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2.
Cryo Letters ; 43(2): 110-119, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36626152

RESUMEN

BACKGROUND: Using sulfated polysaccharides (SP) in fish sperm freezing medium promotes cell maintenance. OBJECTIVE: To evaluate the effect of different SP concentrations, extracted from two seaweeds (Gracilaria domingensis and Ulva fasciata), as a supplement to the sperm freezing medium of Prochilodus brevis. MATERIALS AND METHODS: Five semen pools were diluted in a solution composed of 5% glucose, 10 % dimethyl sulfoxide (DMSO) and different SP concentrations (0, 0.5, 1.0, 1.5, 2.0, 2.5 or 3.0 mg/mL). The samples were cryopreserved and, after 7 days, rewarmed and analyzed for morphology, plasma membrane integrity, DNA integrity, mitochondrial activity and sperm kinetics [total motility, progressive motility, curvilinear velocity (VCL), straight line velocity (VSL), average path velocity (VAP), linearity (LIN), and wobble (WOB)]. RESULTS: There was no interaction between seaweed and SP concentrations. Similar effects were observed with SP extracted from the two seaweeds, regardless of concentration. When comparing the SP concentrations, regardless of the seaweed, 1.0 mg/mL SP showed better results for VCL and VSL. For VAP and WOB, 1.0 mg/mL SP showed better results, but differed from 3.0 mg/mL. LIN followed the same pattern, but differed from SP at 2.5 and 3.0 mg/mL. For progressive motility, 1.0 mg/mL G. domingensis showed superior results compared to the control. For mitochondrial activity, G. domingensis was superior to U. fasciata, regardless of concentration. The lowest concentrations (0.5 and 1.0 mg/mL) showed the best results, regardless of the seaweed. However, the control was superior to all treatments tested. CONCLUSION: G. domingensis SP at the lowest concentrations might be a potential supplement to the P. brevis freezing medium. doi.org/10.54680/fr22210110412.


Asunto(s)
Characiformes , Preservación de la Fertilidad , Preservación de Semen , Animales , Masculino , Congelación , Criopreservación/métodos , Sulfatos , Motilidad Espermática , Preservación de Semen/veterinaria , Preservación de Semen/métodos , Espermatozoides , Glucosa
3.
J Endocrinol Invest ; 44(11): 2455-2463, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33788166

RESUMEN

PURPOSE: There are no data regarding periodontal derangements in patients with adrenal incidentalomas (AI). We assessed the frequency and severity of periodontitis in patients with AI [non-functioning adrenal incidentaloma (NFAI) and possible autonomous cortisol secretion (ACS)] and compared with individuals with normal adrenal. METHODS: A cross-sectional study evaluated thirty-five individuals with AI and 26 controls. NFAI and possible ACS diagnosis was based on the current guidelines: NFAI [cortisol levels after 1 mg dexamethasone suppression test (1 mg-DST) ≤ 1.8 µg/dL (≤ 50 nmol/L)]; possible ACS [cortisol levels after 1 mg-DST 1.9-5.0 µg/dL (51-138 nmol/L)]. Sociodemographic data were collected, and a full-mouth periodontal evaluation was performed. RESULTS: There was no significant difference between groups regarding age, sex, income, ethnicity, education level, smoking, body mass index, dysglycemia, and arterial hypertension. Patients with AI exhibited worse periodontal conditions than controls for the following periodontal clinical parameters: mean percentage of probing pocket depth (PPD) and clinical attachment level (CAL) ≥ 5 mm (p < 0.001 and p = 0.006, respectively). Patients with NFAI and possible ACS showed higher gingival bleeding index (p = 0.014), bleeding on probing (p < 0.001), and CAL (p < 0.001) means compared to controls. The frequencies of periodontitis were 72.7% in patients with NFAI, 84.6% in possible ACS, and 30.8% in controls (p = 0.001). Periodontitis was more severe in patients with possible ACS than NFAI and controls. Patients with NFAI and possible ACS exhibited odds ratio for periodontitis of 4.9 (p = 0.016) and 8.6 (p = 0.02), respectively. CONCLUSION: Patients with AI have higher frequency and severity of periodontitis than controls. The presence of AI was an independent predictive factor for periodontitis.


Asunto(s)
Neoplasias de las Glándulas Suprarrenales , Glándulas Suprarrenales , Hidrocortisona , Periodontitis , Neoplasias de las Glándulas Suprarrenales/diagnóstico , Neoplasias de las Glándulas Suprarrenales/metabolismo , Neoplasias de las Glándulas Suprarrenales/fisiopatología , Glándulas Suprarrenales/metabolismo , Glándulas Suprarrenales/patología , Glándulas Suprarrenales/fisiopatología , Estudios Transversales , Diagnóstico Bucal/métodos , Técnicas de Diagnóstico Endocrino , Femenino , Humanos , Hidrocortisona/biosíntesis , Hidrocortisona/sangre , Masculino , Persona de Mediana Edad , Periodontitis/diagnóstico , Periodontitis/fisiopatología , Valor Predictivo de las Pruebas , Pronóstico , Medición de Riesgo/métodos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores Sociodemográficos
4.
Cryo Letters ; 42(5): 272-282, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35363848

RESUMEN

BACKGROUND: Sulfated polysaccharides from the skin of Nile tilapia (Oreochromis niloticus), added to the tambaqui (Colossoma macropomum) semen diluting medium, can be potential antioxidants and promote the maintenance of sperm quality. OBJECTIVE: To evaluate the use of different concentrations of glycosaminoglycans (GAGs) from the skin of Nile tilapia as a supplement in two cryogenic media for tambaqui semen. MATERIALS AND METHODS: Tambaqui males received a single dose of pituitary carp extract. The semen was collected for pool analysis and, later, cryopreserved in liquid nitrogen. The pools were diluted and frozen in a solution containing fish-specific powdered coconut water (ACP-104) and 10% DMSO or 5% Glucose and 10% DMSO and supplemented with different concentrations of GAGs. The controls had no GAGs addition. After 45 days, the samples were thawed by immersion in a water bath and evaluated for membrane and DNA integrity, morphology and sperm kinetics. RESULTS: The parameters of linearity (LIN), straightness (STR) and DNA integrity of sperm frozen in 5% Glucose showed better results than ACP-104. For membrane integrity, concentrations of 0 and 1.0 mg/mL were better than 5 mg/mL. Semen motility in 5% Glucose showed superior results at concentrations lower than 5 mg/mL of GAGs. For VCL and VAP, in ACP-104, 3.0 mg/mL exceeded the other treatments. In 5% Glucose, for VCL, 4.0 mg/mL showed the lowest results compared to concentrations of <3.5 mg/mL and, for VAP, it also differed from 4.5 mg/mL CONCLUSION: Therefore, the skin of Nile tilapia has GAGs, in low concentrations, capable of improving the post-thawed sperm quality of tambaqui, especially in 5% Glucose medium.


Asunto(s)
Preservación de la Fertilidad , Preservación de Semen , Tilapia , Animales , Criopreservación/métodos , Criopreservación/veterinaria , Crioprotectores/farmacología , Glicosaminoglicanos/farmacología , Masculino , Preservación de Semen/métodos , Preservación de Semen/veterinaria , Espermatozoides
5.
Braz J Med Biol Res ; 52(2): e7637, 2019 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-30698225

RESUMEN

Non-diabetic individuals use hormones like insulin to improve muscle strength and performance. However, as insulin also leads the liver and the adipose tissue to an anabolic state, the purpose of this study was to investigate the effects of insulin on liver metabolism in trained non-diabetic Swiss mice. The mice were divided into four groups: sedentary treated with saline (SS) or insulin (SI) and trained treated with saline (TS) or insulin (TI). Training was made in a vertical stair, at 90% of the maximum load, three times per week. Insulin (0.3 U/kg body weight) or saline were given intraperitoneally five times per week. After eight weeks, tissue and blood were collected and in situ liver perfusion with glycerol+lactate or alanine+glutamine (4 mM each) was carried out. The trained animals increased their muscle strength (+100%) and decreased body weight gain (-11%), subcutaneous fat (-42%), mesenteric fat (-45%), and peritoneal adipocyte size (-33%) compared with the sedentary groups. Insulin prevented the adipose effects of training (TI). The gastrocnemius muscle had greater density of muscle fibers (+60%) and less connective tissue in the trained groups. Liver glycogen was increased by insulin (SI +40% and TI +117%), as well as liver basal glucose release (TI +40%). Lactate and pyruvate release were reduced to a half by training. The greater gluconeogenesis from alanine+glutamine induced by training (TS +50%) was reversed by insulin (TI). Insulin administration had no additional effect on muscle strength and reversed some of the lipolytic and gluconeogenic effects of the resistance training. Therefore, insulin administration does not complement training in improving liver glucose metabolism.


Asunto(s)
Glucosa/administración & dosificación , Glucosa/efectos adversos , Hígado/efectos de los fármacos , Fuerza Muscular , Condicionamiento Físico Animal , Animales , Prueba de Esfuerzo , Glucosa/metabolismo , Hígado/metabolismo , Masculino , Ratones , Condicionamiento Físico Animal/fisiología , Entrenamiento de Fuerza
6.
Braz. j. med. biol. res ; 52(2): e7637, 2019. tab, graf
Artículo en Inglés | LILACS | ID: biblio-984028

RESUMEN

Non-diabetic individuals use hormones like insulin to improve muscle strength and performance. However, as insulin also leads the liver and the adipose tissue to an anabolic state, the purpose of this study was to investigate the effects of insulin on liver metabolism in trained non-diabetic Swiss mice. The mice were divided into four groups: sedentary treated with saline (SS) or insulin (SI) and trained treated with saline (TS) or insulin (TI). Training was made in a vertical stair, at 90% of the maximum load, three times per week. Insulin (0.3 U/kg body weight) or saline were given intraperitoneally five times per week. After eight weeks, tissue and blood were collected and in situ liver perfusion with glycerol+lactate or alanine+glutamine (4 mM each) was carried out. The trained animals increased their muscle strength (+100%) and decreased body weight gain (-11%), subcutaneous fat (-42%), mesenteric fat (-45%), and peritoneal adipocyte size (-33%) compared with the sedentary groups. Insulin prevented the adipose effects of training (TI). The gastrocnemius muscle had greater density of muscle fibers (+60%) and less connective tissue in the trained groups. Liver glycogen was increased by insulin (SI +40% and TI +117%), as well as liver basal glucose release (TI +40%). Lactate and pyruvate release were reduced to a half by training. The greater gluconeogenesis from alanine+glutamine induced by training (TS +50%) was reversed by insulin (TI). Insulin administration had no additional effect on muscle strength and reversed some of the lipolytic and gluconeogenic effects of the resistance training. Therefore, insulin administration does not complement training in improving liver glucose metabolism.


Asunto(s)
Animales , Masculino , Conejos , Condicionamiento Físico Animal/fisiología , Fuerza Muscular , Glucosa/administración & dosificación , Glucosa/efectos adversos , Hígado/efectos de los fármacos , Prueba de Esfuerzo , Entrenamiento de Fuerza , Glucosa/metabolismo , Hígado/metabolismo
7.
Braz. j. med. biol. res ; 42(6): 574-581, June 2009. graf, tab
Artículo en Inglés | LILACS | ID: lil-512757

RESUMEN

The pharmacokinetics of some β-blockers are altered by cardiopulmonary bypass (CPB). The objective of this study was to compare the effect of coronary artery bypass graft (CABG) surgery employing CPB on the pharmacokinetics of propranolol and atenolol. We studied patients receiving oral propranolol with doses ranging from 80 to 240 mg (N = 11) or atenolol with doses ranging from 25 to 100 mg (N = 8) in the pre- and postoperative period of CABG with moderately hypothermic CPB (32°C). On the day before and on the first day after surgery, blood samples were collected before β-blocker administration and every 2 h thereafter. Plasma levels were determined using high-performance liquid chromatography and data were treated by pharmacokinetics-modelling. Statistical analysis was performed using ANOVA or the Friedman test, as appropriate, and P < 0.05 was considered to be significant. A prolongation of propranolol biological half-life from 5.41 ± 0.75 to 11.46 ± 1.66 h (P = 0.0028) and an increase in propranolol volume of distribution from 8.70 ± 2.83 to 19.33 ± 6.52 L/kg (P = 0.0032) were observed after CABG with CPB. No significant changes were observed in either atenolol biological half-life (from 11.20 ± 1.60 to 11.44 ± 2.89 h) or atenolol volume of distribution (from 2.90 ± 0.36 to 3.83 ± 0.72 L/kg). Total clearance was not changed by surgery. These CPB-induced alterations in propranolol pharmacokinetics may promote unexpected long-lasting effects in the postoperative period while the effects of atenolol were not modified by CPB surgery.


Asunto(s)
Femenino , Humanos , Masculino , Persona de Mediana Edad , Antagonistas Adrenérgicos beta/farmacocinética , Atenolol/farmacocinética , Puente Cardiopulmonar , Puente de Arteria Coronaria , Enfermedad Coronaria/cirugía , Propranolol/farmacocinética , Antagonistas Adrenérgicos beta/sangre , Atenolol/sangre , Cromatografía Líquida de Alta Presión , Enfermedad Coronaria/sangre , Periodo Posoperatorio , Periodo Preoperatorio , Propranolol/sangre
8.
Braz J Med Biol Res ; 42(6): 574-81, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19448909

RESUMEN

The pharmacokinetics of some beta-blockers are altered by cardiopulmonary bypass (CPB). The objective of this study was to compare the effect of coronary artery bypass graft (CABG) surgery employing CPB on the pharmacokinetics of propranolol and atenolol. We studied patients receiving oral propranolol with doses ranging from 80 to 240 mg (N = 11) or atenolol with doses ranging from 25 to 100 mg (N = 8) in the pre- and postoperative period of CABG with moderately hypothermic CPB (32 degrees C). On the day before and on the first day after surgery, blood samples were collected before beta-blocker administration and every 2 h thereafter. Plasma levels were determined using high-performance liquid chromatography and data were treated by pharmacokinetics-modelling. Statistical analysis was performed using ANOVA or the Friedman test, as appropriate, and P < 0.05 was considered to be significant. A prolongation of propranolol biological half-life from 5.41 +/- 0.75 to 11.46 +/- 1.66 h (P = 0.0028) and an increase in propranolol volume of distribution from 8.70 +/- 2.83 to 19.33 +/- 6.52 L/kg (P = 0.0032) were observed after CABG with CPB. No significant changes were observed in either atenolol biological half-life (from 11.20 +/- 1.60 to 11.44 +/- 2.89 h) or atenolol volume of distribution (from 2.90 +/- 0.36 to 3.83 +/- 0.72 L/kg). Total clearance was not changed by surgery. These CPB-induced alterations in propranolol pharmacokinetics may promote unexpected long-lasting effects in the postoperative period while the effects of atenolol were not modified by CPB surgery.


Asunto(s)
Antagonistas Adrenérgicos beta/farmacocinética , Atenolol/farmacocinética , Puente Cardiopulmonar , Puente de Arteria Coronaria , Enfermedad Coronaria/cirugía , Propranolol/farmacocinética , Antagonistas Adrenérgicos beta/sangre , Atenolol/sangre , Cromatografía Líquida de Alta Presión , Enfermedad Coronaria/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Periodo Preoperatorio , Propranolol/sangre
9.
Braz J Med Biol Res ; 38(5): 713-21, 2005 05.
Artículo en Inglés | MEDLINE | ID: mdl-15917952

RESUMEN

The pharmacokinetics of propranolol may be altered by hypothermic cardiopulmonary bypass (CPB), resulting in unpredictable postoperative hemodynamic responses to usual doses. The objective of the present study was to investigate the pharmacokinetics of propranolol in patients undergoing coronary artery bypass grafting (CABG) by CPB under moderate hypothermia. We evaluated 11 patients, 4 women and 7 men (mean age 57 +/- 8 years, mean weight 75.4 +/- 11.9 kg and mean body surface area 1.83 +/- 0.19 m(2)), receiving propranolol before surgery (80-240 mg a day) and postoperatively (10 mg a day). Plasma propranolol levels were measured before and after CPB by high-performance liquid chromatography. Pharmacokinetic Solutions 2.0 software was used to estimate the pharmacokinetic parameters after administration of the drug pre- and postoperatively. There was an increase of biological half-life from 4.5 (95% CI = 3.9-6.9) to 10.6 h (95% CI = 8.2-14.7; P < 0.01) and an increase in volume of distribution from 4.9 (95% CI = 3.2-14.3) to 8.3 l/kg (95% CI = 6.5-32.1; P < 0.05), while total clearance remained unchanged 9.2 (95% CI = 7.7-24.6) vs 10.7 ml min(-1) kg(-1) (95% CI = 7.7-26.6; NS) after surgery. In conclusion, increases in drug distribution could be explained in part by hemodilution during CPB. On the other hand, the increase of biological half-life can be attributed to changes in hepatic metabolism induced by CPB under moderate hypothermia. These alterations in the pharmacokinetics of propranolol after CABG with hypothermic CPB might induce a greater myocardial depression in response to propranolol than would be expected with an equivalent dose during the postoperative period.


Asunto(s)
Antagonistas Adrenérgicos beta/farmacocinética , Puente Cardiopulmonar , Puente de Arteria Coronaria , Enfermedad Coronaria/sangre , Propranolol/farmacocinética , Antagonistas Adrenérgicos beta/sangre , Adulto , Anciano , Cromatografía Líquida de Alta Presión , Enfermedad Coronaria/cirugía , Femenino , Humanos , Hipotermia Inducida , Masculino , Persona de Mediana Edad , Periodo Posoperatorio , Propranolol/sangre
10.
Braz. j. med. biol. res ; 38(5): 713-721, May 2005. tab, graf
Artículo en Inglés | LILACS | ID: lil-400950

RESUMEN

The pharmacokinetics of propranolol may be altered by hypothermic cardiopulmonary bypass (CPB), resulting in unpredictable postoperative hemodynamic responses to usual doses. The objective of the present study was to investigate the pharmacokinetics of propranolol in patients undergoing coronary artery bypass grafting (CABG) by CPB under moderate hypothermia. We evaluated 11 patients, 4 women and 7 men (mean age 57 ± 8 years, mean weight 75.4 ± 11.9 kg and mean body surface area 1.83 ± 0.19 m²), receiving propranolol before surgery (80-240 mg a day) and postoperatively (10 mg a day). Plasma propranolol levels were measured before and after CPB by high-performance liquid chromatography. Pharmacokinetic Solutions 2.0 software was used to estimate the pharmacokinetic parameters after administration of the drug pre- and postoperatively. There was an increase of biological half-life from 4.5 (95 percent CI = 3.9-6.9) to 10.6 h (95 percent CI = 8.2-14.7; P < 0.01) and an increase in volume of distribution from 4.9 (95 percent CI = 3.2-14.3) to 8.3 l/kg (95 percent CI = 6.5-32.1; P < 0.05), while total clearance remained unchanged 9.2 (95 percent CI = 7.7-24.6) vs 10.7 ml min-1 kg-1 (95 percent CI = 7.7-26.6; NS) after surgery. In conclusion, increases in drug distribution could be explained in part by hemodilution during CPB. On the other hand, the increase of biological half-life can be attributed to changes in hepatic metabolism induced by CPB under moderate hypothermia. These alterations in the pharmacokinetics of propranolol after CABG with hypothermic CPB might induce a greater myocardial depression in response to propranolol than would be expected with an equivalent dose during the postoperative period.


Asunto(s)
Adulto , Persona de Mediana Edad , Humanos , Masculino , Femenino , Antagonistas Adrenérgicos beta/farmacocinética , Puente Cardiopulmonar , Puente de Arteria Coronaria , Enfermedad Coronaria/cirugía , Propranolol/farmacocinética , Cromatografía Líquida de Alta Presión , Hipotermia , Periodo Posoperatorio
11.
Braz. j. med. biol. res ; 33(5): 509-14, May 2000. graf
Artículo en Inglés | LILACS | ID: lil-260244

RESUMEN

We describe a new simple, selective and sensitive micromethod based on HPLC and fluorescence detection to measure debrisoquine (D) and 4-hydroxydebrisoquine (4-OHD) in urine for the investigation of xenobiotic metabolism by debrisoquine hydroxylase (CYP2D6). Four hundred µl of urine was required for the analysis of D and 4-OHD. Peaks were eluted at 8.3 min (4-OHD), 14.0 min (D) and 16.6 min for the internal standard, metoprolol (20 µg/ml). The 5-µm CN-reverse-phase column (Shimpack, 250 x 4.6 mm) was eluted with a mobile phase consisting of 0.25 M acetate buffer, pH 5.0, and acetonitrile (9:1, v/v) at 0.7 ml/min with detection at lexcitation = 210 nm and lemission = 290 nm. The method, validated on the basis of measurements of spiked urine, presented 3 ng/ml (D) and 6 ng/ml (4-OHD) sensitivity, 390-6240 ng/ml (D) and 750-12000 ng/ml (4-OHD) linearity, and 5.7/8.2 percent (D) and 5.3/8.2 percent (4-OHD) intra/interassay precision. The method was validated using urine of a healthy Caucasian volunteer who received one 10-mg tablet of Declinax®, po, in the morning after an overnight fast. Urine samples (diuresis of 4 or 6 h) were collected from zero to 24 h. The urinary excretion of D and 4-OHD, Fel (0-24 h), i.e., fraction of dose administered and excreted into urine, was 6.4 percent and 31.9 percent, respectively. The hydroxylation capacity index reported as metabolic ratio was 0.18 (D/4-OHD) for the person investigated and can be compared to reference limits of < 12.5 for poor metabolizers (PM) and < 12.5 for extensive metabolizers (EM). In parallel, the recovery ratio (RR), another hydroxylation capacity index, was 0.85 (4-OHD: SD + 4-OHD) versus reference limits of RR < 0.12 for PM and RR > 0.12 for EM. The healthy volunteer was considered to be an extensive metabolizer on the basis of the debrisoquine test.


Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Cromatografía Líquida de Alta Presión/métodos , Citocromo P-450 CYP2D6/metabolismo , Debrisoquina/orina , Intervalos de Confianza , Debrisoquina/metabolismo , Población Blanca , Fluorometría/métodos , Hidroxilación , Fenotipo , Sensibilidad y Especificidad
12.
J Chromatogr B Biomed Sci Appl ; 738(1): 27-37, 2000 Jan 28.
Artículo en Inglés | MEDLINE | ID: mdl-10778923

RESUMEN

Direct enantioselective separation on chiral stationary phases and indirect separation based on the formation of diastereomeric derivatives were developed and compared for the HPLC analysis of R(+) and S(-)-metoprolol in human plasma. Plasma samples prepared using solid-phase extraction columns or liquid-liquid extraction were directly analyzed on a Chiralpack AD or on a Chiralcel OD-H columns, respectively. S-(-)-menthyl choroformate was also used to yield diastereomeric derivatives resolved on a RP-8 column. The methods were employed to determine plasma concentrations of metoprolol enantiomers in a pharmacokinetic study of single dose administration of racemic metoprolol to a healthy Caucasian volunteer phenotyped as extensive metabolizer of debrisoquine. The correlation coefficients among enantioselective metoprolol plasma concentrations (5-223 ng/ml) obtained by the three methods were equal or higher than 0.99. The direct method that employed the chiral column Chiralpak AD may be considered the most sensitive, although the three methods demonstrated interchangeable use in the pharmacokinetic investigation.


Asunto(s)
Antagonistas Adrenérgicos beta/sangre , Antagonistas Adrenérgicos beta/farmacocinética , Cromatografía Líquida de Alta Presión/métodos , Metoprolol/sangre , Metoprolol/farmacocinética , Humanos , Cinética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Estereoisomerismo
13.
Braz J Med Biol Res ; 33(5): 509-14, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10775881

RESUMEN

We describe a new simple, selective and sensitive micromethod based on HPLC and fluorescence detection to measure debrisoquine (D) and 4-hydroxydebrisoquine (4-OHD) in urine for the investigation of xenobiotic metabolism by debrisoquine hydroxylase (CYP2D6). Four hundred microl of urine was required for the analysis of D and 4-OHD. Peaks were eluted at 8.3 min (4-OHD), 14.0 min (D) and 16.6 min for the internal standard, metoprolol (20 microg/ml). The 5-microm CN-reverse-phase column (Shimpack, 250 x 4.6 mm) was eluted with a mobile phase consisting of 0.25 M acetate buffer, pH 5.0, and acetonitrile (9:1, v/v) at 0.7 ml/min with detection at lambdaexcitation = 210 nm and lambdaemission = 290 nm. The method, validated on the basis of measurements of spiked urine, presented 3 ng/ml (D) and 6 ng/ml (4-OHD) sensitivity, 390-6240 ng/ml (D) and 750-12000 ng/ml (4-OHD) linearity, and 5.7/8.2% (D) and 5.3/8.2% (4-OHD) intra/interassay precision. The method was validated using urine of a healthy Caucasian volunteer who received one 10-mg tablet of Declinax(R), po, in the morning after an overnight fast. Urine samples (diuresis of 4 or 6 h) were collected from zero to 24 h. The urinary excretion of D and 4-OHD, Fel (0-24 h), i.e., fraction of dose administered and excreted into urine, was 6.4% and 31.9%, respectively. The hydroxylation capacity index reported as metabolic ratio was 0.18 (D/4-OHD) for the person investigated and can be compared to reference limits of >12.5 for poor metabolizers (PM) and <12.5 for extensive metabolizers (EM). In parallel, the recovery ratio (RR), another hydroxylation capacity index, was 0.85 (4-OHD: SigmaD + 4-OHD) versus reference limits of RR <0.12 for PM and RR >0. 12 for EM. The healthy volunteer was considered to be an extensive metabolizer on the basis of the debrisoquine test.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Citocromo P-450 CYP2D6/metabolismo , Debrisoquina/análogos & derivados , Debrisoquina/orina , Femenino , Fluorometría/métodos , Humanos , Hidroxilación , Persona de Mediana Edad , Fenotipo , Sensibilidad y Especificidad , Xenobióticos/metabolismo
14.
Braz J Med Biol Res ; 33(2): 199-204, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10657059

RESUMEN

R,S-sotalol, a ss-blocker drug with class III antiarrhythmic properties, is prescribed to patients with ventricular, atrial and supraventricular arrhythmias. A simple and sensitive method based on HPLC-fluorescence is described for the quantification of R,S-sotalol racemate in 500 microl of plasma. R,S-sotalol and its internal standard (atenolol) were eluted after 5.9 and 8.5 min, respectively, from a 4-micron C18 reverse-phase column using a mobile phase consisting of 80 mM KH2PO4, pH 4.6, and acetonitrile (95:5, v/v) at a flow rate of 0.5 ml/min with detection at lambdaex = 235 nm and lambdaem = 310 nm, respectively. This method, validated on the basis of R,S-sotalol measurements in spiked blank plasma, presented 20 ng/ml sensitivity, 20-10,000 ng/ml linearity, and 2.9 and 4.8% intra- and interassay precision, respectively. Plasma sotalol concentrations were determined by applying this method to investigate five high-risk patients with atrial fibrillation admitted to the Emergency Service of the Medical School Hospital, who received sotalol, 160 mg po, as loading dose. Blood samples were collected from a peripheral vein at zero, 0.5, 1.0, 1.5, 2.0, 3.0, 4. 0, 6.0, 8.0, 12.0 and 24.0 h after drug administration. A two-compartment open model was applied. Data obtained, expressed as mean, were: C MAX = 1230 ng/ml, T MAX = 1.8 h, AUC T = 10645 ng h-1 ml-1, Kab = 1.23 h-1, alpha = 0.95 h-1, ss = 0.09 h-1, t((1/2))ss = 7.8 h, ClT/F = 3.94 ml min-1 kg-1, and Vd/F = 2.53 l/kg. A good systemic availability and a fast absorption were obtained. Drug distribution was reduced to the same extent in terms of total body clearance when patients and healthy volunteers were compared, and consequently elimination half-life remained unchanged. Thus, the method described in the present study is useful for therapeutic drug monitoring purposes, pharmacokinetic investigation and pharmacokinetic-pharmacodynamic sotalol studies in patients with tachyarrhythmias.


Asunto(s)
Antiarrítmicos/sangre , Fibrilación Atrial/sangre , Cromatografía Líquida de Alta Presión/métodos , Sotalol/sangre , Antiarrítmicos/farmacocinética , Antiarrítmicos/uso terapéutico , Área Bajo la Curva , Fibrilación Atrial/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Sotalol/farmacocinética , Sotalol/uso terapéutico
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