Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 229
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38522903

RESUMO

BACKGROUND: Perfluorooctanoic acid (PFOA) is one of the major per- and polyfluoroalkyl substances. The role of ATP-binding cassette (ABC) transporters in PFOA toxicokinetics is unknown. METHODS: In this study, two ABC transporters, ABCB1 and ABCB4, were examined in mice with single intravenous PFOA administration (3.13 µmol/kg). To identify candidate renal PFOA transporters, we used a microarray approach to evaluate changes in gene expression of various kidney transporters in Abcb4 null mice. RESULTS: Biliary PFOA concentrations were lower in Abcb4 null mice (mean ± standard deviation: 0.25 ± 0.12 µg/mL) than in wild-type mice (0.87 ± 0.02 µg/mL). Immunohistochemically, ABCB4 expression was confirmed at the apical region of hepatocytes. However, renal clearance of PFOA was higher in Abcb4 null mice than in wild-type mice. Among 642 solute carrier and ABC transporters, 5 transporters showed significant differences in expression between wild-type and Abcb4 null mice. These candidates included two major xenobiotic transporters, multidrug resistance 1 (Abcb1) and organic anion transporter 3 (Slc22a8). Abcb1 mRNA levels were higher in Abcb4 null mice than in wild-type mice in kidney. In Abcb4 null mice, Abcb1b expression was enhanced in proximal tubules immunohistochemically, while that of Slc22a8 was not. Finally, in Abcb1a/b null mice, there was a significant decrease in the renal clearance of PFOA (0.69 ± 0.21 vs 1.1 mL ± 0.37/72 h in wild-type mice). A homology search of ABCB1 showed that several amino acids are mutated in humans compared with those in rodents and monkeys. CONCLUSIONS: These findings suggest that, in the mouse, Abcb4 and Abcb1 are excretory transporters of PFOA into bile and urine, respectively.


Assuntos
Caprilatos , Fluorocarbonos , Eliminação Hepatobiliar , Humanos , Camundongos , Animais , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Fluorocarbonos/toxicidade , Fluorocarbonos/metabolismo , Rim , Subfamília B de Transportador de Cassetes de Ligação de ATP/genética , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo
2.
Biol Pharm Bull ; 47(2): 427-433, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38369341

RESUMO

It has recently been reported that cholangiocyte organoids can be established from primary human hepatocytes. The purpose of this study was to culture the organoids in monolayers on inserts to investigate the biliary excretory capacity of drugs. Cholangiocyte organoids prepared from hepatocytes had significantly higher mRNA expression of CK19, a bile duct epithelial marker, compared to hepatocytes. The organoids also expressed mRNA for efflux transporters involved in biliary excretion of drugs, P-glycoprotein (P-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP). The subcellular localization of each protein was observed. These results suggest that the membrane-cultured cholangiocyte organoids are oriented with the upper side being the apical membrane side (A side, bile duct lumen side) and the lower side being the basolateral membrane side (B side, hepatocyte side), and that each efflux transporter is localized to the apical membrane side. Transport studies showed that the permeation rate from the B side to the A side was faster than from the A side to the B side for the substrates of each efflux transporter, but this directionality disappeared in the presence of inhibitor of each transporter. In conclusion, the cholangiocyte organoid monolayer system has the potential to quantitatively evaluate the biliary excretion of drugs. The results of the present study represent an unprecedented system using human cholangiocyte organoids, which may be useful as a screening model to directly quantify the contribution of biliary excretion to the clearance of drugs.


Assuntos
Eliminação Hepatobiliar , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Humanos , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Hepatócitos/metabolismo , RNA Mensageiro/metabolismo
3.
J Vet Med Sci ; 85(10): 1099-1105, 2023 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-37635088

RESUMO

The aim of this study was to measure the concentrations of enrofloxacin (ERFX) and other fluoroquinolones; orbifloxacin (OBFX), marbofloxacin (MBFX), and ofloxacin (OFLX) in the plasma and bile of rabbits after a single intravenous (IV) injection. Twenty male rabbits were divided into four groups and given each drug by IV injection into the ear vein at a dose of 5.0 mg/kg BW. The concentration of ERFX, ciprofloxacin (CPFX), OBFX, MBFX and OFLX in plasma and bile were determined by HPLC. CPFX, metabolite of ERFX, was also measured by HPLC in plasma and bile of rabbits receiving ERFX. Several pharmacokinetic parameters in plasma were calculated and biliary clearance (CLbile) was calculated from extent of biliary excretion and accumulation of AUC of each drug. After IV injection, elimination half-life (t1/2ß) was 4.13, 3.68, 6.60, 5.14 hr; volume of distribution at a steady state (Vdss) was 1.24, 0.503, 0.771, 1.02 L/kg; and total body clearance (CLtot) was 1.05, 0.418, 0.271, 0.453 L/kg/hr, respectively. The values for CLbile for ERFX, OBFX, MBFX, and OFLX were 0.0048, 0.0050, 0.0057, and 0.0094 L/kg/hr, respectively. These values represent 0.48%, 1.2%, 2.1%, and 2.3% of the total body clearance (CLtot) of each drug, respectively. The biliary clearance of CPFX was also measured and found to be 0.0199 L/kg/hr with ERFX administration. The results showed that ERFX, OBFX, MBFX, and OFLX were not excreted into the bile to a significant extent, making them safe drugs to use in rabbits.


Assuntos
Fluoroquinolonas , Eliminação Hepatobiliar , Coelhos , Masculino , Animais , Injeções Intravenosas/veterinária , Fluoroquinolonas/farmacocinética , Enrofloxacina , Área Sob a Curva , Meia-Vida
4.
Commun Biol ; 6(1): 866, 2023 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-37608051

RESUMO

Biliary excretion is a major drug elimination pathway that affects their efficacy and safety. The currently available in vitro sandwich-cultured hepatocyte method is cumbersome because drugs accumulate in the closed bile canalicular lumen formed between hepatocytes and their amounts cannot be mealsured directly. This study proposes a hepatocyte culture model for the rapid evaluation of drug biliary excretion using permeation assays. When hepatocytes are cultured on a permeable support coated with the cell adhesion protein claudins, an open-form bile canalicular lumen is formed at the surface of the permeable support. Upon application to the basolateral (blood) side, drugs appear on the bile canalicular side. The biliary excretion clearance of several drugs, as estimated from the obtained permeabilities, correlates well with the reported in vivo biliary excretion clearance in humans. Thus, the established model is useful for applications in the efficient evaluation of biliary excretion during drug discovery and development.


Assuntos
Canalículos Biliares , Eliminação Hepatobiliar , Humanos , Vias de Eliminação de Fármacos , Bioensaio , Hepatócitos
5.
Pharm Res ; 40(7): 1723-1734, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37258948

RESUMO

PURPOSE: Colistin is an antibiotic which is increasingly used as a last-resort therapy in critically-ill patients with multidrug resistant Gram-negative infections. The purpose of this study was to evaluate the mechanisms underlying colistin's pharmacokinetic (PK) behavior and to characterize its hepatic metabolism. METHODS: In vitro incubations were performed using colistin sulfate with rat liver microsomes (RLM) and with rat and human hepatocytes (RH and HH) in suspension. The uptake of colistin in RH/HH and thefraction of unbound colistin in HH (fu,hep) was determined. In vitro to in vivo extrapolation (IVIVE) was employed to predict the hepatic clearance (CLh) of colistin. RESULTS: Slow metabolism was detected in RH/HH, with intrinsic clearance (CLint) values of 9.34± 0.50 and 3.25 ± 0.27 mL/min/kg, respectively. Assuming the well-stirred model for hepatic drug elimination, the predicted rat CLh was 3.64± 0.22 mL/min/kg which could explain almost 70% of the reported non-renal in vivo clearance. The predicted human CLh was 91.5 ± 8.83 mL/min, which was within two-fold of the reported plasma clearance in healthy volunteers. When colistin was incubated together with the multidrug resistance-associated protein (MRP/Mrp) inhibitor benzbromarone, the intracellular accumulation of colistin in RH/HH increased significantly. CONCLUSION: These findings indicate the major role of hepatic metabolism in the non-renal clearance of colistin, while MRP/Mrp-mediated efflux is involved in the hepatic disposition of colistin. Our data provide detailed quantitative insights into the hereto unknown mechanisms responsible for non-renal elimination of colistin.


Assuntos
Colistina , Eliminação Hepatobiliar , Humanos , Ratos , Animais , Colistina/metabolismo , Fígado/metabolismo , Hepatócitos/metabolismo , Microssomos Hepáticos/metabolismo , Taxa de Depuração Metabólica
6.
Clin Pharmacol Ther ; 114(1): 137-147, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37042227

RESUMO

Realistic models predicting hepatobiliary processes in health and disease are lacking. We therefore aimed to develop a physiologically relevant human liver model consisting of normothermic machine perfusion (NMP) of explanted diseased human livers that can assess hepatic extraction, clearance, biliary excretion, and drug-drug interaction (DDI). Eleven livers were included in the study, seven with a cirrhotic and four with a noncirrhotic disease background. After explantation of the diseased liver, NMP was initiated. After 120 minutes of perfusion, a drug cocktail (rosuvastatin, digoxin, metformin, and furosemide; OATP1B1/1B3, P-gp, BCRP, and OCT1 model compounds) was administered to the portal vein and 120 minutes later, a second bolus of the drug cocktail was co-administered with perpetrator drugs to study relevant DDIs. The explanted livers showed good viability and functionality during 360 minutes of NMP. Hepatic extraction ratios close to in vivo reported values were measured. Hepatic clearance of rosuvastatin and digoxin showed to be the most affected by cirrhosis with an increase in maximum plasma concentration (Cmax ) of 11.50 and 2.89 times, respectively, compared with noncirrhotic livers. No major differences were observed for metformin and furosemide. Interaction of rosuvastatin or digoxin with perpetrator drugs were more pronounced in noncirrhotic livers compared with cirrhotic livers. Our results demonstrated that NMP of human diseased explanted livers is an excellent model to assess hepatic extraction, clearance, biliary excretion, and DDI. Gaining insight into pharmacokinetic profiles of OATP1B1/1B3, P-gp, BCRP, and OCT1 model compounds is a first step toward studying transporter functions in diseased livers.


Assuntos
Furosemida , Metformina , Humanos , Rosuvastatina Cálcica/farmacocinética , Furosemida/farmacocinética , Eliminação Hepatobiliar , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Fígado/metabolismo , Cirrose Hepática , Metformina/farmacocinética , Digoxina/farmacocinética , Interações Medicamentosas
7.
J Toxicol Sci ; 48(5): 251-261, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37121740

RESUMO

The biliary excretion of pharmaceutical and food-related compounds is an important factor for assessing pharmacokinetics and toxicities in humans, and a highly predictive in vitro method for human biliary excretion is required. We have developed a simple in vitro culture method for generating extended and functional bile canaliculi using cryopreserved human hepatocytes. We evaluated the uptake of compounds by hepatocytes and bile canaliculi, and the biliary excretion index (BEI) was calculated. After 21 days of culture, the presence of extended and functional bile canaliculi was confirmed by the uptake of two fluorescent substrates. Positive BEIs were observed for taurocholic acid-d4, rosuvastatin, pitavastatin, pravastatin, valsartan, olmesartan, and topotecan (reported biliary-excreted compounds in humans), but no difference in BEI was observed for salicylic acid (a nonbiliary-excreted compound). Furthermore, 8 of 21 food-related compounds with specific structures and reported biliary transporter involvement exhibited positive BEIs. The developed in vitro system was characterized by functional bile canaliculus-like structures, and it could be applied to the prediction of the biliary excretion of pharmaceutical and food-related compounds.


Assuntos
Canalículos Biliares , Eliminação Hepatobiliar , Humanos , Canalículos Biliares/metabolismo , Células Cultivadas , Hepatócitos , Preparações Farmacêuticas/metabolismo
8.
Gastroenterology ; 165(1): 187-200.e7, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36966941

RESUMO

BACKGROUND & AIMS: Excess copper causes hepatocyte death in hereditary Wilson's disease (WD). Current WD treatments by copper-binding chelators may gradually reduce copper overload; they fail, however, to bring hepatic copper close to normal physiological levels. Consequently, lifelong daily dose regimens are required to hinder disease progression. This may result in severe issues due to nonadherence or unwanted adverse drug reactions and also due to drug switching and ultimate treatment failures. This study comparatively tested bacteria-derived copper binding agents-methanobactins (MBs)-for efficient liver copper depletion in WD rats as well as their safety and effect duration. METHODS: Copper chelators were tested in vitro and in vivo in WD rats. Metabolic cage housing allowed the accurate assessment of animal copper balances and long-term experiments related to the determination of minimal treatment phases. RESULTS: We found that copper-binding ARBM101 (previously known as MB-SB2) depletes WD rat liver copper dose dependently via fecal excretion down to normal physiological levels within 8 days, superseding the need for continuous treatment. Consequently, we developed a new treatment consisting of repetitive cycles, each of ∼1 week of ARBM101 applications, followed by months of in-between treatment pauses to ensure a healthy long-term survival in WD rats. CONCLUSIONS: ARBM101 safely and efficiently depletes excess liver copper from WD rats, thus allowing for short treatment periods as well as prolonged in-between rest periods.


Assuntos
Degeneração Hepatolenticular , Ratos , Animais , Degeneração Hepatolenticular/tratamento farmacológico , Degeneração Hepatolenticular/metabolismo , Cobre , Eliminação Hepatobiliar , Fígado/metabolismo , Quelantes/farmacologia , Quelantes/uso terapêutico
9.
Drug Metab Dispos ; 51(5): 618-628, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36732075

RESUMO

Among the basic hepatic clearance models, the dispersion model (DM) is the most physiologically sound compared with the well-stirred model and the parallel tube model. However, its application in physiologically-based pharmacokinetic (PBPK) modeling has been limited due to computational complexities. The series compartment models (SCM) of hepatic elimination that treats the liver as a cascade of well-stirred compartments connected by hepatic blood flow exhibits some mathematical similarities to the DM but is easier to operate. This work assesses the quantitative correlation between the SCM and DM and demonstrates the operation of the SCM in PBPK with the published single-dose blood and liver concentration-time data of six flow-limited compounds. The predicted liver concentrations and the estimated intrinsic clearance (CLint ) and PBPK-operative tissue-to-plasma partition coefficient (Kp ) values were shown to depend on the number of liver sub-compartments (n) and hepatic enzyme zonation in the SCM. The CLint and Kp decreased with increasing n, with more remarkable differences for drugs with higher hepatic extraction ratios. Given the same total CLint , the SCM yields a higher Kp when the liver perivenous region exhibits a lower CLint as compared with a high CLint at this region. Overall, the SCM nicely approximates the DM in characterizing hepatic elimination and offers an alternative flexible approach as well as providing some insights regarding sequential drug concentrations in the liver. SIGNIFICANCE STATEMENT: The SCM nicely approximates the DM when applied in PBPK for characterizing hepatic elimination. The number of liver sub-compartments and hepatic enzyme zonation are influencing factors for the SCM resulting in model-dependent predictions of total/internal liver concentrations and estimates of CLint and the PBPK-operative Kp . Such model-dependency may have an impact when the SCM is used for in vitro-to-in vivo extrapolation (IVIVE) and may also be relevant for PK/PD/toxicological effects when it is the driving force for such responses.


Assuntos
Eliminação Hepatobiliar , Modelos Biológicos , Fígado/metabolismo
10.
Clin Transl Sci ; 16(1): 50-61, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36176049

RESUMO

Despite the liver being the primary site for clearance of xenobiotics utilizing a myriad of mechanisms ranging from cytochrome P450 enzyme pathways, glucuronidation, and biliary excretion, there is a dearth of information available as to how the severity of hepatic impairment (HI) can alter drug absorption and disposition (i.e., pharmacokinetics [PK]) as well as their efficacy and safety or pharmacodynamics (PD). In general, regulatory agencies recommend conducting PK studies in subjects with HI when hepatic metabolism/excretion accounts for more than 20% of drug elimination or if the drug has a narrow therapeutic range. In this tutorial, we provide an overview of the global regulatory landscape, clinical measures for hepatic function assessment, methods to stage HI severity, and consequently the impact on labeling. In addition, we provide an in-depth practical guidance for designing and conducting clinical trials for patients with HI and on the application of modeling and simulation strategies in lieu of dedicated trials for dosing recommendations in patients with HI.


Assuntos
Sistema Enzimático do Citocromo P-450 , Eliminação Hepatobiliar , Hepatopatias , Humanos , Sistema Enzimático do Citocromo P-450/metabolismo , Eliminação Hepatobiliar/fisiologia , Hepatopatias/tratamento farmacológico , Hepatopatias/metabolismo
11.
J Clin Endocrinol Metab ; 107(3): e980-e995, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-34718621

RESUMO

CONTEXT: Severe osteodystrophy is common in patients with liver dysfunction. Markers of bone metabolism may help in early diagnosis of osteodystrophy and in understanding underlying pathophysiological mechanisms. OBJECTIVE: To elucidate changes in bone metabolism associated with cirrhosis and to determine the route of elimination for the markers. METHODS: Case-control study at a public university hospital. Fifty-nine patients with cirrhosis (47 alcoholic and 12 nonalcoholic cirrhosis) and 20 controls were included. Participants underwent catheterization of the femoral artery, and the hepatic, renal, and femoral veins with collection of blood from all 4 sites. Regional arteriovenous differences in concentrations of bone metabolism markers were determined: procollagen of type I collagen propeptide (PINP), C-terminal cross-linking telopeptide of type I collagen (CTX), osteocalcin, tartrate-resistant acid phosphatase isoform 5b (TRAcP5b), osteoprotegerin (OPG), and sclerostin and correlated with degree of disease (Child-Pugh classification). RESULTS: PINP concentration was higher (median: 87.9 µg/L) in patients with cirrhosis than in controls (52.6 µg/L) (P = .001), while hepatic extraction was lower (4.3% vs 14.5%) (P < .001). Both CTX and TRAcP5b were higher in patients with cirrhosis (340 ng/L and 3.20 U/L) than in controls (215 ng/L and 1.60 U/L) (P < .001 and P < .0001). Hepatic sclerostin extraction was lower in patients with cirrhosis (14.6%) than in controls (28.7%) (P < .0001). In both groups OPG showed a hepatic release rate (production) of 6%. CONCLUSION: Patients with cirrhosis have increased bone resorption, but unaltered bone formation. Sclerostin is eliminated through the liver while OPG is produced in the liver. Bone markers may prove useful in evaluating bone turnover in patients with cirrhosis.


Assuntos
Doenças Ósseas Metabólicas/diagnóstico , Remodelação Óssea , Cirrose Hepática/complicações , Fígado/metabolismo , Osteoprotegerina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/sangue , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Idoso , Biomarcadores/sangue , Biomarcadores/metabolismo , Doenças Ósseas Metabólicas/sangue , Estudos de Casos e Controles , Feminino , Eliminação Hepatobiliar , Humanos , Fígado/patologia , Cirrose Hepática/sangue , Cirrose Hepática/metabolismo , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-Idade , Osteoprotegerina/sangue
12.
Clin Pharmacol Ther ; 111(2): 496-508, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34679189

RESUMO

Neonatal opioid withdrawal syndrome (NOWS) is a major public health concern whose incidence has paralleled the opioid epidemic in the United States. Sublingual buprenorphine is an emerging treatment for NOWS, but given concerns about long-term adverse effects of perinatal opioid exposure, precision dosing of buprenorphine is needed. Buprenorphine pharmacokinetics (PK) in newborns, however, is highly variable. To evaluate underlying sources of PK variability, a neonatal physiologically-based pharmacokinetic (PBPK) model of sublingual buprenorphine was developed using Simcyp (version 19.1). The PBPK model included metabolism by cytochrome P450 (CYP) 3A4, CYP2C8, UDP-glucuronosyltransferase (UGT) 1A1, UGT1A3, UGT2B7, and UGT2B17, with additional biliary excretion. Maturation of metabolizing enzymes was incorporated, and default CYP2C8 and UGT2B7 ontogeny profiles were updated according to recent literature. A biliary clearance developmental profile was outlined using clinical data from neonates receiving sublingual buprenorphine as NOWS treatment. Extensive PBPK model validation in adults demonstrated good predictability, with geometric mean (95% confidence interval (CI)) predicted/observed ratios (P/O ratios) of area under the curve from zero to infinity (AUC0-∞ ), peak concentration (Cmax ), and time to reach peak concentration (Tmax ) equaling 1.00 (0.74-1.33), 1.04 (0.84-1.29), and 0.95 (0.72-1.26), respectively. In neonates, the geometric mean (95% CI) P/O ratio of whole blood concentrations was 0.75 (95% CI 0.64-0.87). PBPK modeling and simulation demonstrated that variability in biliary clearance, sublingual absorption, and CYP3A4 abundance are likely important drivers of buprenorphine PK variability in neonates. The PBPK model could be used to guide development of improved buprenorphine starting dose regimens for the treatment of NOWS.


Assuntos
Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Buprenorfina/administração & dosagem , Modelos Biológicos , Síndrome de Abstinência Neonatal/tratamento farmacológico , Tratamento de Substituição de Opiáceos , Administração Intravenosa , Administração Sublingual , Adulto , Idoso , Analgésicos Opioides/farmacocinética , Biotransformação , Buprenorfina/efeitos adversos , Buprenorfina/farmacocinética , Criança , Pré-Escolar , Citocromo P-450 CYP3A/metabolismo , Cálculos da Dosagem de Medicamento , Feminino , Eliminação Hepatobiliar , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Síndrome de Abstinência Neonatal/sangue , Síndrome de Abstinência Neonatal/diagnóstico , Absorção pela Mucosa Oral , Resultado do Tratamento , Adulto Jovem
13.
Clin Nucl Med ; 47(1): 59-60, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34034319

RESUMO

ABSTRACT: Tri-alkoxysalicyl-1,4-diazepan-6-amine (TAoS-DAZA) ligands, radiolabelled with 68Ga, have been proposed as PET/CT agents for depiction and quantification of hepatobiliary function and evaluation of bile excretion. In the presented case, a patient with hepatocellulary carcinoma underwent PET/CT with the TAoS-derivate 68Ga-tri-methoxysalicyl-(TMoS)-DAZA to determine the patency of intrahepatic and extrahepatic bile ducts, in particular of a stent in the common bile duct. The PET/CT was performed without complications. Evaluation of bile excretion over time was possible. 68Ga-TAoS-DAZA PET/CT may be an option for dynamic imaging of the excretory hepatic function to visualize the biliary tree and to rule out cholestasis.


Assuntos
Sistema Biliar , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Ductos Biliares , Sistema Biliar/diagnóstico por imagem , Eliminação Hepatobiliar , Humanos , Fígado/diagnóstico por imagem , Fígado/metabolismo
14.
Pharm Res ; 38(12): 2035-2046, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34862570

RESUMO

PURPOSE: To estimate hepatobiliary clearances of rosuvastatin via simultaneously fitting to reported human positron emission tomography (PET) data in the liver and gallbladder. METHODS: A hepatobiliary model incorporating five intrinsic hepatobiliary clearances (active uptake clearance at the sinusoidal membrane, efflux clearance by passive diffusion through the sinusoidal membrane, influx clearance by passive diffusion through sinusoidal membrane, clearance of biliary excretion at the canalicular membrane, and intercompartment clearance from the intrahepatic bile duct to the gallbladder) and three compartments (liver, intrahepatic bile duct, and gallbladder) was developed to simultaneously fit rosuvastatin liver and gallbladder data from a representative subject reported by Billington et al. (1). Two liver blood supply input functions, arterial input function and dual input function (using peripheral venous as an alternative to portal vein), were assessed. Additionally, the predictive performance between the established model and four reported models trained with only systemic exposure data, was evaluated by comparing simulated liver and gallbladder profiles with observations. RESULTS: The established hepatobiliary model well captured the kinetic profiles of rosuvastatin in the liver and gallbladder during the PET scans. Application of dual input function led to a marked underestimation of liver concentrations at the initial stage after i.v. dosing which cannot be offset by altering model parameter values. The simulated hepatobiliary profiles from three of the reported models demonstrated substantial deviation from the observed data. CONCLUSIONS: The present study highlights the necessity of using hepatobiliary data to verify and improve the predictive performance of hepatic disposition of rosuvastatin.


Assuntos
Vesícula Biliar/metabolismo , Eliminação Hepatobiliar , Fígado/metabolismo , Rosuvastatina Cálcica/farmacocinética , Conjuntos de Dados como Assunto , Vesícula Biliar/diagnóstico por imagem , Humanos , Fígado/diagnóstico por imagem , Modelos Biológicos , Tomografia por Emissão de Pósitrons , Distribuição Tecidual
15.
Pharm Res ; 38(11): 1847-1862, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34773182

RESUMO

PURPOSE: Sulcardine sulfate (Sul) is a novel antiarrhythmic agent with promising pharmacological properties, which is currently being evaluated in several clinical trials as an oral formulation. To meet the medication needs of patients with acute conditions, the injection formulation of Sul has been developed. The objective of this study was to systemically investigate the pharmacokinetic profiles of Sul after intravenous infusion. METHODS: This research included the plasma protein binding and metabolic stability studies in vitro, plasma pharmacokinetics, biodistribution, excretion studies in animals, and the prediction of the clinical PK of Sul injection using a physiologically based pharmacokinetics (PBPK) model. RESULTS: The metabolic stability was similarly in dogs and humans but lower in rats. The plasma protein binding rates showed a concentration-dependent manner and species differences. The pharmacokinetic behavior after intravenous administration was linear in rats within the dose range of 30-90 mg/kg, but nonlinear in dogs within 30-60 mg/kg. Sul could be rapidly and widely distributed in multiple tissues after intravenous administration. About 12% of the parent compound were excreted via the urine and only a small fraction via bile and feces,and eight metabolites were found and identified in the rat excretion. The PBPK models were developed and simulated the observed PK date well in both rats and dogs. The PBPK model refined with human data predicted the PK characteristics of the first intravenous infusion of Sul in human. CONCLUSIONS: Our study systematically explored the pharmacokinetic characteristics of Sul and successfully developed the PBPK model to predict of its clinical PK.


Assuntos
Antiarrítmicos/farmacocinética , Modelos Biológicos , Ésteres do Ácido Sulfúrico/farmacocinética , Animais , Antiarrítmicos/administração & dosagem , Cães , Avaliação Pré-Clínica de Medicamentos , Feminino , Eliminação Hepatobiliar , Humanos , Infusões Intravenosas , Injeções Intravenosas , Eliminação Intestinal , Masculino , Microssomos Hepáticos , Ratos , Eliminação Renal , Ésteres do Ácido Sulfúrico/administração & dosagem , Distribuição Tecidual
16.
Drug Metab Dispos ; 49(12): 1109-1117, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34625435

RESUMO

Linerixibat, an oral small-molecule ileal bile acid transporter inhibitor under development for cholestatic pruritus in primary biliary cholangitis, was designed for minimal absorption from the intestine (site of pharmacological action). This study characterized the pharmacokinetics, absorption, metabolism, and excretion of [14C]-linerixibat in humans after an intravenous microtracer concomitant with unlabeled oral tablets and [14C]-linerixibat oral solution. Linerixibat exhibited absorption-limited flip-flop kinetics: longer oral versus intravenous half-life (6-7 hours vs. 0.8 hours). The short intravenous half-life was consistent with high systemic clearance (61.9 l/h) and low volume of distribution (16.3 l). In vitro studies predicted rapid hepatic clearance via cytochrome P450 3A4 metabolism, which predicted human hepatic clearance within 1.5-fold. However, linerixibat was minimally metabolized in humans after intravenous administration: ∼80% elimination via biliary/fecal excretion (>90%-97% as unchanged parent) and ∼20% renal elimination by glomerular filtration (>97% as unchanged parent). Absolute oral bioavailability of linerixibat was exceedingly low (0.05%), primarily because of a very low fraction absorbed (0.167%; fraction escaping first-pass gut metabolism (fg) ∼100%), with high hepatic extraction ratio (77.0%) acting as a secondary barrier to systemic exposure. Oral linerixibat was almost entirely excreted (>99% recovered radioactivity) in feces as unchanged and unabsorbed linerixibat. Consistent with the low oral fraction absorbed and ∼20% renal recovery of intravenous [14C]-linerixibat, urinary elimination of orally administered radioactivity was negligible (<0.04% of dose). Linerixibat unequivocally exhibited minimal gastrointestinal absorption and oral systemic exposure. Linerixibat represents a unique example of high CYP3A4 clearance in vitro but nearly complete excretion as unchanged parent drug via the biliary/fecal route. SIGNIFICANCE STATEMENT: This study conclusively established minimal absorption and systemic exposure to orally administered linerixibat in humans. The small amount of linerixibat absorbed was eliminated efficiently as unchanged parent drug via the biliary/fecal route. The hepatic clearance mechanism was mispredicted to be mediated via cytochrome P450 3A4 metabolism in vitro rather than biliary excretion of unchanged linerixibat in vivo.


Assuntos
Administração Intravenosa , Administração Oral , Proteínas de Transporte/antagonistas & inibidores , Eliminação Hepatobiliar , Glicoproteínas de Membrana/antagonistas & inibidores , Metilaminas/farmacocinética , Eliminação Renal , Tiazepinas/farmacocinética , Adulto , Disponibilidade Biológica , Fármacos Gastrointestinais/farmacocinética , Voluntários Saudáveis , Eliminação Hepatobiliar/efeitos dos fármacos , Eliminação Hepatobiliar/fisiologia , Humanos , Absorção Intestinal , Masculino , Taxa de Depuração Metabólica , Eliminação Renal/efeitos dos fármacos , Eliminação Renal/fisiologia , Resultado do Tratamento
17.
Drug Metab Dispos ; 49(12): 1047-1055, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34593616

RESUMO

Exemestane (EXE) is a hormonal therapy used to treat estrogen receptor-positive breast cancer by inhibiting the final step of estrogen biosynthesis catalyzed by the enzyme aromatase. Cysteine conjugates of EXE and its active metabolite 17ß-dihydro-EXE (DHE) are the major metabolites found in both the urine and plasma of patients taking EXE. The initial step in cysteine conjugate formation is glutathione conjugation catalyzed by the glutathione S-transferase (GST) family of enzymes. The goal of the present study was to identify cytosolic hepatic GSTs active in the GST-mediated metabolism of EXE and 17ß-DHE. Twelve recombinant cytosolic hepatic GSTs were screened for their activity against EXE and 17ß-DHE, and glutathionylated EXE and 17ß-DHE conjugates were detected by ultra-performance liquid chromatography tandem mass spectrometry. GST α (GSTA) isoform 1, GST µ (GSTM) isoform 3 and isoform 1 were active against EXE, whereas only GSTA1 exhibited activity against 17ß-DHE. GSTM1 exhibited the highest affinity against EXE with a Michaelis-Menten constant (KM) value that was 3.8- and 7.1-fold lower than that observed for GSTA1 and GSTM3, respectively. Of the three GSTs, GSTM3 exhibited the highest intrinsic clearance against EXE (intrinsic clearance = 0.14 nl·min-1·mg-1). The KM values observed for human liver cytosol against EXE (46 µM) and 17ß-DHE (77 µM) were similar to those observed for recombinant GSTA1 (53 and 30 µM, respectively). Western blot analysis revealed that GSTA1 and GSTM1 composed 4.3% and 0.57%, respectively, of total protein in human liver cytosol; GSTM3 was not detected. These data suggest that GSTA1 is the major hepatic cytosolic enzyme involved in the clearance of EXE and its major active metabolite, 17ß-DHE. SIGNIFICANCE STATEMENT: Most previous studies related to the metabolism of the aromatase inhibitor exemestane (EXE) have focused mainly on phase I metabolic pathways and the glucuronidation phase II metabolic pathway. However, recent studies have indicated that glutathionylation is the major metabolic pathway for EXE. The present study is the first to characterize hepatic glutathione S-transferase (GST) activity against EXE and 17ß-dihydro-EXE and to identify GST α 1 and GST µ 1 as the major cytosolic GSTs involved in the hepatic metabolism of EXE.


Assuntos
Androstadienos/farmacocinética , Neoplasias da Mama , Glutationa Transferase/metabolismo , Inativação Metabólica/fisiologia , Fígado/enzimologia , Antineoplásicos Hormonais/farmacocinética , Inibidores da Aromatase/farmacocinética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Cromatografia Líquida , Cisteína/metabolismo , Citosol/metabolismo , Estrogênios/biossíntese , Glutationa Transferase/química , Eliminação Hepatobiliar/fisiologia , Humanos , Isoformas de Proteínas , Receptores de Estrogênio
18.
Drug Metab Dispos ; 49(12): 1070-1080, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34493602

RESUMO

The legalization of cannabis in many parts of the United States and other countries has led to a need for a more comprehensive understanding of cannabis constituents and their potential for drug-drug interactions. Although (-)-trans-Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN) are the most abundant cannabinoids present in cannabis, THC metabolites are found in plasma at higher concentrations and for a longer duration than that of the parent cannabinoids. To understand the potential for drug-drug interactions, the inhibition potential of major cannabinoids and their metabolites on major hepatic cytochrome P450 (P450) enzymes was examined. In vitro assays with P450-overexpressing cell microsomes demonstrated that the major THC metabolites 11-hydroxy-Δ9-tetra-hydrocannabinol and 11-nor-9-carboxy-Δ9-THC-glucuronide competitively inhibited several major P450 enzymes, including CYP2B6, CYP2C9, and CYP2D6 (apparent Ki,u values = 0.086 ± 0.066 µM and 0.90 ± 0.54 µM, 0.057 ± 0.044 µM and 2.1 ± 0.81 µM, 0.15 ± 0.067 µM and 2.3 ± 0.54 µM, respectively). 11-Nor-9-carboxy-Δ9- tetrahydrocannabinol exhibited no inhibitory activity against any CYP450 tested. THC competitively inhibited CYP1A2, CYP2B6, CYP2C9, and CYP2D6; CBD competitively inhibited CYP3A4, CYP2B6, CYP2C9, CYP2D6, and CYP2E1; and CBN competitively inhibited CYP2B6, CYP2C9, and CYP2E1. THC and CBD showed mixed-type inhibition for CYP2C19 and CYP1A2, respectively. These data suggest that cannabinoids and major THC metabolites are able to inhibit the activities of multiple P450 enzymes, and basic static modeling of these data suggest the possibility of pharmacokinetic interactions between these cannabinoids and xenobiotics extensively metabolized by CYP2B6, CYP2C9, and CYP2D6. SIGNIFICANCE STATEMENT: Major cannabinoids and their metabolites found in the plasma of cannabis users inhibit several P450 enzymes, including CYP2B6, CYP2C9, and CYP2D6. This study is the first to show the inhibition potential of the most abundant plasma cannabinoid metabolite, THC-COO-Gluc, and suggests that circulating metabolites of cannabinoids play an essential role in CYP450 enzyme inhibition as well as drug-drug interactions.


Assuntos
Canabidiol/metabolismo , Canabinoides , Canabinol/metabolismo , Cannabis , Sistema Enzimático do Citocromo P-450 , Dronabinol/análogos & derivados , Interações Medicamentosas/fisiologia , Biotransformação , Canabinoides/classificação , Canabinoides/metabolismo , Inibidores das Enzimas do Citocromo P-450/farmacocinética , Sistema Enzimático do Citocromo P-450/análise , Sistema Enzimático do Citocromo P-450/classificação , Dronabinol/metabolismo , Glucuronosiltransferase/metabolismo , Células HEK293 , Eliminação Hepatobiliar/efeitos dos fármacos , Humanos
19.
Artigo em Inglês | MEDLINE | ID: mdl-34419711

RESUMO

Laboratory measurements of intrinsic clearance support the development of TK models, with potential relevance to weight of evidence toxicity assessments of xenobiotics, including read-across, the concept of predictive estimation by data extrapolation between chemicals of similar structure (analogues). In this work a procedure with analytical method for determination of in vitro hepatic metabolic clearance, relevant to biotransformation toxicokinetic (TK) modelling, is presented. Cryopreserved primary human hepatocytes represent a suitable cells, due to their biological characteristics, for providing an in vitro model for simulating in vivo metabolic clearance. The experimental part considered an adequate sequential time-frame for collecting samples and controls for all chemicals tested, including centrifugation and aliquoting of the corresponding fractions until the instrumental session. For the first time, in vitro hepatocyte intrinsic clearance was measured for six analogue test chemicals: valproic acid, 2-ethyl caproic acid, octanoic acid, valeric acid, 2-methyl butyric acid and 2-trans pentenoic acid, during incubated cell culture exposure up to 2 h or 3.5 h. The time dependence of any metabolism was determined from analysis of the supernatant at intervals using a new developed analytical method for UPLC coupled with QTOF mass spectrometer. The chemicals could then be ranked by their relative intrinsic clearance. The analyses were reproducible, with coherence of the calculated in vitro intrinsic clearance between experiments.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Eliminação Hepatobiliar/fisiologia , Fígado/metabolismo , Espectrometria de Massas/métodos , Ácido Valproico , Células Cultivadas , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Limite de Detecção , Modelos Lineares , Fígado/citologia , Reprodutibilidade dos Testes , Ácido Valproico/análogos & derivados , Ácido Valproico/análise , Ácido Valproico/metabolismo
20.
Mol Pharm ; 18(9): 3563-3577, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34428046

RESUMO

Liver cirrhosis is a chronic disease that affects the liver structure, protein expression, and overall metabolic function. Abundance data for drug-metabolizing enzymes and transporters (DMET) across all stages of disease severity are scarce. Levels of these proteins are crucial for the accurate prediction of drug clearance in hepatically impaired patients using physiologically based pharmacokinetic (PBPK) models, which can be used to guide the selection of more precise dosing. This study aimed to experimentally quantify these proteins in human liver samples and assess how they can impact the predictive performance of the PBPK models. We determined the absolute abundance of 51 DMET proteins in human liver microsomes across the three degrees of cirrhosis severity (n = 32; 6 mild, 13 moderate, and 13 severe), compared to histologically normal controls (n = 14), using QconCAT-based targeted proteomics. The results revealed a significant but non-uniform reduction in the abundance of enzymes and transporters, from control, by 30-50% in mild, 40-70% in moderate, and 50-90% in severe cirrhosis groups. Cancer and/or non-alcoholic fatty liver disease-related cirrhosis showed larger deterioration in levels of CYP3A4, 2C8, 2E1, 1A6, UGT2B4/7, CES1, FMO3/5, EPHX1, MGST1/3, BSEP, and OATP2B1 than the cholestasis set. Drug-specific pathways together with non-uniform changes of abundance across the enzymes and transporters under various degrees of cirrhosis necessitate the use of PBPK models. As case examples, such models for repaglinide, dabigatran, and zidovudine were successful in recovering disease-related alterations in drug exposure. In conclusion, the current study provides the biological rationale behind the absence of a single dose adjustment formula for all drugs in cirrhosis and demonstrates the utility of proteomics-informed PBPK modeling for drug-specific dose adjustment in liver cirrhosis.


Assuntos
Relação Dose-Resposta a Droga , Eliminação Hepatobiliar/fisiologia , Cirrose Hepática/fisiopatologia , Fígado/metabolismo , Modelos Biológicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Fígado/citologia , Fígado/patologia , Cirrose Hepática/diagnóstico , Masculino , Microssomos Hepáticos , Pessoa de Meia-Idade , Proteômica , Índice de Gravidade de Doença
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...