RESUMO
A microdetermination of propranolol enantiomers and of their glucuronide and sulphate conjugates in human plasma and urine by reversed-phase HPLC after chiral derivatization is described. After extraction from 100 microliters of plasma or urine with racemic 4-methylpropranolol as internal standard (I.S.), the enantiomers are derivatized with R(+)-phenylethylisocyanate as chiral derivatization reagent. Chromatography is performed on Novapak C18 column with fluorescence detection. Glucuronide and sulphate conjugates are cleaved prior to extraction by incubating, respectively, the samples with glucuronidase-arylsulphatase and saccharic acid 1-4 lactone as specific glucuronidase inhibitor. The retention times of propranolol and I.S. enantiomer derivatives are short (tR = 5.5-6.2 min and 8.8-10.1 min, respectively). The diastereomeric derivatives are very stable and show good peak symmetry and resolutions (RS = 2 and 2.2). The use of 4-methylpropranolol as I.S. improves significantly relative standard deviations (RSD: 1.7-5.1). Sensitivity is about 1 ng ml-1 per enantiomer. The method is applied to pharmacokinetic studies of racemic propranolol in human plasma and urine. S-propranolol and its conjugates show higher concentrations than R-propranolol and its conjugates in plasma and urine.
Assuntos
Propranolol/sangue , Propranolol/urina , Adulto , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Humanos , Masculino , Propranolol/análogos & derivados , Propranolol/farmacocinética , Padrões de Referência , EstereoisomerismoRESUMO
Thevetin B, a cardiac glycoside of Thevetia neriifolia Juss. seeds, was determined in serum by fluorescence polarization immunoassay. Anti-digitoxin antibody was used, thevetin B genin being structurally identical to digitoxigenin. Cross-reactivity of 94% was found by this method, for concentrations from 5 to 80 ng ml-1.
Assuntos
Cardenolídeos/sangue , Glicosídeos Cardíacos/sangue , Reações Cruzadas , Digitoxina/sangue , Imunoensaio de Fluorescência por Polarização/métodos , HumanosRESUMO
Gas capillary chromatography (GCC) determination of mannitol and lactulose in urine after oral intake is a method for assessing the intestinal permeability in various bowel diseases. The method proposed, using gas capillary chromatography with flame ionization detection after silylation of urine residue, gives good results: coefficients of variation varied from 6 to 8.7% for mannitol and 7.5 to 13.7% for lactulose. Detection limit was 5 mg/l for both compounds.
Assuntos
Ionização de Chama/métodos , Lactulose/urina , Manitol/urina , HumanosRESUMO
Fluorides and monofluorophosphates present in drugs, toothpastes and mineral waters are converted into an organic compound by trimethylchlorosilane at acidic pH. The trimethylfluorosilane formed is determined with isopentane as internal standard by gas liquid chromatography with flame ionization detection. Some drugs containing fluoride at therapeutic or physiologic concentrations also some toothpastes and mineral waters were analyzed easily by this method. No interferences due to excipients or to other active substances present in drugs or toothpastes were observed with this method. Because of its sensitivity (0.01 ppm), its accuracy (CV: 0.7 à 2%) and its simplicity, the chromatographic method proposed is suitable for the routine controls of fluorides in drugs, toothpastes and mineral waters.
Assuntos
Fluoretos/análise , Águas Minerais/análise , Preparações Farmacêuticas/química , Fosfatos/análise , Cremes Dentais , Cromatografia GasosaRESUMO
The apparition of cyclosporine, immunodepressive drug, has largely improved the organ transplantations. However, the range of blood concentrations must be defined to allow the efficacity of cyclosporine therapy and to avoid toxic reactions, because there are very important variations for a same dosage according to the individuals and the diseases. Relative to the low concentrations to be determined (about one hundred ng/ml), the most useful methods for cyclosporine measurement are based on immunochemical assays. This work compare the two methods: radioimmunoassay (RIA) and fluorescence polarization immunoassay (FPIA) simultaneously performed on several hundred samples. A very significant correlation exists between the two techniques (r = 0,80). The advantages of immunofluorescent assay consists in rapidity, sensibility and facility to realize emergency analysis.
Assuntos
Ciclosporinas/sangue , Imunofluorescência , Radioimunoensaio , Transplante de Medula Óssea , Estudos de Avaliação como Assunto , Polarização de Fluorescência , Humanos , Transplante de RimRESUMO
The determination of propranolol enantiomers in microsamples of human plasma and urine by HPLC using a chiral stationary phase is described. After extraction from 200 microliters of plasma or urine with racemic alprenolol as internal standard (I.S.), the enantiomers are separated on a beta-cyclodextrin column with a polar organic mobile phase and determined by fluorescence detection. The retention times of I.S. and propranolol enantiomers are about 12-13 min and 16-18 min, respectively. Peak resolutions are 1.4 for I.S. and 2.2 for propranolol. The use of alprenolol as I.S. improves significantly the coefficients of variation (C.V.: 0.6-4.2%). Sensitivity is approximately 1.5 ng/ml per propranolol enantiomer. The assay is applied to pharmacokinetic studies of racemic propranolol in human biological fluids. The (S)-propranolol levels are always higher than the (R)-antipode concentrations in plasma and urine.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Propranolol/sangue , Propranolol/urina , beta-Ciclodextrinas , Ciclodextrinas/química , Humanos , Padrões de Referência , EstereoisomerismoRESUMO
A rapid high-performance liquid chromatographic assay with isocratic elution is developed for the simultaneous quantification of valaciclovir (VACV) prodrug and its active converted compound, acyclovir (ACV), in biological fluids of treated patients. For serum, the samples are deproteinized with perchloric acid in presence of 1-methylguanosine as the internal standard (IS). For urine and dialysis liquid, the samples are diluted with a mobile phase containing the IS, then filtered. VACV, ACV and the IS are separated on a SymmetryShield RP-8 column with acetonitrile-ammonium phosphate buffer as the mobile phase and detected at 254 nm. The chromatographic time is about 12 min. The relative standard deviations (RSD) of VACV and ACV standards are between 0.5 and 3.5%. Most endogenous nucleosides and their metabolites, psychotropic drugs and drugs of abuse are shown not to interfere with this technique. The method has been applied to study the pharmacokinetics of VACV and ACV in serum, dialysis liquid and urine of renal failure patients on continuous ambulatory peritoneal dialysis (CAPD) under oral treatment of VACV.
Assuntos
Aciclovir/análogos & derivados , Aciclovir/análise , Líquidos Corporais/química , Cromatografia Líquida de Alta Pressão/métodos , Valina/análogos & derivados , Aciclovir/farmacocinética , Aciclovir/urina , Antivirais/análise , Antivirais/farmacocinética , Antivirais/urina , Humanos , Insuficiência Renal/metabolismo , Reprodutibilidade dos Testes , Valaciclovir , Valina/análise , Valina/farmacocinética , Valina/urinaRESUMO
The potential nephrotoxicity of cyclosporine A (CsA), its three main metabolites: M1, M17 and M21, and its two analogues: cyclosporines C and D (CsC, CsD) was evaluated in vitro in suspensions of freshly isolated rabbit renal proximal tubular cells. This assessment involved the measure of enzyme release in the incubation media and the determination of Na+/K(+)-ATPase activity and glutathione content directly in the tubular cells. In vitro nephrotoxicity results of the six compounds tested could be respectively schematized as: CsA > CsD > CsC > M21 > M17, M1 It would be interesting to promote the study of promising CsC because of its low nephrotoxicity and its high immunosuppressive potency as previously reported.
Assuntos
Ciclosporinas/toxicidade , Túbulos Renais Proximais/efeitos dos fármacos , Animais , Aspartato Aminotransferases/metabolismo , Células Cultivadas , Ciclosporina/metabolismo , Ciclosporina/toxicidade , Ciclosporinas/metabolismo , Feminino , Glutationa/metabolismo , Túbulos Renais Proximais/enzimologia , Túbulos Renais Proximais/metabolismo , L-Lactato Desidrogenase/metabolismo , Coelhos , ATPase Trocadora de Sódio-Potássio/metabolismo , Relação Estrutura-Atividade , gama-Glutamiltransferase/metabolismoRESUMO
A rapid gas-liquid chromatographic assay is developed for the quantification of methadone (Mtd) and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in biological fluids of opiate addicts. After alkaline extraction from samples with lidocaine hydrochloride as internal standard, Mtd and EDDP are separated on SP-2250 column at 220 degrees C and detected with a thermionic detector. The chromatographic time is about 6 min. The relative standard deviations (R.S.D.) of Mtd and EDDP standards are between 1.5 and 5.5%. Most drugs of abuse (morphine, codeine, narcotine, cocaine, benzoylecgonine, cocaethylene, dextropropoxyphene etc) are shown not to interfere with this technique. The method has been applied to study the levels of Mtd and EDDP metabolite in serum, saliva and urine of patients under maintenance treatment for opiate dependence. EDDP levels were found higher than those of Mtd in urine samples from four treated patients, but lower in serum and undetectable in saliva. However, Mtd concentrations were higher in saliva than in serum.
Assuntos
Cromatografia Gasosa/métodos , Metadona/metabolismo , Transtornos Relacionados ao Uso de Opioides/metabolismo , Pirrolidinas/metabolismo , Saliva/metabolismo , Artefatos , Humanos , Metadona/sangue , Metadona/urina , Transtornos Relacionados ao Uso de Opioides/sangue , Transtornos Relacionados ao Uso de Opioides/urina , Pirrolidinas/sangue , Pirrolidinas/urina , Reprodutibilidade dos TestesRESUMO
Selective antibodies to (R)-methadone (Mtd) and to its racemate were produced in rabbits by immunization with conjugates of (R)- or (R,S)-hemisuccinyl-methadol-bovine serum albumin, respectively. A hapten was first prepared by reduction of (R)- or (R,S)-Mtd with sodium borohydride, followed by esterification with succinic anhydride. The conjugation of hapten with albumin was achieved by the mixed anhydride method. After immunization of rabbits, the titers and specificity of each antibody were determined by ELISA. The antibodies obtained were tested with (R)-, (S)-, (R,S)-Mtd, its major metabolite (EDDP), and some drugs of abuse (morphine, codeine, cocaine). The sensitivities of antibodies to (R)- and (R,S)-Mtd were about 1 and 2 ng/ml, respectively. Selective (R)-antibodies recognized (R)-Mtd about 40 times more avidly than the (S)-isomer, while an antiserum against (R,S)-Mtd recognized (R)- and (S)-isomers to about the same degree. Both selective antibodies showed little interference (about 0.5%) with EDDP metabolite and no crossreactivity with morphine, codeine, and cocaine. These two selective antibodies were used to develop an immunoenzymatic method (ELISA) for the determination of (R)- and (R,S)-Mtd in serum samples of patients under maintenance treatment for narcotic addiction.
Assuntos
Metadona/sangue , Metadona/imunologia , Animais , Especificidade de Anticorpos , Bovinos , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/normas , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Humanos , Metadona/análogos & derivados , Metadona/síntese química , Coelhos , Sensibilidade e Especificidade , Soroalbumina Bovina , EstereoisomerismoRESUMO
A selective antibody to (S)-propranolol enantiomer was produced in rabbits by immunization with a new conjugate of N-aminopropylpropranolol-albumin. A hapten was first prepared by condensing (S)-propranolol or the racemate with 3-bromopropylphthalimide followed by hydrazinolysis, and the resulting compound conjugated to serum albumin by means of a glutaraldehyde- or carbodiimide-mediated reaction. Rabbits were immunized, and titres and specificity of antibodies were determined by ELISA. The antibodies obtained were tested with (S)-, (R)-, (R,S)-propranolol, and other structural analogs. Selective (S)-antibodies recognized (S)-propranolol 20 times more avidly than (R)-isomer while an antiserum against (R,S)-propranolol recognized both (S)- and (R)-isomers to about the same degree.
Assuntos
Anticorpos , Propranolol/imunologia , Animais , Especificidade de Anticorpos , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Haptenos , Imunização , Propranolol/química , Coelhos , Albumina Sérica/imunologia , EstereoisomerismoRESUMO
Cyclosporin G (CsG), a promising cyclosporin A (CsA) analogue, was examined and compared with two reference immunosuppressive drugs: CsA and FK-506, regarding their inhibitory effects on different lymphocyte activation pathways as well as on graft-versus-host reaction (GvHR) across differences at major or minor histocompatibility loci. The results showed that, at different concentrations, CsG efficiently inhibited proliferation induced by alloantigens (mixed lymphocyte culture), mitogens (concanavalin A, pokeweed mitogen) and the combination of phorbol myristate acetate + ionomycin, to the same extent as observed with CsA and FK-506. It was also shown that CsG exhibited the same strong inhibitory effects as the two other immunosuppressants upon stimulation triggered by viral (MLs-1a) or bacterial (staphylococcal enterotoxin B) superantigen. Determination of IL-2 activity in the supernatant of MLC also confirmed similar strong inhibitory effects, exerted by CsG compared to CsA and FK-506. In systemic and local GvHR across major or minor histocompatibility barriers, CsG as well as CsA and FK-506 presented an equivalent immunosuppressive potential. In conclusion, from various experiments involving different modes of activation, it was shown that CsG was as strongly immunosuppressive as CsA and FK-506.
Assuntos
Ciclosporina/farmacologia , Imunossupressores/farmacologia , Tacrolimo/farmacologia , Animais , Células Cultivadas , Reação Enxerto-Hospedeiro/efeitos dos fármacos , Interleucina-2/biossíntese , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Endogâmicos DBARESUMO
Cyclosporin A (CsA) is in vivo mainly metabolized by hepatic cytochrome P450 IIIA to more than 21 metabolites, the major ones known as: M1, M17 and M21. The aim of this work is to explore the in vitro metabolism of CsA after incubation, in the presence of NADPH, with renal or hepatic microsomes obtained from rabbits pretreated with rifampycin (enzyme inducer) or erythromycin (enzyme inhibitor). The presumed metabolites were separated by semi-preparative high-performance liquid chromatography (HPLC) and identified in each collected fraction by fluorescence polarization immunoassay (FPIA) (HPLC-FPIA) using a non-specific polyclonal antibody. They were also analyzed by HPLC-mass spectrometry (MS) using fast atom bombardment (HPLC-MS-FAB). Five collected fractions gave positive results with FPIA. The major metabolites found were M1, M17 and M21 after identification by HPLC-MS-FAB and comparison with three corresponding standard metabolites. The CsA biotransformation rates were calculated by the amount of unmetabolized CsA and were linear with time. These mean rates (Vm) for 12-min incubation by renal microsomes of rabbits treated with rifampicin or erythromycin or untreated (control) were 0.11, 0.02 and 0.04 nmol/min x mg microsomal protein, respectively. These rates were 15-, 37-, and 30-fold lower than those obtained with hepatic microsomes of rabbits treated identically. As CsA metabolites are less cytotoxic than the parent drug, this weak renal biotransformation of CsA after in vitro incubation should be one of the mechanisms of its in vivo nephrotoxicity.
Assuntos
Ciclosporina/metabolismo , Rim/metabolismo , Rim/ultraestrutura , Microssomos Hepáticos/metabolismo , Animais , Cromatografia Líquida de Alta Pressão/métodos , Masculino , Microssomos/metabolismo , CoelhosRESUMO
FK506, cyclosporin A (CsA), and its structural analog cyclosporin G (CsG) are immunosuppressant drugs mainly metabolized by hepatic cytochrome P-450 3A (CYP 3A) oxygenase. FK506 metabolites exhibit greater toxicity than the parent drug, while CsA metabolites are far less toxic than CsA itself. The aim of our study was to compare the toxicity of CsG with CsA and FK506 as a function of CYP 3A induction. Hepatocytes from Wistar rats with or without dexamethasone (DEX) induction (200 mg/kg per day, p.o for 4 days) were used in primary culture. The DEX-inductive effect on CYP 3A was assessed by SDS-PAGE. After 6 h incubation with CsG, CsA or FK506 (5 to 200 microM), cell viability (expressed as IC50), intracellular calcium content and apoptosis were evaluated. Concerning cytotoxicity, IC50 values for CsG, CsA and FK506 were 75, 50 and 180 microM respectively in non-induced cultures, and 150, 120 and 25 microM in induced cultures. For intracellular calcium content, a dose-dependent increase was observed in all cultures. However this increase is more important for CsG and CsA in non-induced cultures (150%) compared to induced cultures (110%) at 150 microM. Conversely for FK506, this increase is greater in induced cultures (150%) than in non-induced cultures (127%). Estimation of the percentage of apoptotic cells shows similar variations. Our results show that the toxicity of the three drugs in rat hepatocytes is dependent on CYP 3A induction: increased for FK506, decreased for CsA and CsG. Moreover, with regard to the three tests used, the toxic effects of CsG are close to those of CsA, indicating that CsG metabolites are also less toxic than the parent drug.
Assuntos
Hidrocarboneto de Aril Hidroxilases , Sistema Enzimático do Citocromo P-450/fisiologia , Imunossupressores/toxicidade , Fígado/efeitos dos fármacos , Fígado/enzimologia , Oxirredutases N-Desmetilantes/fisiologia , Animais , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Corantes , Ciclosporina/toxicidade , Citocromo P-450 CYP3A , Citometria de Fluxo , Líquido Intracelular/efeitos dos fármacos , Líquido Intracelular/metabolismo , Fígado/patologia , Masculino , Ratos , Ratos Wistar , Tacrolimo/toxicidade , Sais de Tetrazólio , TiazóisRESUMO
Cyclosporine A (CsA) and its major metabolites: M1, M17 and M21 and two analogues: cyclosporines C (CsC) and D (CsD), were studied for their capacity to interfere with different in vitro activation pathways. Their inhibition potentials against the reaction of Graft-versus-Host (GvH) were also studied. The results showed: CsA, CsC and metabolite M17 were the most active compounds upon the inhibition of lymphocyte proliferation induced by different mitogens (ConA, PHA, PWM) and also on the proliferation of mixed lymphocyte cultures (MLC). The same results were observed concerning the direct activation by protein kinase C using a combined action of phorbol ester + calcium ionophore. In vivo using local GvH reaction, CsA and CsC proved more active than M17 in the two different combinations: H-2d --> (H-2b x H-2d)F1 and H-2k --> (H-2b x H-2k)F1 CsD and two metabolites M1 and M21 showed no or weak immunosuppressive effects. Overall, the immunosuppressive potency of six compounds could be schematized as: CsA > or = CsC > M17 > M1 > or = CsD > M21.
Assuntos
Ciclosporinas/farmacologia , Imunossupressores/farmacologia , Animais , Calcimicina/farmacologia , Ciclosporina/metabolismo , Ciclosporina/farmacologia , Ciclosporinas/química , Ciclosporinas/metabolismo , Reação Enxerto-Hospedeiro/efeitos dos fármacos , Técnicas In Vitro , Isoantígenos , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos , Mitógenos/farmacologia , Relação Estrutura-AtividadeRESUMO
The present study was undertaken to evaluate the effects of platelet activating factor (PAF) antagonists, PMS 536 and PMS 549, on LLC-PK1 toxicity induced by Cyclosporin A (CsA). The LLC-PK1 cell line was used as an in vitro model. CsA cytotoxicity was determined in relation with ATP content. Alkaline phosphatase and N-acetyl-beta-glucosaminidase activities, which are directly correlated with tubular cell damage, were used as markers for renal injury. CsA alone provoked in the LLC-PK1 cell line a marked decrease in cell viability (55%) and membrane integrity (56%), and a significant increase in AP and NAG activities and in oxidized glutathione level. The ATP decrease and the ADP increase, resulting in a decline of the ATP/ADP ratio, is indicative of an anoxic energy charge. Co-treatment with CsA plus PMS 536 or PMS 549 resulted in a minor decrease in cell viability and in significant membrane integrity recovery. Moreover, the ATP depletion and the increase in ATP metabolites, hypoxanthine and uric acid induced by CsA were strongly prevented by PAF antagonists. In contrast, GSSG level remained high as in CsA-treated cells, but GSH level was in the range of controls. Our results suggest that both PAF antagonists attenuate CsA oxidative injury and prevent energy metabolism disturbances probably by maintaining cell integrity. The lipophilicity of both molecules may be responsible for membrane stabilization and may confer the protective effects observed in energy metabolism. The results obtained with PMS 536 and PMS 549 are indicative of interactions between PAF and CsA in renal injury and suggest the therapeutic potential of these PAF-antagonists against CsA-induced nephrotoxicity.
Assuntos
Ciclosporina/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Piperazinas/farmacologia , Fator de Ativação de Plaquetas/antagonistas & inibidores , Inibidores da Agregação Plaquetária/farmacologia , Acetilglucosaminidase/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Ciclosporina/toxicidade , Glutationa/metabolismo , Glutationa Peroxidase/metabolismo , Nefropatias/induzido quimicamente , Nefropatias/prevenção & controle , Células LLC-PK1 , SuínosRESUMO
The simultaneous determination of methadone (Mtd) enantiomers and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), in human urine and serum by enantioselective HPLC using a new Cyclobond 1-2000 RSP column is described. After alkaline extraction from urine or serum with estazolam as an internal standard, Mtd enantiomers and its metabolite (EDDP) are separated on the previous column with reversed-mobile phase and detected at 210 nm. Peak resolutions are about 2.0 for Mtd enantiomers. The relative standard deviations (R.S.D.) of Mtd and EDDP standards are between 0.5 and 4.5%. Most drugs of abuse are shown not to interfere with this technique. The method has been applied to study the levels of each Mtd enantiomer and of its racemic metabolite in urine and serum of patients under maintenance treatment for opiate dependence. In urine, R-(-)-Mtd levels are always higher (about 2+/-0.5-fold) than those of S-(+)-Mtd and in most cases, metabolite concentrations are greater than those of global Mtd enantiomers. However, the R-(-) enantiomer levels of residual drug in serum of some patients were lower than those of its antipode. This method is suitable for pharmacokinetic and toxicological studies of Mtd enantiomers and its major metabolite in biological fluids.
Assuntos
Analgésicos Opioides/sangue , Analgésicos Opioides/urina , Metadona/sangue , Metadona/urina , Transtornos Relacionados ao Uso de Opioides/reabilitação , Pirrolidinas/sangue , Pirrolidinas/urina , Analgésicos Opioides/uso terapêutico , Cromatografia Líquida de Alta Pressão/métodos , Ciclodextrinas , Humanos , Metadona/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/sangue , Transtornos Relacionados ao Uso de Opioides/urina , Reprodutibilidade dos Testes , EstereoisomerismoRESUMO
FK506 and cyclosporin A (CsA) are two potent immunosupressants with similar toxicity profile. Nephrotoxicity is the main adverse effect of both compounds. The aim of this study is to compare the in vitro nephrotoxic effects on renal epithelial cell line LLC-PK1 by measuring cell viability and energy status as evaluated by concentrations of ATP and ATP metabolites. Cell viability (expressed as IC50 was assessed via thiazolyl blue (MTT) assay after incubation for 4-24 h with FK506 or CsA. ATP and its metabolites were determined by HPLC after 4 and 6 h incubation with FK506 or CsA alone at the respective IC50. Both FK506 and CsA decreased cell viability to similar extents, in a dose- and time-dependent manner. After 4 h incubation, both drugs decreased ATP levels (-25%) and increased uric acid levels. However, the latter percentage increase was twofold higher with CsA (18%) than with FK506 (9%). The energy charge, calculated according to levels of adenine nucleotides, was decreased by 10% in FK506-treated cells and by 27% in CsA-treated cells. At the end of 6-h incubation, FK506-treated cells maintained ATP levels coupled with energy charge at near control levels whereas the levels were 32% lower in CsA treated cells. Compared to the 4 h-incubation, the increase in uric acid was similar for FK506 but was doubled with CsA. The decrease in cell integrity and ATP depletion induced by CsA in LLC-PK1 cells was only transiently observed with FK506. By preserving energy status, FK506 leads to fewer metabolic disturbances than CsA in the renal epithelial cell line LLC-PK1, demonstrating a minor potential nephrotoxicity.
Assuntos
Ciclosporina/toxicidade , Metabolismo Energético/efeitos dos fármacos , Imunossupressores/toxicidade , Tacrolimo/toxicidade , Trifosfato de Adenosina/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Rim/citologia , Rim/efeitos dos fármacos , Células LLC-PK1 , Nucleotídeos/metabolismo , Suínos , Sais de Tetrazólio/toxicidade , Tiazóis/toxicidade , Fatores de TempoRESUMO
Rabbit renal microsomes were used to investigate the effect on lipid peroxidation (LPO) of cyclosporin A (CsA) and its first generation metabolites M1, M17 and M21, and of two natural CsA analogs: cyclosporins C and D (CsC & CsD respectively), at concentrations of 1 to 10 micrograms/ml. No induction of lipid peroxidation was observed with these substances except CsA at a high level (10 microgram/ml); but at a concentration of CsA that would be reached in vivo, no inductive effect on LPO was noted. A moderate inhibitory effect upon LPO was observed with CsC and M21, but its biological significance is questionable.
Assuntos
Ciclosporina/farmacologia , Ciclosporinas/farmacologia , Rim/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Microssomos/efeitos dos fármacos , Animais , Ciclosporina/metabolismo , Ciclosporinas/metabolismo , Feminino , Rim/metabolismo , Cinética , Malondialdeído/metabolismo , Microssomos/metabolismo , CoelhosRESUMO
Composition of gas generated by the utilisation of Nd-Yag laser in eyes filled with silicone oil were studied by means of an in vitro optical breakdown in silicone oil. The newly formed gas were analysed by headspace gas chromatography on two separate columns. The secondary gas were mainly methane and ethylene which might be potentially harmful to the ocular tissues.