undergoing laparoscopic intervention are less likely to develop pulmonary infection and more likely to be cured in comparison with patients who receive open surgery. In addition, laparoscopic intervention results in less damage, lighter pain and fewer complications compared with open surgery.


Assuntos
Assistência ao Convalescente , Laparoscopia , Pancreatite/cirurgia , Cuidados Pós-Operatórios , Doença Aguda , Adulto , Idoso , Amilases/sangue , Analgésicos/uso terapêutico , Cálcio/sangue , Feminino , Humanos , Unidades de Terapia Intensiva , Laparoscopia/efeitos adversos , Masculino , Pessoa de Meia-Idade , Pancreatite/sangue , Pancreatite/tratamento farmacológico , Pancreatite/enzimologia , Complicações Pós-Operatórias/etiologia , Respiração Artificial , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
4.
Eur Rev Med Pharmacol Sci ; 24(20): 10338-10345, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33155189

RESUMO

OBJECTIVE: The aim of this study was to explore the relationship between CYP11B2 gene polymorphisms and eclampsia. PATIENTS AND METHODS: A total of 400 pregnant women treated in our hospital were enrolled in this study, including 200 normal pregnant women (pregnancy group) and 200 pregnant women with eclampsia (eclampsia group). Peripheral blood was collected from subjects of the two groups. Subsequently, genomic deoxyribonucleic acids (DNAs) were extracted and amplified via polymerase chain reaction (PCR) for detection of CYP11B2 rs4543, rs3802228 and rs104894072 polymorphisms. The expression level of CYP11B2 gene was measured as well. Additionally, the correlations of CYP11B2 gene polymorphisms with blood pressure and coagulation and renal function indexes were analyzed. RESULTS: The distribution of alleles of rs4543 locus in CYP11B2 gene was significantly different between eclampsia group and pregnancy group (p=0.027). The frequency of the allele C was significantly lower in eclampsia group than that of pregnancy group (p<0.05). There was a statistically significant difference in the genotype distribution of CYP11B2 rs3802228 (p=0.000) and rs104894072 (p=0.000) between eclampsia group and pregnancy group (p<0.05). Meanwhile, the frequency of AA genotype of rs3802228 and TG genotype of rs104894072 was remarkably higher in eclampsia group than that in pregnancy group (p<0.05). The distribution of the locus rs104894072 (p=0.044) in dominant model and rs3802228 (p=0.002) in recessive model in eclampsia group was different from that in pregnancy group (p<0.05). Eclampsia group showed remarkably elevated frequency of TT + TG of the locus rs104894072 in dominant model and lowered frequency of AG + GG of the locus rs3802228 in recessive model (p<0.05). Similarly, a significant difference was observed in the distribution of the haplotypes CGG (p=0.001) and TGT (p=0.048) in CYP11B2 gene between eclampsia group and pregnancy group (p<0.05). The linkage disequilibrium of the loci rs3802228 and rs104894072 was relatively high (D'=0.382). The polymorphism of the locus rs104894072 in CYP11B2 gene had an evident relation to CYP11B2 gene expression (p<0.05). Meanwhile, the expression of CYP11B2 gene was markedly higher in patients with GG genotype in eclampsia group (p<0.05). The polymorphism of CYP11B2 rs4543 was notably associated with PT level of patients in eclampsia group (p=0.000). Conversely, rs3802228 polymorphism was correlated with 24 h urine protein level (p=0.000). Besides, the proportion of patients with CGG haplotype was significantly larger among patients with systolic blood pressure of 140-160 mmHg (p<0.05). In addition, the proportion of patients with TGT haplotype was evidently greater among patients with systolic blood pressure >180 mmHg in eclampsia group (p<0.05). CONCLUSIONS: CYP11B2 gene polymorphisms are significantly correlated with the development and progression of eclampsia.


Assuntos
Citocromo P-450 CYP11B2/genética , Eclampsia/genética , Adulto , Citocromo P-450 CYP11B2/metabolismo , Eclampsia/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica/genética , Humanos , Polimorfismo Genético/genética , Gravidez
5.
Artigo em Chinês | MEDLINE | ID: mdl-31163553

RESUMO

Objective: To investigate the expression and clinical significance of long non-coding RNA FOXD2-AS1 in laryngeal squamous cell carcinoma and its effect on cancer cell proliferation. Method: Real-time quantitative polymerase chain reaction(RT-qPCR) was used to detect the expression of FOXD2-AS1 in 85 cases of laryngeal carcinoma. One-way ANOVA was used to determine relationships between its expression and clinicopathological parameters of laryngeal carcinoma. The prognostic significance of FOXD2-AS1 in head and neck cancer was explored using bioinformatics technology. SiRNA was used to interfere the expression of FOXD2-AS1 in TU686 laryngeal carcinoma cells. MTT and clonal formation assay were used to investigate the biological effect of FOXD2-AS1. MicroRNA binding to FOXD2-AS1 was investigated using double luciferase assay. Result: The expression of FOXD2-AS1 in laryngeal cancer tissues was significantly higher than that in normal tissues(t=10.012, P<0.05), and was associated with T staging of laryngeal cancer(χ=6.41, P=0.016). There were no relationships between FOXD2-AS1 expression and age, sex, smoking history, primary site of tumor and lymph node metastasis(N staging). Survival analysis of head and neck tumors in the TCGA database using GEPIA showed poor prognosis in patients with high FOXD2-AS1 expression(P=0.048). Suppressing FOXD2-AS1 via siRNA in TU686 cells decreased clonal formation ability(t=8.053, P<0.05) and MTT assay confirmed that interference of FOXD2-AS1 down regulated proliferation activity of TU686 cells(t=9.337, P<0.05). Double luciferase assay showed that FOXD2-AS1 could directly bind to miR-206, thus inhibiting the expression of miR-206. Further MTT assay indicated that inhibiting miR-206 attenuated the suppressing effect of si-FOXD2-AS1 on the proliferation of TU686 cells. Conclusion: FOXD2-AS1 is corelated with clinicopathological parameter of laryngeal squamous cell carcinoma and promotes cancer cell proliferation through targeting miR-206.


Assuntos
Neoplasias Laríngeas/genética , MicroRNAs/genética , RNA Longo não Codificante/genética , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Neoplasias Laríngeas/patologia , Estadiamento de Neoplasias , Prognóstico , RNA Interferente Pequeno
6.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 31(13): 1034-1035, 2017 Jul 05.
Artigo em Chinês | MEDLINE | ID: mdl-29798173

RESUMO

A 59 years old woman with chief complain of intermittent hemoptysis and shortness of breath was admitted to our hospital. Fiberoptic laryngoscope: no abnormality seen; enhanced computerized tomography of the neck showed that at the second trachea ring located a round nodule with a diameter of about 23 mm, flat on the sixth cervical vertebrae, consider vascular tumors. The immunohistochemistry: an inflammatory myofibroblastic tumor.


Assuntos
Granuloma de Células Plasmáticas/diagnóstico , Neoplasias da Traqueia/diagnóstico , Feminino , Granuloma de Células Plasmáticas/complicações , Hemoptise/etiologia , Humanos , Pessoa de Meia-Idade , Pescoço , Tomografia Computadorizada por Raios X , Neoplasias da Traqueia/complicações
7.
Yao Xue Xue Bao ; 24(2): 81-4, 1989.
Artigo em Chinês | MEDLINE | ID: mdl-2801141

RESUMO

The effective period of isolated working guinea pig heart perfused with Tris-sodium-pyruvate solution (Tris-SP) was shown to be 70 min. Perfluorotributylamine at a concentration of 0.5% added to Tris-SP prolonged the effective time to 90 min. 7-Bromoethyoxybenzene-tetrahydropalmatine (EBP) 10 mumol/L, and prazosin 0.1 mumol/L showed no obvious influence on the parameters in the isolated working guinea pig heart. Methoxamine 1 mumol/L and dopamine 1 mumol/L produced marked changes on LVP, ABF, +/- dp/dtmax and T-CO. It is suggested that the alpha 1-adrenoceptor was partially associated with the positive chronotropic action of the heart. Effects of methoxamine and dopamine on the parameters were antagonized by EBP. It shows that the antagonistic affects of EBP on methoxamine and dopamine are concerned with its antagonistic effect on alpha 1-adrenoceptor and dopamine receptor. This is consistent with previous results in rabbit aortic strips and rat anococcygeus muscles.


Assuntos
Alcaloides/farmacologia , Antiarrítmicos , Alcaloides de Berberina/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Animais , Circulação Coronária/efeitos dos fármacos , Dopamina/farmacologia , Cobaias , Técnicas In Vitro , Masculino , Metoxamina/farmacologia
8.
Yao Xue Xue Bao ; 28(11): 812-6, 1993.
Artigo em Chinês | MEDLINE | ID: mdl-7516605

RESUMO

Standard microelectrode and two-microelectrodes voltage clamp techniques were used to study the effects of linesinine (Lien), an alkaloid extracted from the green seed embryo of Nelumbo nucifera Gaertn, on slow action potentials (AP) and slow inward current (Isi). Lien 10-100 mumol/L was shown to concentration-dependently decrease the action potential amplitude (APA), the maximal velocity of phase 0 depolarization (Vmax) and prolong the sinus cycle length (SCL) of slow AP in isolated sinoatrial node (SAN) pacemaker cells of rabbits. On both slow APs of rabbit SAN cells and guinea pig papillary muscles partly depolarized by high K+, Bay K 8644 0.03 mumol/L markedly increased the APA and Vmax, which were obviously antagonized by Lien 10 mumol/L. Moreover, Lien 1-100 mumol/L was found to inhibit the Isi of canine cardiac Purkinje fiber in concentration-dependent manner. Lien 3 and 100 mumol/L reduced the peak value of Isi by 14% and 88% respectively. The results suggest that Lien possesses calcium antagonistic effects.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Isoquinolinas/farmacologia , Fenóis/farmacologia , Ramos Subendocárdicos/efeitos dos fármacos , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/antagonistas & inibidores , Potenciais de Ação/efeitos dos fármacos , Animais , Canais de Cálcio/efeitos dos fármacos , Cães , Feminino , Cobaias , Coração/fisiologia , Masculino , Coelhos , Ratos
9.
Yao Xue Xue Bao ; 32(3): 161-5, 1997.
Artigo em Chinês | MEDLINE | ID: mdl-11327013

RESUMO

Standard microelectrode technique and the whole-cell clamp technique were used to investigate the effects of tetrandrine and rotundine on the action potential of rabbit sinus node dominant pacemaker cell and calcium currents of ventricular myocytes from guinea-pig. The results indicate that: tetrandrine 1-200 mumol.L-1 and rotundine 3-300 mumol.L-1 decreased the action potential amplitude(APA), the maximal upstroke velocity (Vmax), spontaneous depolarizing velocity of phase 4(SP4) and prolonged the sinus circle length(SCL) in a dose-dependent manner. Tetrandrine 0.1 mumol.L-1 in combination with rotundine 0.3 mumol.L-1 was shown to effectively reduce the ICa of ventricular myotytes from guinea-pig, the rate of inhibition is 19.6%. The results suggest that the two drugs have a good synergistic effect on inhibiting calcium current. These results might also put forward a valuable theoretic base for using the two drugs together in treating patients.


Assuntos
Alcaloides/farmacologia , Benzilisoquinolinas , Alcaloides de Berberina/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Miocárdio/citologia , Nó Sinoatrial/fisiologia , Potenciais de Ação/efeitos dos fármacos , Animais , Canais de Cálcio/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Feminino , Cobaias , Masculino , Coelhos , Nó Sinoatrial/citologia
10.
Yao Xue Xue Bao ; 25(4): 293-6, 1990.
Artigo em Chinês | MEDLINE | ID: mdl-2281790

RESUMO

The changes of monophasic action potential (MAP) in ischemic and reperfused feline ventricle in situ were studied. When the feline coronary artery was ligated the MAPD50 was found to be markedly shortened, the T wave and S-T segment were elevated evidently. Within seconds of releasing the coronary occlusion ventricular fibrillation and death occurred in all animals. Intravenous injection of BTHP markedly prolonged the MAPD50 and MAPD90 and reduced the heart rate, while no influence on T wave and S-T segment were observed. After occlusion of the coronary artery, the T wave and S-T segment only increased slightly and the MAPD50 recovered to its control level. During reperfusion the occurrence of ventricular fibrillation was significantly reduced. In contrast, prazosin, verapamil and propranolol did not show significant effect on changes of MAP, but BTHP and Pra, Ver and Pro all showed protective effect on feline ischemic and reperfused myocardia by ligation and reperfusion of the coronary artery with decrease of the number of arrhythmia, ventricular fibrillation and death. The order of antiarrhythmic action of these agents was BTHP = Pra greater than Ver greater than Pro. The total incidence of ventricular fibrillation reduced from the control values of 100% in ischemia/reperfusion heart to 0% (BTHP and Pra), 20% (Ver) and 40% (Pro).


Assuntos
Alcaloides/farmacologia , Antiarrítmicos/farmacologia , Arritmias Cardíacas/fisiopatologia , Alcaloides de Berberina/farmacologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Potenciais de Ação/efeitos dos fármacos , Animais , Arritmias Cardíacas/etiologia , Gatos , Doença das Coronárias/fisiopatologia , Eletrocardiografia/efeitos dos fármacos , Feminino , Masculino
11.
Yao Xue Xue Bao ; 36(4): 250-3, 2001 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-12580050

RESUMO

AIM: To investigate the effect of 4-aminopyridine (4-AP) on ion channels of myocytes. METHODS: L-type calcium channel and sodium channel currents were recorded in guinea pig single ventricular myocyte using whole-cell patch-clamp techniques. RESULTS: 4-AP, 0.1, 0.5 and 1.0 mmol.L-1 were shown to inhibit L-type calcium channel currents (ICa, L) and sodium channel currents (INa) concentration-dependently. The percentage of inhibition were (11.6 +/- 1.7)%, (37.5 +/- 8.3)% and (54.5 +/- 6.9)% (P < 0.01) respectively for ICa, L, and (22.1 +/- 14.3)% (P < 0.05), (39.4 +/- 8.8)% and (62.3 +/- 6.8)% (P < 0.01) respectively for INa. 4-AP 0.5 mmol.L-1 shifted the I-V curves of ICa, L and INa upwardly. CONCLUSION: 4-AP blocked L-type calcium channel and sodium channels in guinea-pig ventricular myocytes concentration-dependently.


Assuntos
4-Aminopiridina/farmacologia , Canais de Cálcio/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Sódio/efeitos dos fármacos , Animais , Separação Celular , Feminino , Cobaias , Ventrículos do Coração/efeitos dos fármacos , Masculino , Técnicas de Patch-Clamp
12.
Yao Xue Xue Bao ; 35(12): 893-7, 2000 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-12567909

RESUMO

AIM: The L-Type calcium currents were investigated in normal, hypertrophied and amiloride-treated rat ventricular myocytes so as to clarify the possible cause of the action potential lengthening that has been reported in thyroxine-induced hypertrophy. The interactions between agents such as thyroxine, Ang II and phenylephrine which induced hypertrophy with amiloride on the calcium current were analyzed. METHODS: Myocardial hypertrophy was induced by i.p. L-thyroxine in rats. The cell length, cell width and cell area were measured by image analysis technique. For recording ICaL, the whole cell patch clamp technique was used. Potassium currents were suppressed by replacing K+ ions with Cs+ ions in intracellular media, and sodium current was blocked by 50 mumol.L-1 tetrodotoxin. RESULTS: The Ca2+ current was found to be larger in hypertrophied cells (783pA) than in normal cells (433pA) and in amiloride-treated cells (429pA). However, no significant difference was observed in current density (6.54, 8.33, 5.74 pA/pF) in normal, hypertrophied and amiloride-treated cells. ICa displayed the same voltage dependence in three cell types. The potential giving 50% of activation (V1/2) moved towards more negative and the slope of activation curve was smaller in hypertrophied cells than in normal cells and amiloride cells. When expressed as percentages, the maximal increases in ICa were obtained with 1 mumol.L-1 Ang II and 100 mumol.L-1 phenylephrine in normal cells (+45.5% and +81.8%). Thyroxine 100 mumol.L-1 showed no effect on ICa. After giving amiloride, Ang II and phenylephrine did not increase the amplitude of ICa. CONCLUSION: At the dose of 0.5 mg.kg-1.d-1, amiloride (p.o.) was shown to prevent the amplitude of ICa from increasing and to be effective against increases of amplitude of ICa by Ang II and phenylephrine.


Assuntos
Amilorida/farmacologia , Canais de Cálcio Tipo L/fisiologia , Cardiomegalia/fisiopatologia , Miócitos Cardíacos/efeitos dos fármacos , Angiotensina II/antagonistas & inibidores , Animais , Canais de Cálcio Tipo L/efeitos dos fármacos , Cardiomegalia/induzido quimicamente , Separação Celular , Feminino , Masculino , Miócitos Cardíacos/fisiologia , Distribuição Aleatória , Ratos , Ratos Wistar , Tiroxina
13.
Yao Xue Xue Bao ; 30(9): 651-4, 1995.
Artigo em Chinês | MEDLINE | ID: mdl-8701739

RESUMO

The present study indicates that iv tetrandrine may transiently decrease blood pressure, while other hemodynamic parameters such as LVP, +/- dp/dtmax, LVEDP, HR and CO may not be significantly altered. During coronary occlusion three of five dogs developed ventricular fibrillation (VF) and died in the control group, i.e. incidences of VF and mortality were 60%. While tetrandrine (Tet) appeared to reduce the severity of ischemic injury. It may alleviate arrhythmia and prevent VF and death in four of the five dogs. Tet also attenuated Ca2+ accumulation in myocardial cell, reduced melondialdehyde (MDA) production in ischemic myocardial and decreased CPK release in comparison with the control. It appears that Tet may have significant protective effects against ischemia induced cardiac damage in anesthetized dogs.


Assuntos
Alcaloides/uso terapêutico , Benzilisoquinolinas , Bloqueadores dos Canais de Cálcio/uso terapêutico , Traumatismo por Reperfusão Miocárdica/prevenção & controle , Animais , Cálcio/metabolismo , Creatina Quinase/sangue , Cães , Feminino , Masculino , Malondialdeído/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miocárdio/metabolismo
14.
Yao Xue Xue Bao ; 25(7): 481-4, 1990.
Artigo em Chinês | MEDLINE | ID: mdl-2085121

RESUMO

The mechanism of antiarrhythmic action and the electrophysiologic effects of 7-bromoethoxybenzene-tetrahydroptamine (EBP) have been studied using conventional microelectrode technique. The effect of EBP on the membrane ISi and I(X) currents were investigated in the canine cardiac purkinje fibres using the double microelectrode voltage clamp methods. EBP was shown to increase the duration of action potential at 20 and 90% of repolarization of isolated guinea pig papillary muscles. However, the amplitude of action potential, the resting potential and the overshoot and maximum rate of 0 phase depolarization (Vmax) remained unchanged. The membrane potential was held at 40 mV and command potential at -15 mV, 0.3 Hz 500 ms. After 10 min of perfusion of EBP 30 mumol/L, the slow inward current (ISi) was reduced markedly. When the holding potential was held at -20 mV, and the command potential at +10 mV, EBP (10-100 mumol/L) exerted a depressed effect on the delayed (outward) rectifier current (I(X)) in a dose-dependent manner. It may be concluded that the antiarrhythmic effects of EBP is mainly related to decrease the automaticity and prolong the duration of action potential at 20-90% of repolarization of isolated guinea pig papillary muscles.


Assuntos
Alcaloides/farmacologia , Antiarrítmicos , Alcaloides de Berberina/farmacologia , Potenciais de Ação/efeitos dos fármacos , Animais , Cães , Eletrofisiologia , Feminino , Cobaias , Técnicas In Vitro , Masculino , Microeletrodos , Músculos Papilares/efeitos dos fármacos , Ramos Subendocárdicos/efeitos dos fármacos
15.
Yao Xue Xue Bao ; 31(11): 867-71, 1996.
Artigo em Chinês | MEDLINE | ID: mdl-9863258

RESUMO

The effects of benzyltetrahydropalmatine (BTHP) on delayed rectified K+ currents (Ik) expressed in Xenopus oocytes and Ik of toad (Bufo bufo gargarizans) oocytes were studied. The Ik expressed in Xenopus oocytes was measured after microinjection of mRNA isolated from carp fish (C anratus L.) brains with double -microelectrode voltage clamp technique. The maximum and mean value of Ik expressed in Xenopus oocytes were 600 nA and 360 +/- 104 nA, respectively. BTHP reduced the current amplitude of Ik expressed in Xenopus oocytes in 10-1000 mumol.L-1 dose-dependently, EC50 was 29 mumol.L-1. Also, the reduction of Ik of toad oocytes was 9.1%, 29.1%, 54.7% and 68.6% by BTHP 10, 30, 100 and 1000 mumol.L-1, respectively, EC50 was 33 mumol.L-1. The results showed that BTHP possesses an inhibitory effect on Ik, the main ion mechanism of antiarrhythmic action of BTHP.


Assuntos
Alcaloides de Berberina/farmacologia , Bloqueadores dos Canais de Potássio , Animais , Fusão Gênica Artificial , Química Encefálica , Bufo bufo , Carpas , Oócitos/fisiologia , Técnicas de Patch-Clamp , RNA Mensageiro/biossíntese , Xenopus laevis
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