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1.
Zhen Ci Yan Jiu ; 49(4): 398-402, 2024 Apr 25.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-38649208

RESUMO

OBJECTIVES: To compare the clinical effect of combined therapy of acupotomy and electroacupuncture (EA) with the simple application of EA on knee osteoarthritis (KOA), and their influence on knee function. METHODS: Sixty-eight KOA patients were randomly divided into 2 groups, an acupotomy group and an EA group. In the acupotomy group, the combined therapy of acupotomy and EA was adopted. In the EA group, EA was simply used, delivered once every two days, 3 treatments a week;and the duration of treatment was 4 weeks. In the acupotomy group, besides the treatment as the EA group, acupotomy was combined once weekly, and the duration of treatment was 4 weeks. Separately, before and after treatment, and in 4 and 12 weeks after treatment completion (1-month and 3-month follow-up), the results of the timed up and go test (TUG), the 9-step stair climb test (9-SCT) and the knee function (Western Ontario and McMaster University osteoarthritis index visualization scale [WOMAC]) were measured in the two groups. RESULTS: By the intention-to-treat analysis, the results of TUG, 9-SCT and WOMAC scores were reduced after treatment and in 1-month and 3-month follow-up when compared with those before treatment in the patients of the two groups (P<0.05). Compared with the EA group at the same time point, TUG results were decreased after treatment and in 1-month follow-up, and WOMAC score was reduced after treatment in the acupotomy group. WOMAC score in 1-month follow-up was reduced when compared with that before treatment within the acupotomy group (P<0.05). CONCLUSIONS: Either the simple application of EA or the combined therapy of acupotomy and EA can improve knee function, but the combined therapy obviously increases the walking speed and relieves the symptoms such as joint pain and morning stiffness. The treatment with acupotomy and EA is safe and effective on KOA and the long-term effect is satisfactory.


Assuntos
Terapia por Acupuntura , Eletroacupuntura , Osteoartrite do Joelho , Humanos , Osteoartrite do Joelho/terapia , Osteoartrite do Joelho/fisiopatologia , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Resultado do Tratamento , Terapia Combinada , Articulação do Joelho/fisiopatologia , Pontos de Acupuntura
2.
Zhongguo Zhen Jiu ; 40(4): 379-83, 2020 Apr 12.
Artigo em Chinês | MEDLINE | ID: mdl-32275366

RESUMO

OBJECTIVE: To explore the therapeutic effect and partial mechanism of electroacupuncture (EA) for patients with insulin resistance (IR) polycystic ovary syndrome (PCOS). METHODS: Seventy patients with IR-PCOS were randomly divided into an EA group (36 cases, 5 cases dropped off) and a medication group (34 cases, 4 cases dropped off). The patients in the medication group were treated with oral administration of metformin hydrochloride, 500 mg each time, twice a day. The patients in the EA group were treated with EA (continuous wave, 2 Hz of frequency) at Zusanli (ST 36), Zhongwan (CV 12), Qihai (CV 6), Yishu (EX-B 3), Shenshu (BL 23), Pishu (BL 20), Ciliao (BL 32) for 30 min, three times a week. One menstrual cycle or 4 weeks were taken as a course of treatment, and 3 continuous courses were given. The follow-up was 3 months. The lipid metabolism indexes of triacylglycerol (TG), total cholesterol (TC), high-density lipoprotein (HDL) and low-density lipoprotein (LDL), homeostasis model assessment-insulin resistance index (HOMA-IR) and testosterone (T) in serum were compared before and after treatment, and the clinical effects of the two groups were evaluated during the follow-up. RESULTS: The total effective rate was 67.7% (21/31) in the EA group and 60.0% (18/30) in the medication group, with no significant difference between the two groups (P>0.05). After treatment, the levels of serum T, HOMA-IR, LDL, TG and TC were decreased significantly in the two groups (P<0.01, P<0.05), and HDL was increased significantly (P<0.01); the levels of TC in the EA group after treatment was lower than that in the medication group (P<0.05). CONCLUSION: EA may adjust some dyslipidemia in patients to correct IR and improve endocrine disorder of PCOS, which had superior/similar effects to metformin.


Assuntos
Eletroacupuntura , Resistência à Insulina , Síndrome do Ovário Policístico/terapia , Pontos de Acupuntura , Feminino , Humanos
3.
Toxins (Basel) ; 11(11)2019 11 14.
Artigo em Inglês | MEDLINE | ID: mdl-31739564

RESUMO

Deoxynivalenol (DON) is highly toxic to animals and humans, but pigs are most sensitive to it. The porcine mucosal injury related mechanism of DON is not yet fully clarified. Here, we investigated DON-induced injury in the intestinal tissues of piglet. Thirty weanling piglets [(Duroc × Landrace) × Yorkshire] were randomly divided into three groups according to single factor experimental design (10 piglets each group). Piglets were fed a basal diet in the control group, while low and high dose groups were fed a DON diet (1300 and 2200 µg/kg, respectively) for 60 days. Scanning electron microscopy results indicated that the ultrastructure of intestinal epithelial cells in the DON-treated group was damaged. The distribution and optical density (OD) values of zonula occludens 1 (ZO-1) protein in the intestinal tissues of DON-treated groups were decreased. At higher DON dosage, interleukin (IL)-1ß, IL-6, and tumor necrosis factor-α mRNA levels were elevated in the intestinal tissues. The mRNA and protein levels of NF-κB p65, IκB-α, IKKα/ß, iNOS, and COX-2 in the small intestinal mucosa were abnormally altered with an increase in DON concentration. These results indicate that DON can persuade intestinal damage and inflammatory responses in piglets via the nuclear factor-κB signaling pathway.


Assuntos
Inflamação/induzido quimicamente , Intestinos/efeitos dos fármacos , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tricotecenos/farmacologia , Animais , Células Epiteliais/metabolismo , Intestinos/patologia , Suínos
4.
Oncol Lett ; 18(3): 2771-2776, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31452755

RESUMO

Cervical cancer is one of the leading causes of cancer-associated mortality among females; however, the underlying molecular mechanisms of its carcinogenesis remain largely unclear. Previous comprehensive genomic studies have revealed prevalent estrogen receptor 1 (ESR1) mutations in breast cancer, which are rare in certain other types of cancer. To the best of our knowledge, it is unknown whether ESR1 mutations also exist in cervical cancer. Considering the evidence that cervical cancer shares certain genetic aberrations with breast cancer, and that the progression of both breast and cervical cancers can be affected by estrogen, it is possible that cervical cancer may also harbor ESR1 mutations. In the present study, a total of 260 Chinese cervical cancer samples with distinct subtypes were tested for the presence of ESR1 mutations. A total of three heterozygous missense ESR1 mutations, p.K303R (c.908A>G), p.T311M (c.932C>T) and p.Y537C (c.1610A>G), were identified in 3/207 (1.4%) cervical squamous cell carcinoma samples, which were absent in 27 adenosquamous carcinomas and 26 adenocarcinomas samples. Of the three individuals with an ESR1mutation, 1 patient was also diagnosed with ovarian endometriosis and the other 2 patients were diagnosed with a uterine fibroid. A bioinformatics analysis suggested that these ESR1 mutations may be pathogenic by promoting the development of cervical cancer. Furthermore, a previous comprehensive study confirmed that individuals with cervical squamous cell carcinoma possessed ESR1 mutations. These combined studies indicate that ESR1 mutations may participate in the carcinogenesis of cervical squamous cell carcinoma, albeit at a low frequency. In conclusion, the present study identified three potentially pathogenic ESR1 mutations in Chinese cervical squamous cell carcinoma samples, but not in other subtypes.

5.
Medicine (Baltimore) ; 95(30): e4297, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27472703

RESUMO

BACKGROUND: Wnt and transforming growth factor-ß (TGF-ß) signaling pathways are known to be involved in the pathogenesis of androgenetic alopecia (AGA). However, the way that Wnt and TGF-ß signaling is altered in patients with AGA and whether there exists a crosstalk between them in pathogenetic process of AGA remain unclear. OBJECTIVES: To investigate the expression of Wnt and TGF-ß signaling and the crosstalk between these 2 signaling pathways in AGA. METHODS: Fifteen male patients with AGA were recruited for our research. Fifteen scalp specimens of the balding were collected from frontal areas, and 9 nonbalding were collected from occipital areas. We analyzed the expression and activation of downstream Wnt and TGF-ß signaling molecules in both balding and nonbalding hair follicles isolated from scalp specimens. Furthermore, we evaluated the activation of Wnt and TGF-ß signaling after either of them was blocked with the inhibitor in balding and nonbalding dermal papilla (DP) cells. RESULTS: Compared with the nonbalding counterparts, the mRNA level of Wnt10a and LEF1 was decreased. But TßRI and TßRII, and the protein expression of TGF-ß1 was elevated in balding hair follicles. To investigate the crosstalk between Wnt and TGF-ß signaling, we used SB431542 to inhibit the TGF-ß signaling in balding DP cells and found that SB431542 significantly attenuated the phosphorylation of Smad2 and Akt. However, the mRNA level of Wnt10a, LEF1, and the nuclear translocation of ß-catenin was increased. On the other hand, we suppressed the Wnt signaling by XAV939 in nonbalding DP cells, which displayed that the level of ß-catenin and LEF1 was significantly inhibited; however, the level of active TGF-ß1 and the phosphorylation of Smad2 and Akt were up-regulated. CONCLUSIONS: These data indicate that crosstalk between Wnt/ß-catenin and TGF-ß signaling pathways may exist as one of the important mechanisms contributing to AGA.


Assuntos
Alopecia/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Via de Sinalização Wnt/fisiologia , Adulto , Western Blotting , Ensaio de Imunoadsorção Enzimática , Imunofluorescência , Humanos , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , RNA Mensageiro/fisiologia , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Transdução de Sinais
6.
Pharm Res ; 26(2): 459-68, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19082692

RESUMO

PURPOSE: Gaboxadol, a selective extrasynaptic agonist of the delta-containing gamma-aminobutyric acid type A (GABAA) receptor, is excreted in humans into the urine as parent drug and glucuronide conjugate. The goal of this study was to identify the UDP-Glucuronosyltransferase (UGT) enzymes and the transporters involved in the metabolism and active renal secretion of gaboxadol and its metabolite in humans.Methods. The structure of the glucuronide conjugate of gaboxadol in human urine was identified by LC/MS/MS. Human recombinant UGT isoforms were used to identify the enzymes responsible for the glucuronidation of gaboxadol. Transport of gaboxadol and its glucuronide was evaluated using cell lines and membrane vesicles expressing human organic anion transporters hOAT1 and hOAT3, organic cation transporter hOCT2, and the multidrug resistance proteins MRP2 and MRP4.Results. Our study indicated that the gaboxadol-O-glucuronide was the major metabolite excreted in human urine. UGT1A9, and to a lesser extent UGT1A6, UGT1A7 and UGT1A8, catalyzed the O-glucuronidation of gaboxadol in vitro. Gaboxadol was transported by hOAT1, but not by hOCT2, hOAT3, MRP2, and MRP4. Gaboxadol-O-glucuronide was transported by MRP4, but not MRP2.Conlusion. Gaboxadol could be taken up into the kidney by hOAT1 followed by glucuronidation and efflux of the conjugate into urine via MRP4.


Assuntos
Agonistas GABAérgicos/farmacocinética , Glucuronídeos/metabolismo , Glucuronosiltransferase/metabolismo , Isoxazóis/farmacocinética , Rim/enzimologia , Fígado/enzimologia , Proteínas de Membrana Transportadoras/metabolismo , Administração Oral , Animais , Biotransformação , Células CHO , Cromatografia Líquida , Cricetinae , Cricetulus , Agonistas GABAérgicos/administração & dosagem , Agonistas GABAérgicos/urina , Glucuronosiltransferase/genética , Humanos , Isoenzimas , Isoxazóis/administração & dosagem , Isoxazóis/urina , Proteínas de Membrana Transportadoras/genética , Microssomos Hepáticos/enzimologia , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Proteína 1 Transportadora de Ânions Orgânicos/metabolismo , Proteínas Recombinantes/metabolismo , Espectrometria de Massas em Tandem , Transfecção , UDP-Glucuronosiltransferase 1A
7.
Zhong Xi Yi Jie He Xue Bao ; 6(11): 1164-9, 2008 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-18990343

RESUMO

OBJECTIVE: To investigate the protective effects of Tangxinping Capsule, a compound traditional Chinese herbal medicine, on diabetic cardiomyopathy in rats. METHODS: The model of diabetes mellitus was induced by streptozotocin (STZ) injection in rats. And the rats with diabetes mellitus were randomly divided into untreated group, metformin group, captopril group, and low-, medium- and high-dose Tangxinping group; the other ten normal rats were used as normal controls. After eight-week treatment, all rats were sacrificed to detect angiotensin II (Ang II) protein content and angiotensin II type 1 receptor (AT1R) mRNA expression in myocardial tissues by radioimmunoassay and reverse transcription polymerase chain reaction (RT-PCR) respectively. The ultrastructural change in myocardial tissues was detected by transmission electron microscopy. RESULTS: The results of radioimmunoassay and RT-PCR showed that the content of Ang II protein and the expression of AT1R mRNA in myocardial tissue of the untreated group was significantly increased and more than those in normal control (P<0.05, P<0.01). Only the content of Ang II and expression of AT1R mRNA in high-dose Tangxinping group and captopril group were significantly lower than those in the untreated group (P<0.05, P<0.01). The transmission electron microscopy showed that volume of mitochondrion in myocardial tissue in the untreated group was bigger than that in normal control group. Also the volume of mitochondrion was improved in 5 treated groups, but had no significant difference when compared with the untreated group. CONCLUSION: Tangxinping may adjust the disorder of renin-angiotensin system to protect myocardial tissue in rats with cardiomyopathy due to diabetes.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Medicamentos de Ervas Chinesas/farmacologia , Miocárdio/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Angiotensina II/metabolismo , Animais , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/patologia , Medicamentos de Ervas Chinesas/uso terapêutico , Masculino , Miocárdio/ultraestrutura , RNA Mensageiro/genética , Ratos , Ratos Wistar , Receptor Tipo 1 de Angiotensina/genética
8.
Mol Pharmacol ; 74(2): 309-11, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18492796

RESUMO

Several members of the organic anion transporting polypeptide (OATP/Oatp) family of uptake transporters are expressed in the hepatocyte sinusoidal membrane in humans and preclinical species. The mouse liver specific Oatp is Oatp1b2, and the human homologs most closely related are OATP1B1 and 1B3. The substrate specificity of these transporters is broad, and the widely accepted view is that they play an important role in drug disposition. However, direct evidence that OATP/Oatps are important for drug disposition in vivo has been lacking thus far. In this issue of Molecular Pharmacology, Zaher et al. (p. 320), along with Lu et al. (Toxicol Sci 103: 35-45, 2008) , report on the characterization of mice with a targeted disruption of the organic anion transporting polypeptide Oatp1b2. The Oatp1b2(-/-) mice were viable and fertile and did not demonstrate obvious phenotypic abnormalities. Zaher et al. performed a pharmacokinetic analysis with the human OATP1B1 and -1B3 substrates rifampicin and pravastatin and demonstrated a reduced liver-to-plasma ratio for these drugs in knockout compared with control mice, providing strong evidence that Oatp1b2 played an important role in the disposition of these drugs. Lu et al. found that the Oatp1b2(-/-) mice were completely resistant to hepatoxicity induced by phalloidin and microcystin-LR. Taken together, these data illustrate that Oatp1b2(-/-) mice are an important new model to investigate the role of this transporter in drug disposition and hepatotoxicity.


Assuntos
Fígado/metabolismo , Transportadores de Ânions Orgânicos Sódio-Independentes/fisiologia , Preparações Farmacêuticas/metabolismo , Animais , Transporte Biológico/fisiologia , Humanos , Fígado/efeitos dos fármacos , Transportador 1 de Ânion Orgânico Específico do Fígado , Camundongos , Preparações Farmacêuticas/administração & dosagem , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/fisiologia
9.
J Pharmacol Exp Ther ; 321(2): 673-83, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17314201

RESUMO

Sitagliptin, a selective dipeptidyl peptidase 4 inhibitor recently approved for the treatment of type 2 diabetes, is excreted into the urine via active tubular secretion and glomerular filtration in humans. In this report, we demonstrate that sitagliptin is transported by human organic anion transporter hOAT3 (Km=162 microM), organic anion transporting polypeptide OATP4C1, and multidrug resistance (MDR) P-glycoprotein (Pgp), but not by human organic cation transporter 2 hOCT2, hOAT1, oligopeptide transporter hPEPT1, OATP2B1, and the multidrug resistance proteins MRP2 and MRP4. Our studies suggested that hOAT3, OATP4C1, and MDR1 Pgp might play a role in transporting sitagliptin into and out of renal proximal tubule cells, respectively. Sitagliptin did not inhibit hOAT1-mediated cidofovir uptake, but it showed weak inhibition of hOAT3-mediated cimetidine uptake (IC50=160 microM). hOAT3-mediated sitagliptin uptake was inhibited by probenecid, ibuprofen, furosemide, fenofibric acid, quinapril, indapamide, and cimetidine with IC50 values of 5.6, 3.7, 1.7, 2.2, 6.2, 11, and 79 microM, respectively. Sitagliptin did not inhibit Pgp-mediated transport of digoxin, verapamil, ritonavir, quinidine, and vinblastine. Cyclosporine A significantly inhibited Pgp-mediated transport of sitagliptin (IC50=1 microM). Our data indicate that sitagliptin is unlikely to be a perpetrator of drug-drug interactions with Pgp, hOAT1, or hOAT3 substrates at clinically relevant concentrations. Renal secretion of sitagliptin could be inhibited if coadministered with OAT3 inhibitors such as probenecid. However, the magnitude of interactions should be low, and the effects may not be clinically meaningful, due to the high safety margin of sitagliptin.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Inibidores de Adenosina Desaminase , Inibidores da Dipeptidil Peptidase IV , Inibidores Enzimáticos/metabolismo , Glicoproteínas/antagonistas & inibidores , Transportadores de Ânions Orgânicos Sódio-Independentes/fisiologia , Transportadores de Ânions Orgânicos/fisiologia , Pirazinas/metabolismo , Triazóis/metabolismo , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Animais , Transporte Biológico , Células CHO , Cricetinae , Cricetulus , Dipeptidil Peptidase 4 , Humanos , Masculino , Proteínas de Membrana Transportadoras/fisiologia , Camundongos , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/fisiologia , Fosfato de Sitagliptina
10.
J Pharmacol Exp Ther ; 317(2): 579-89, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16421286

RESUMO

The multidrug resistance protein Mrp2 is an ATP-binding cassette (ABC) transporter mainly expressed in liver, kidney, and intestine. One of the physiological roles of Mrp2 is to transport bilirubin glucuronides from the liver into the bile. Current in vivo models to study Mrp2 are the transporter-deficient and Eisai hyperbilirubinemic rat strains. Previous reports showed hyperbilirubinemia and induction of Mrp3 in the hepatocyte sinusoidal membrane in the mutant rats. In addition, differences in liver cytochrome P450 and UGT1a levels between wild-type and mutant rats were detected. To study whether these compensatory mechanisms were specific to rats, we characterized Mrp2(-/-) mice. Functional absence of Mrp2 in the knockout mice was demonstrated by showing increased levels of bilirubin and bilirubin glucuronides in serum and urine, a reduction in biliary excretion of bilirubin glucuronides and total glutathione, and a reduction in the biliary excretion of the Mrp2 substrate dibromosulfophthalein. To identify possible compensatory mechanisms in Mrp2(-/-) mice, the expression levels of 98 phase I, phase II, and transporter genes were compared in liver, kidney, and intestine of male and female Mrp2(-/-) and control mice. Unlike in Mrp2 mutant rats, no induction of Mrp3 in Mrp2(-/-) mice was detected. However, Mrp4 mRNA and protein in liver and kidney were increased approximately 6- and 2-fold, respectively. Phenotypic analysis of major cytochrome P450-mediated activities in liver microsomes did not show differences between wild-type and Mrp2(-/-) mice. In conclusion, Mrp2(-/-) mice are a new valuable tool to study the role of Mrp2 in drug disposition.


Assuntos
Bilirrubina/análogos & derivados , Expressão Gênica , Proteínas de Membrana Transportadoras/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Animais , Bile/metabolismo , Bilirrubina/sangue , Bilirrubina/urina , Sistema Enzimático do Citocromo P-450/metabolismo , Feminino , Glutationa/metabolismo , Mucosa Intestinal/metabolismo , Rim/metabolismo , Fígado/metabolismo , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Knockout , Proteína 2 Associada à Farmacorresistência Múltipla , Sulfobromoftaleína/farmacocinética
11.
J Pharmacol Exp Ther ; 309(1): 156-64, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-14722317

RESUMO

Ethinylestradiol (EE) is one of the key constituents of oral contraceptives. Major metabolites of EE in humans are the glucuronide and sulfate conjugates, EE-3-O-glucuronide (EE-G) and EE-3-O-sulfate (EE-S). In the present study, transport of EE-G and EE-S by the human multidrug resistance proteins MRP1, MRP2, and MRP3 was investigated using inside-out membrane vesicles, isolated from Sf9 cells expressing human MRP1, MRP2, or MRP3. Vesicular uptake studies showed that EE-G was not a substrate for MRP1, whereas an ATP-dependent and saturable transport of [(3)H]EE-G was observed in MRP2 (K(m) of 35.1 +/- 3.5 microM) and MRP3 (K(m) of 9.2 +/- 2.3 microM) containing vesicles. EE-S was not transported by either MRP1, MRP2, or MRP3. However, low concentrations of EE-S stimulated MRP2-mediated uptake of ethacrynic acid glutathione. EE-S also stimulated MRP2 and MRP3-mediated uptake of 17beta-estradiol-17beta-D-glucuronide. Interestingly, EE-S stimulated strongly MRP2- and MRP3-mediated uptake of EE-G by increasing its apparent transport affinity, whereas no reciprocal stimulation of EE-S uptake by EE-G was observed. These data indicate that EE-S allosterically stimulates MRP2- and MRP3-mediated transport of EE-G and is not cotransported with EE-G. Our studies demonstrate specific active transport of a pharmacologically relevant drug conjugate by human MRP2 and MRP3, involving complex interactions with other organic anions. We also suggest that caution needs to be taken when using only competition studies as screening tools to identify substrates or inhibitors of MRP-mediated transport.


Assuntos
Estradiol/análogos & derivados , Etinilestradiol/análogos & derivados , Etinilestradiol/farmacocinética , Proteínas de Membrana Transportadoras/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Animais , Transporte Biológico , Linhagem Celular , Membrana Celular/metabolismo , Interações Medicamentosas , Estradiol/farmacologia , Insetos/citologia , Proteína 2 Associada à Farmacorresistência Múltipla , Trítio
12.
J Biol Chem ; 278(28): 25348-56, 2003 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-12732646

RESUMO

Valacyclovir is the 5'-valyl ester prodrug of acyclovir, an effective anti-herpetic drug. Systemic availability of acyclovir in humans is three to five times higher when administered orally as the prodrug. The increased bioavailability of valacyclovir is attributed to carrier-mediated intestinal absorption, via the hPEPT1 peptide transporter, followed by the rapid and complete conversion to acyclovir. The one or more human enzymes responsible for in vivo activation of the prodrug to the active drug and its conversion sites, however, have not been identified. In this report, we describe the purification, identification, and characterization of a human enzyme that activates valacyclovir to acyclovir. A protein with significant hydrolytic activity toward valacyclovir, the 5'-glycyl ester of acyclovir, and the 5'-valyl ester of zidovudine (AZT), was purified from Caco-2 cells derived from human intestine. Using a non-redundant data base search, the N-terminal 19-amino acid sequence of the purified 27-kDa, basic protein revealed a perfect match within the N terminus of a serine hydrolase, Biphenyl hydrolase-like (BPHL, gi:4757862) protein, previously cloned from human breast carcinoma. Recombinant BPHL exhibited significant hydrolytic activity for both valacyclovir and valganciclovir with specificity constants (kcat/Km), 420 and 53.2 mm-1.s-1, respectively. We conclude that BPHL may be an important enzyme activating valacyclovir and valganciclovir in humans and an important new target for prodrug design.


Assuntos
Aciclovir/análogos & derivados , Aciclovir/química , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/farmacologia , Hidrolases/química , Valina/análogos & derivados , Valina/química , Sequência de Aminoácidos , Western Blotting , Linhagem Celular , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Mucosa Intestinal/metabolismo , Cinética , Modelos Químicos , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Homologia de Sequência de Aminoácidos , Valaciclovir
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