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1.
Journal of Preventive Medicine ; (12): 302-306, 2022.
Article in Chinese | WPRIM | ID: wpr-920772

ABSTRACT

Objective@#To examine the effects of bisphenol A (BPA), bisphenol S ( BPS ), bisphenol F ( BPF ) and bisphenol AF ( BPAF ) on the proliferation and oxidative stress of BRL 3A rat liver cells, and to preliminarily evaluate their mutagenicities.@*Methods@#In vitro cultured BRL 3A rat liver cells were treated with BPA, BPS, BPF and BPAF at concentrations of 0, 5, 10, 25, 50, 100, 150 and 200 μmol/L for 48 h, respectively. Then, the cell viability was determined using the CCK-8 assay, and the half maximal inhibitory concentration ( IC50 ) was calculated. The minimum inhibitory concentration for BRL 3A cell proliferation was screened, and the intracellular reactive oxygen species ( ROS ) was measured in BRL 3A cells using the 2',7'-dichlorodihydrofluorescein diacetate ( DCFH-DA ) assay. In addition, the effects of BPA, BPS, BPF and BPAF at concentrations of 1 000, 200, 40, 8 and 1.6 μg/plate on the mutant colonies of histidine-deficient Salmonella typhimurium ( TA1535, TA97a, TA98, TA100 and TA102 ) were tested using the Ames test.@*Results@#Treatment with BPA and BPF at concentrations of 100 to 200 μmol/L and with BPAF at concentrations of 25 to 200 μmol/L inhibited BRL 3A cell survival at a concentration-dependent manner, while exposure to BPS at concentrations of 5 to 200 μmol/L resulted in no changes in BRL 3A cell survival. The IC50 values of BPA, BPS, BPF and BPAF were 131.7, >200, 187.5 and 21.6 μmol/L against BRL 3A cells, respectively. Treatment with BPS at 100 μmol/L or BPAF at 25 μmol/L caused no significant changes in the ROS level; however, exposure to BPA at 100 μmol/L and BPF at 100 μmol/L significantly increased the ROS level. Ames test showed that BPA, BPS, BPF and BPAF did not induce mutagenicity in TA1535, TA97a, TA98, TA100 or TA102 strains.@*Conclusions@#BPAF shows the highest cytotoxicity to BRL 3A cells, and low-concentration exposure to BPS has few effects on BRL 3A cells. The cytotoxicity of bisphenols against BRL 3A cells may be associated with the induction of oxidative stress. None of the four bisphenols show mutagenic effects under the present experimental conditions.

2.
Chinese Journal of Experimental Traditional Medical Formulae ; (24): 35-39, 2019.
Article in Chinese | WPRIM | ID: wpr-798491

ABSTRACT

Objective:To campare the hepatotoxicity on BRL and nephrotoxicity on NRK caused by dichloromethane site of Genkwa Flos before and after being processed with vinegar. Method:BRL of normal hepatocytes and NRK of normal renal cells in rats were selected as the subjects.Thiazolyl blue tetrazolium bromide method(MTT) was adopted to evaluate the effect of dichloromethane sites of raw and vinegar-processed products on cell activity of NRK and BRL.The levels or contents of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),glutathione(GSH),lactate dehydrogenase(LDH),blood urea nitrogen(BUN) were determined in cell culture supernatant and splitting supernatant for evaluation of their oxidative damage effect. Result:Compared with the blank group,dichloromethane site of raw products could obviously inhibit the cell activity of NRK and BRL,and increase the levels of AST,ALT,ALP and LDH(PPPPConclusion:Processing with vinegar can attenuate the hepatotoxicity and nephrotoxicity on NRK and BRL caused by dichloromethane site of Genkwa Flos,it can improve hepatic and renal function and antioxidant capacity.

3.
Chinese Pharmacological Bulletin ; (12): 680-685, 2018.
Article in Chinese | WPRIM | ID: wpr-705107

ABSTRACT

Aim To investigate the effect of salvianolic acid B(Sal B) on the attenuation of rat hepatocyte in-jury induced by hypoxia/reoxygenation(H/R) and its possible molecular mechanism. Methods Rat hepato-cytes BRL-3A were cultured in vitro. H/R injury mod-el was established and then BRL-3A cells were pretrea-ted with Sal B. The viability of cells was measured by CCK-8 assay;the expression of ALT and AST was de-tected by microplate assay; the levels of TNF-α and IL-1β were determined by ELISA; the apoptosis was detected by flow cytometry;the protein and mRNA lev-els of SIRT1, NF-κB p65, p53, Bax and Bcl-2 were measured by Western blot and qPCR. Results H/R intervention decreased the viability and increased the apoptosis of cells;the production of ALT, AST, TNF-α and IL-1β was elevated;the protein and mRNA lev-els of SIRT1, Bcl-2 were reduced, but the levels of NF-κB p65, p53 and Bax increased. After pretreated with Sal B, the viability of cells increased while the apoptosis decreased; the expression of ALT, AST, TNF-α and IL-1β was inhibited;moreover,the protein and mRNA levels of SIRT1,Bcl-2 were enhanced,and the levels of NF-κB p65, p53 and Bax decreased sig-nificantly. Conclusion Sal B may attenuate rat hepa-tocyte injury induced by H/R via the SIRT1/NF-κB/p53 pathway.

4.
Chinese Journal of Organ Transplantation ; (12): 239-243, 2017.
Article in Chinese | WPRIM | ID: wpr-620867

ABSTRACT

Objective To investigate the effect of CaMK Ⅱ expression on apoptosis of rat hepatocytes BRL-3A.Methods Rat BRL-3A cells were stable passage were cultured.The CaMK Ⅱ γ protein (LV-CaMK Ⅱ γ group) and CaMK Ⅱ γshRNA (shRNA group) lentiviral expression systems were constructed.The corresponding blank vectors (LV-NC group and shRNA-NC group) and normal saline (CON group) were perfused into the control groups.The expression levels of CaMK Ⅱ,Cyt C and MF proteins were detected by Western blotting,and the apoptosis rate of BRL-3A cells was measured by Tunel method.Results The protein expression of CaMK Ⅱ,Cyt C and AIF in LV-CaMK Ⅱ γ group was significantly higher than that in CON group (P<0.05).The protein expression of CaMK Ⅱ,Cyt C and AIF in shRNA group was significantly lower than that in CON group (P< 0.05).There was no significant difference among CON group,LV-NC group and shRNA-NC group (P>0.05).At the same time point,the apoptosis rate of hepatocytes in LV-CaMK Ⅱ γ group was significantly higher than that in CON group (P<0.05).At the same time point,the apoptosis rate of hepatocytes in shRNA group was significantly higher than in CON group (P<0.05).There was no significant difference in the apoptosis of hepatocytes among CON group,LV-NC group and shRNA-NC group (P>0.05).Conclusion The specific CaMK Ⅱ signaling pathway can inhibit the apoptosis of BRL-3A cells,while the enhanced CaMK Ⅱ signaling pathway promotes the apoptosis of BRL-3A cells.

5.
Acta Anatomica Sinica ; (6): 150-155, 2017.
Article in Chinese | WPRIM | ID: wpr-844677

ABSTRACT

Objective: To explore the effect of C7orf42 on cell proliferation of rat hepatocyte line BRL-3A in vitro. Methods: The expression of C7orf42 was knocked down by siRNA, and MTT and EdU assay were used to discover the effect of C7orf42 on cell proliferation at 48 hours after transfection. Flow cytometry was used to observe the effect of cell cycle progression. Real-tme PCR and Western blotting were used to detect the changes in the expression of cell proliferation-associated gene. Results: MTT results showed that the cell viability of the interference group (C7BRL-siR3) was significantly lower than that of the negative control group (NC) at 48 hours after transfection (P < 0. 05). Meanwhile, the percentage of EdU-labeling cells was also significantly decreased (P < 0. 05). At the same time, the flow cytometry results showed that the number of cells in division phase (S + G2/M) of the interference group was significantly reduced in parallel (P < 0. 05). Further, the interference group down-regulated the expression levels of cell proliferation-related genes and proteins of JUN, MYC, CCND1 and CCNA2. Conclusion: C7orf42 may promote cell proliferation via regulating the expression of JUN, MYC, CCND1 and CCNA2 in rat hepatocyte line BRL-3A.

6.
Journal of Veterinary Science ; : 63-70, 2016.
Article in English | WPRIM | ID: wpr-110764

ABSTRACT

Gap junctions mediate direct communication between cells; however, toxicological cascade triggered by nonessential metals can abrogate cellular signaling mediated by gap junctions. Although cadmium (Cd) is known to induce apoptosis in organs and tissues, the mechanisms that underlie gap junction activity in Cd-induced apoptosis in BRL 3A rat liver cells has yet to be established. In this study, we showed that Cd treatment decreased the cell index (a measure of cellular electrical impedance) in BRL 3A cells. Mechanistically, we found that Cd exposure decreased expression of connexin 43 (Cx43), increased expression of p-Cx43 and elevated intracellular free Ca2+ concentration, corresponding to a decrease in gap junctional intercellular communication. Gap junction blockage pretreatment with 18β-glycyrrhizic acid (GA) promoted Cd-induced apoptosis, involving changes in expression of Bax, Bcl-2, caspase-3 and the mitochondrial transmembrane electrical potential (Δψm). Additionally, GA was found to enhance ERK and p38 activation during Cd-induced activation of mitogen-activated protein kinases, but had no significant effect on JNK activation. Our results indicated the apoptosis-related proteins and the ERK and p38 signaling pathways may participate in gap junction blockage promoting Cd-induced apoptosis in BRL 3A cells.


Subject(s)
Animals , Rats , Apoptosis/drug effects , Cadmium/toxicity , Calcium/metabolism , Cell Communication/drug effects , Connexin 43/genetics , Enzyme Activation/drug effects , Gap Junctions/drug effects , Gene Expression Regulation/drug effects , Hepatocytes/cytology , Signal Transduction/drug effects
7.
Chinese Journal of Natural Medicines (English Ed.) ; (6): 521-528, 2015.
Article in English | WPRIM | ID: wpr-812515

ABSTRACT

The aim of the present study was to determine the preventive effects of the polysaccharide of Larimichthys crocea swim bladder (PLCSB) on CCl4-induced hepatic damage in ICR mice. The in vitro preventive effects of PLCSB on CCl4-induced liver cytotoxic effect were evaluated in BRL 3A rat liver cells using the MTT assay. The serum levels of AST, ALT, and LDH in mice were determined using commercially available kits. The levels of IL-6, IL-12, TNF-α, and IFN-γ were determined using ELISA kits. The pathological analysis of hepatic tissues was performed with H and E staining, and the gene and protein expressions were determined by RT-PCR and Western blotting, respectively. PLCSB (20 μg·mL(-1)) could increase the growth of BRL 3A rat liver cells treated with CCl4. The serum levels of AST, ALT, and LDH were significantly decreased when the mice were treated with two doses of PLCSB, compared with the control mice (P < 0.05). PLCSB-treated groups also showed reduced levels of the serum pro-inflammatory cytokines IL-6, IL-12, TNF-α, and IFN-γ. PLCSB could decrease the liver weight, compared to the CCl4-treated control mice. The histopathology sections of liver tissues in the 100 mg·kg(-1) PLCSB group indicated that the animals were recovered well from CCl4 damage, but the 50 mg·kg(-1) PLCSB group showed necrosis to a more serious extent. The 100 mg·kg(-1) PLCSB group showed significantly decreased mRNA and protein expression levels of NF-κB, iNOS, and COX-2, and increased expression of IκB-α compared with the CCl4-treated control group. In conclusion, PLCSB prevented from CCl4-induced hepatic damage in vivo.


Subject(s)
Animals , Male , Animal Structures , Chemistry , Biological Products , Pharmacology , Therapeutic Uses , Carbon Tetrachloride , Carbon Tetrachloride Poisoning , Drug Therapy , Metabolism , Pathology , Chemical and Drug Induced Liver Injury , Metabolism , Pathology , Cyclooxygenase 2 , Metabolism , Cytokines , Blood , I-kappa B Proteins , Metabolism , Inflammation Mediators , Blood , Liver , Metabolism , Pathology , Mice, Inbred ICR , NF-KappaB Inhibitor alpha , NF-kappa B , Metabolism , Necrosis , Nitric Oxide Synthase Type II , Metabolism , Perciformes , Polysaccharides , Pharmacology , Therapeutic Uses , RNA, Messenger , Metabolism
8.
Basic & Clinical Medicine ; (12): 1320-1324, 2015.
Article in Chinese | WPRIM | ID: wpr-481249

ABSTRACT

Objective_To study the effect of human insulin on cell cycle progression and apoptosis of rat liver cell line BRL-3A in vitro.Methods_MTT method was used to observe the effect of insulin on cell activity, and flow cytometry was used to detect cell apoptosis and cell cycle.qRT-PCR was used to evaluate the expression of related genes.Results_Human insulin induced the proliferation of BRL-3A cells in a dose-dependent manner ( P<0.05 or P<0.01);After 3 days treated by human insulin (500 nmol/L), the proportion of cells in G0/G1 phases re-markably decreased (P<0.05).Moreover, pro-apoptotic BAX was down-regulated (P<0.05), while cell prolif-eration-related gene CCNA2 was up-regulated (P<0.05).Conclusions_Human insulin may inhibit the apoptosis of BRL-3 A cell line and induce proliferation due to the down-regulated expression of BAX and up-regulated expres-sion of CCNA2 .

9.
Tianjin Medical Journal ; (12): 853-858, 2014.
Article in Chinese | WPRIM | ID: wpr-474052

ABSTRACT

Objective To explore the inhibitory effects of endogenous hydrogen sulfide, a novel and important gas-eous transmitter generated in mammalian tissues mainly by cystathionine β-synthase (CBS) or cystathionineγ-lyase (CSE) on the apoptosis of the rat hepatic BRL cell line in physiological condition. Methods BRL cells were cultured, and divid-ed randomly into several groups in different phases of the experiment, including negative-siRNA (control) group, CBS siRNA (CBS 1~3) group and CSE siRNA (CSE 1~3) group, which were used to select the most efficient sequences of siRNAs at 48 or 24-hour transfection. Solution group and (CBS+CSE) siRNA group were added to detect the variation of apoptosis. The BRL cell line was observed and evaluated at 0, 4, 8, 12, and 24 hrs after siRNA transfection. When the mechanisms of the apoptosis were detected, CBS/CSE siRNAs were transfected individually or jointly into BRL cells, and compared with nega-tive-siRNA group to examine the variation. The genic and protein expression of CBS/CSE were detected by RT-PCR and Western blot assay. After transfection of CBS/CSE siRNA, the apoptosis of BRL cells was detected by Hoechst stain and flow cytometry (FCM). The mitochondrial membrane potential (MMP) changes were observed by fluorescent staining. Western blot assay was used to examine the protein expression of intracytoplasm cytochrome C (Cyt C) and cleaved-caspase 3. Re-sults CBS and CSE were observed in BRL cells. After transfection of CBS/CSE siRNA, endogenous H2S generation de-creased and the apoptosis of BRL cells increased. Accordingly, the expression of intracytoplasm-Cyt C and cleaved-caspase 3 increased. Conclusion The inhibition of endogenous H2S synthesis induced the apoptosis of BRL cells under physiologi-cal condition, which may be involved in mitochondrial pathway of apoptosis.

10.
Article in English | IMSEAR | ID: sea-163696

ABSTRACT

The role of PDE-4 inhibitor etazolate, was evaluated in the presence of PDE-7 inhibitor, BRL-50481, in animal models of epilepsy. Seizures were induced in the animals by subjecting them to injection of chemical convulsants, Pilocarpine, Kainic acid (KA) and maximal electroshock (MES). The combination of etazolate and BRL50481 treated mice showed a significant (P<0.001) quick onset of action, jerky movements and convulsion when compared to gabapentin. The combination of etazolate and sGC inhibitor, methylene blue (MB) treated mice showed a significant (P<0.001) delay in onset of action, jerky movements and convulsion when compare to gabapentin as well as against the combination of etazolate with BRL 50481.The present study mainly highlights the individual effects of etazolate and combination with BRL-50481 potentiates (P<0.001) the onset of seizure activity against all models of convulsion. The study mainly comprises the onset of seizures, mortality/recovery, percentage of prevention of seizures (anticonvulsant) and total duration of convulsive time. The total convulsive time was prolonged significantly (P<0.05 and P<0.01) in combination of methylene blue with etazolate treated (28.59% and 35.15 %) groups, compared to DMSO received group (100%) in the MES model. In the same way, the combination of calcium channel modulator (CCM) and calcium channel blocker (CCB) amiodarone and nifedipine respectively, with etazolate showed a significant (P<0.001) delay in onset of seizures, compared to DMSO and etazolate treated groups in all models of epilepsy. This confirms that both CCM and CCB possess anticonvulsant activity. Finally, the study reveals that identification of new cAMP mediated phosphodiesterases family members offers a potential new therapy for epilepsy management in future.

11.
Braz. j. vet. res. anim. sci ; 48(1): 38-45, 2011. tab
Article in English | LILACS | ID: lil-591492

ABSTRACT

The present work was carried out to evaluate the in vitro development of bovine embryo co-cultured in granulosa, oviduct, BRL or VERO cells co-cultures, supplemented with 5% or 10% of Fetal Calf Serum (FCS). Cummulus oocyte complexes were aspirated, matured and fertilized in vitro. Embryonic structures were divided into eight treatments. They were placed in culture media TCM 199 containing granulosa, oviduct, BRL or VERO cells, each of them added with 5% or 10% FCS. The conditions for the co-culture were 38.5 ºC, 5% CO2 in air and high humidity for ten consecutive days. Cleavage, blastocyst and hatching rates did not differ (p > 0.05) in co-culture with primary cells (granulosa and oviduct) when FCS concentration increased from 5 to 10%. However, in continuous cells co-culture (BRL and VERO), when FCS concentration increased from 5% to 10%, the blastocyst development rate decreased significantly (p < 0.05) from 33.6 to 16.3% and from 40 to 16.5% in embryo co-culture with BRL and VERO cells, respectively.


O presente trabalho foi realizado com o objetivo de avaliar o desenvolvimento in vitro de embriões bovinos co-cultivados em células da granulosa, do oviduto, BRL e VERO, suplementados com 5% ou 10% de Soro Fetal Bovino (SFB). Os complexos cummulus oócitos foram aspirados, maturados e fecundados in vitro. As estruturas embrionárias foram divididas em oito tratamentos: co-cultivo em TCM 199 contendo células da granulosa, do oviduto, BRL ou VERO adicionadas com 5% ou 10% de SFB. As condições de cultivo foram 38.5 ºC, 5% CO2 em ar e alta humidade por dez dias consecutivos. Os índices de clivagem, blastocisto e eclosão não diferiram (p > 0,05) no co-cultivo com células primárias (granulosa e oviduto) quando a concentração de SFB aumentou de 5 para 10%. Entretanto, no co-cultivo com células de linhagens contínuas (BRL e VERO), quando a concentração de SFB aumentou de 5% para 10%, os índices de blastocistos diminuíram significativamente (p < 0,05) de 33,6 para 16,3 % e de 40 para 16,5% nos embriões bovinos co-cultivados com células VERO e BRL, respectivamente.


Subject(s)
Animals , Cattle , Blastocyst , Cattle/embryology , Coculture Techniques , Fallopian Tubes , Granulosa Cells , Vero Cells
12.
Chinese Journal of Information on Traditional Chinese Medicine ; (12)2006.
Article in Chinese | WPRIM | ID: wpr-579713

ABSTRACT

Objective To study the effect of modified Xiaochaihu Decoction on NF-kB and HSP70 of BRL cell induced by cisplatin. Methods BRL Cells were divided into control group, cisplatin group, high and low dose of modified Xiaochaihu decoction. Complete cell protein dot blot technique and immunohistochemisth analysis were appllied to detect the change of NF-kB and HSP70. Results There was a significant increase in NF-kB and decrease in HSP70 of BRL cell induced by cisplatin compared with control group. There was a significant decrease of NF-kB in modified Xiaochaihu decoction group compared with cisplatin group. There were increases of the expression of HSP70 in both high and low dose group, but only the high dose group demonstrated significant difference. Conclution The expression of NF-kB of BRL cell induced by cisplatin can be inhibited while the expression of HSP70 can be enhenced by modified Xiaochaihu decoction. It may be one of important mechanisms of relieving cell oxidize lesion and inhibiting apoptosis by modified Xiaochaihu decoction.

13.
Chinese Journal of Pharmacology and Toxicology ; (6): 33-38, 2006.
Article in Chinese | WPRIM | ID: wpr-408831

ABSTRACT

AIM To observe whether acute stimulation of BRL 37344, a β3-adrenergic receptor (β3-AR) agonist, has the same effects of exacerbating hemodynamics and increasing in β3-AR expression on rats with failing heart as chronic administration. METHODSRats received two doses of isoprenaline (Iso, 340 mg·kg-1, sc, with a 24-h interval) to prepare heart failure model. After 8 weeks, rats were given iv BRL 37344 0.4 nmol·kg-1·min-1 for 10 min. Hemodynamics were measured at 0, 10, 30 min, 1, 2, 3 h, 1, 2 and 7 d after BRL 37344. Levels of β-AR mRNA in myocardium were measured at 0, 1, 2 and 7 d after BRL 37344 by reverse transcription-polymerase chain reaction. RESULTSCompared with Iso group, heart rate, left ventricular end systolic pressure and +dp/dtmax were significantly higher, and left ventricular end diastolic pressure was significantly lower during 1-3 h after BRL 37344 injection in Iso+BRL group. Then, they were restored to the same level as that prior to BRL 37344 injection. Compared with normal control, the levels of β1-, β2- and β3-AR mRNA displayed no significant change in BRL group;the level of β1-AR mRNA was lower and the level of β3-AR mRNA was higher in Iso group. In Iso+BRL group, much more lower β1-AR mRNA level and much higher β3-AR mRNA level were shown on d 2 and d 7 than Iso group. CONCLUSION Acute administration of β3-AR agonist has a shorter improved hemodynamics. But it caused the same result as chronic administration in reduction of β1-AR mRNA and increment of β3-AR mRNA in failure hearts, which may aggravate the cardiac functions.

14.
Korean Journal of Obstetrics and Gynecology ; : 701-705, 1997.
Article in Korean | WPRIM | ID: wpr-25549

ABSTRACT

Culture requirements for in vitro development of human preimplantation embryos have not been fully defined. Helper cells in coculture would pave the way for repro-ducible embryo culture system of in vitro fertilization-embryo transfer(IVF-ET) in human. The purpose of this study is to evaluate the influence of BRL cells in coculture on human embryo development in vitro. Supernumerary 2-8 cell stage embryos from IVF-ET patients were used in this experiment. The embryos were assigned to two treatments, one for conventional embryo culture in 2 ml of Ham's F10 + 15% huamn serum(control), and the other for the coculture trial. Monlayer for the coculture of embryos was prepared by plating 1X 10(5) viable BRL cells per well in 4-well tissue culture plate 48 hours prior to the onset of coculture. In twenty four hours after plating, all wells were washed out and 0.5 ml of the medium was placed into the well and then preincubated. Embryos were scored according to embryo quality, assigned to each treatment and further cultured for 5 days. A total of 63 embryos from 10 patients were randomized(23 controls, 40 coculure). With grade I embryos, higher percentage of embryos in coculture group developed to blastocyst stage(61.3%) than in control group(30.7%, p < 0.05). With grade II and III embryos, no differences in the rates of development to morula and blastocyst sta-ge were found between control and coculture groups. The overall rates of development to morula and blastocyst stage were 65.2% and 21.7%, 77.5% and 50.0% for control and coculture, respectively. Differences in the development to blastocyst stage were found between control and coculture groups(p < 0.05). The data indicate that BRL cell coculture improves human embryo development to balstocyst stage in vitro.


Subject(s)
Animals , Female , Humans , Pregnancy , Rats , Blastocyst , Buffaloes , Coculture Techniques , Embryonic Development , Embryonic Structures , Morula , T-Lymphocytes, Helper-Inducer
15.
Journal of Korean Medical Science ; : 53-59, 1993.
Article in English | WPRIM | ID: wpr-222769

ABSTRACT

This study was performed to investigate the action of potassium channel openers on the mechanical activity of detrusor muscle isolated from rats. Detrusor muscle strips, 15 mm in length, were myographied isometrically in an isolated organ bath. P 1060, RP 49356 and BRL 38277, potassium channel activators, reduced the basal tone and diminished the phasic activity of detrusor concentration-dependently. P 1060, RP 49356 and BRL 38227 suppressed the maximal responses to bethanechol and shifted the concentration-response curves of bethanechol-induced contraction to the right. RP 49356 and BRL 38227 reduced the contraction by low (20 mM) concentration of potassium. P 1060, however, diminished the high (80 mM) and low (20 mM) concentration of potassium-induced contraction. Glibenclamide, an inhibitor of ATP-dependent potassium channel, antagonized the suppressive action of P 1060, RP 49356 and BRL 38227 on the basal tone. Apamin or procaine did not antagonize it significantly. Based on these results, it is suggested that the relaxation of detrusor muscle strip caused by P 1060, RP 49356 and BRL 38227 may predominantly involve opening of the same potassium channel, i.e., the ATP-dependent potassium channel.


Subject(s)
Animals , Rats , Benzopyrans/pharmacology , Cromakalim , Guanidines/pharmacology , Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Picolines/pharmacology , Potassium Channels/drug effects , Pyrans/pharmacology , Pyrroles/pharmacology , Rats, Sprague-Dawley , Urinary Bladder/drug effects
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