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1.
Horm Metab Res ; 48(12): 814-821, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27813051

RESUMO

Salivary cortisol has been used to monitor hydrocortisone replacement in patients with Addison's disease (AD). Since salivary cortisol is metabolised to salivary cortisone, it may be an adjunctive analyte to assess adequacy of hydrocortisone replacement in patients with AD. We aimed to characterise the exposure of salivary cortisol and cortisone in patients and healthy controls. We measured salivary cortisol and cortisone by liquid chromatography-tandem mass spectrometry and constructed a day curve (08:00 until 24:00 h) with 16 time points in 25 AD patients taking their usual hydrocortisone dose and in 26 healthy controls. The median (interquartile range) area under the curve (AUC) for cortisol was not different for patients, compared with controls [55.63 (32.91-151.07) nmol*min*l-1 vs. 37.49 (27.41-52.00) nmol*min*l-1; p=0.098, respectively], whereas the peak cortisol Cmax was higher in patients [32.61 (5.75-146.19) nmol/l vs. 8.96 (6.96-12.23) nmol/l; p=0.013], compared with controls. The AUC for cortisone [23.65 (6.10-54.76) nmol*min*l-1 vs. 227.73 (200.10-280.52) nmol*min*l-1; p≤ 0.001, respectively], and peak cortisone Cmax was lower in patients than in controls [11.11 (2.91-35.85) nmol/l vs. 33.12 (25.97-39.95) nmol/l; p=0.002]. The AUC for salivary cortisol and salivary cortisone were not correlated with any measures of hydrocortisone dose. The time-course and AUC of salivary cortisol were similar between Addison's patients and healthy controls. Patients had substantially lower salivary cortisone AUC, compared to healthy controls. Salivary cortisol AUC and pharmacokinetics were not related to hydrocortisone dose and thus are not likely useful markers for the adequacy of hydrocortisone replacement.


Assuntos
Doença de Addison/tratamento farmacológico , Cortisona/metabolismo , Terapia de Reposição Hormonal , Hidrocortisona/metabolismo , Hidrocortisona/uso terapêutico , Saliva/metabolismo , Adulto , Biomarcadores/metabolismo , Estudos de Casos e Controles , Cortisona/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto Jovem
2.
J Pharm Sci ; 104(10): 3578-86, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26150050

RESUMO

The combined clearance of endogenous 6ß-hydroxycortisol and 6ß-hydroxycortisone is suggested biomarker for in vivo cytochrome P450 3A (CYP3A) activity. We aimed to determine whether the combined clearance of these two markers together with information of biopharmaceutics classification system (BCS) of drugs could be used to predict CYP3A-mediated metabolism of immunosuppressants. The BCS of drug formulations were determined based on the solubility and permeability. Sixty-seven healthy subjects were divided into three groups and group 1 (n = 23), 2 (n = 22), and 3 (n = 22) received oral single dose of cyclosporine, tacrolimus, and sirolimus, respectively. Blood and urine samples were gathered at various times. The combined clearance of 6ß-hydroxycortisol and 6ß-hydroxycortisone correlated significantly with cyclosporine pharmacokinetics (p < 0.001) after oral dose of a BCS 1 formulation, whereas no relationships were seen after administration of tacrolimus and sirolimus formulations, both of which belonged to BCS 2. Regarding the biopharmaceutical characteristics, the endogenous CYP3A biomarker explains 74.5% of variability in oral cyclosporine clearance between individuals.


Assuntos
Cortisona/análogos & derivados , Citocromo P-450 CYP3A/metabolismo , Hidrocortisona/análogos & derivados , Imunossupressores/metabolismo , Biomarcadores/análise , Biofarmácia , Química Farmacêutica , Cortisona/análise , Cortisona/farmacocinética , Ciclosporina/farmacocinética , Citocromo P-450 CYP3A/genética , Feminino , Genótipo , Humanos , Hidrocortisona/análise , Hidrocortisona/farmacocinética , Técnicas In Vitro , Fígado/metabolismo , Masculino , Valor Preditivo dos Testes , Sirolimo/farmacocinética , Tacrolimo/farmacocinética , Adulto Jovem
3.
J Biomed Biotechnol ; 2012: 856324, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23258958

RESUMO

The purpose of this paper is to study pharmacokinetics of cortisone (E) and its metabolite cortisol (F) in rats after administration of glycyrrhetinic acid (GA) and cortisone. Healthy male SD rats were randomized to be given 20 mg/kg E or E combined with 10 mg/kg GA. Blood samples were collected at 5, 10, 20, 40, 60, 90, 120, 150, 180, and 240 min after administration. The serum concentrations of E and F were determined by HLPC and pharmacokinetic parameters were calculated using DASver2.0 software. The parameters of AUC((0-t)), AUC((0-∞)), and C(max) for E in the group of E + GA were significantly higher than those in the group of E (P < 0.01); the half-time (t(1/2ß)) was extended compared to E (P < 0.05) and CL/F was dropped obviously (P < 0.01). The rise in AUC((0-t)), AUC((0-∞)), and C(max) for cortisol in the group of E + GA was significantly compared to the group of E (P < 0.01). CL/F was lower than E (P < 0.01) and the half-time (t(1/2ß)) was slightly extended. In this study, we find that GA restrains the metabolism of E and F and thus increases AUC, t(1/2ß), and C(max) of E and F, which may be related to its inhibition effect on 11ß-hydroxysteroid dehydrogenase (11ß-HSD).


Assuntos
Cortisona/farmacocinética , Ácido Glicirretínico/farmacologia , Hidrocortisona/metabolismo , Hidrocortisona/farmacocinética , Animais , Cromatografia Líquida de Alta Pressão , Ácido Glicirretínico/administração & dosagem , Masculino , Ratos , Ratos Sprague-Dawley , Padrões de Referência , Reprodutibilidade dos Testes , Fatores de Tempo
4.
Gynecol Endocrinol ; 27(10): 794-9, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21736538

RESUMO

Menopause is associated with central obesity, dyslipidemia, hypertension and insulin resistance, which are also shown in the patients with excess of glucocorticoids. However, the interaction of hypothalamic-pituitary-adrenal (HPA) axis activity and menopause has not been fully understood. In this study, 55 healthy non-obese women were recruited, and then divided into two groups, premenopausal group (n = 24) and postmenopausal group (n = 31). HPA axis function was evaluated by using dexamethasone suppression test (DST; 0.25 mg), and adrenocorticotrophic hormone (ACTH)-stimulation test. Moreover, 25 mg cortisone acetate test was applied to evaluate the hepatic 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) activity. We found that hepatic 11ß-HSD1 activity and adrenal response to ACTH were increased in the postmenopausal group compared with the premenopausal group, whereas the negative feedback effect of dexamethasone did not show significant difference between pre- and postmenopausal women. These findings suggest that the adrenal sensitivity to ACTH and hepatic 11ß-HSD1 activity are increased. The increased cortisol conversion and/or synthesis may be contributed to the dysmetabolic features in the postmenopausal women.


Assuntos
Glândulas Suprarrenais/fisiologia , Hormônio Adrenocorticotrópico , Fígado/enzimologia , Menopausa/fisiologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Glândulas Suprarrenais/efeitos dos fármacos , Adulto , Idoso , Biotransformação , Índice de Massa Corporal , China , Cortisona/análogos & derivados , Cortisona/farmacocinética , Dexametasona , Retroalimentação Fisiológica/efeitos dos fármacos , Feminino , Glucocorticoides , Humanos , Hidrocortisona/sangue , Sistema Hipotálamo-Hipofisário/efeitos dos fármacos , Sistema Hipotálamo-Hipofisário/fisiologia , Menopausa/sangue , Pessoa de Meia-Idade , Sistema Hipófise-Suprarrenal/efeitos dos fármacos , Sistema Hipófise-Suprarrenal/fisiologia
5.
Clin Endocrinol (Oxf) ; 74(1): 30-6, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21054475

RESUMO

OBJECTIVE: Corticosteroid-binding globulin (CBG) is the principal carrier for cortisol in the circulation. Variations in CBG-binding capacity are predicted to alter total serum cortisol disposition, but free serum cortisol is believed to be unaffected. Unbound cortisol pharmacokinetics (PK) have not been studied in the context of CBG changes. We aimed to assess the regulation of cortisol PK by CBG. DESIGN AND SUBJECTS: Women on oestrogens [oral contraceptive pill, (OCP)], patients homozygous for a nonfunctioning CBG variant (CBG null) and healthy controls (HV) were studied before and after IV and oral administration of hydrocortisone 20 mg. MEASUREMENTS: PK parameters were studied for total serum cortisol (SerF), free serum cortisol (FreeF) and cortisone (FreeE), and salivary cortisol (SalF) and cortisone (SalE): area under the curve (AUC), clearance (CL), half-life and volume of distribution (V(d)). RESULTS: Following IV hydrocortisone, AUC and half-life of SerF were significantly higher in the OCP group and lower in the CBG null. SerF CL and V(d) were significantly lower in the OCP group and increased in the CBG null, compared to HV. PK parameters for FreeF and the salivary biomarkers were not different between the CBG null and HV, although OCP patients still had higher AUC compared to HV and prolonged half-life. These findings were confirmed following oral hydrocortisone, but concentration-time profiles were highly heterogeneous and SalF interpretation was problematic because of oral contamination. CONCLUSIONS: We have demonstrated that CBG has a distinct effect on cortisol PK. When CBG binding is disrupted, FreeF retains normal PK characteristics, although CBG null patients lack a CBG-bound pool of readily releasable cortisol. Women on oestrogens may have altered free serum cortisol kinetics and thus may be potentially overexposed to glucocorticoids.


Assuntos
Hidrocortisona/farmacocinética , Transcortina/metabolismo , Adulto , Anticoncepcionais Orais , Cortisona/sangue , Cortisona/farmacocinética , Feminino , Humanos , Hidrocortisona/sangue , Imunoensaio , Pessoa de Meia-Idade , Saliva/química , Transcortina/genética , Adulto Jovem
6.
J Clin Endocrinol Metab ; 95(10): 4696-702, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20631029

RESUMO

CONTEXT: Lipophilic plasma glucocorticoids are thought to gain rapid access to intracellular compartments in adipose tissue. In other organs, transport can be regulated in a steroid- and tissue-specific manner. Moreover, 11ß-hydroxysteroid dehydrogenase type 1 (11ßHSD1) generates additional cortisol within adipose. AIM: The aim was to measure the rate of exchange of cortisol between plasma and adipose for comparison with rates of intracellular cortisol generation by 11ßHSD1. PARTICIPANTS AND INTERVENTIONS: With ethical approval, otherwise healthy females (n = 6) undergoing hysterectomy for benign indications were infused with tracer 9,11,12,12-[(2)H](4)cortisol (d4-cortisol). Adipose biopsies and peripheral venous samples were obtained during surgery after 3.9-5.5 h of infusion. Glucocorticoids were quantified using liquid chromatography tandem mass spectrometry. RESULTS: In plasma, d4-cortisol concentrations and appearance rates of cortisol and d3-cortisol (reflecting 11ßHSD1 activity) did not change during surgery. In both omental and sc adipose, cortisol concentrations were lower than in plasma, consistent with differences in corticosteroid binding globulin, and enrichment with d4-cortisol was low (sc, 7.2 ± 0.6%; omental, 7.4 ± 0.7%; vs. plasma, 15.5 ± 1.0%). The rate of accumulation of d4-cortisol in adipose depots was 0.5 ± 0.1 (sc) and 0.4 ± 0.1 (omental) nmol/kg · h, and the proportion of intraadipose cortisol replaced each hour only 10.7 ± 1.0 and 10.4 ± 0.7%, respectively. The contribution of 11ßHSD1 to this turnover could not be quantified because very little substrate d3-cortisone accumulated in adipose during infusion. CONCLUSIONS: Slow turnover of the adipose glucocorticoid pool suggests that rapid acute fluctuations in circulating cortisol are not reflected in adipose, so that 11ßHSD1 activity (previously estimated to generate 9 nmol cortisol/kg · h in sc adipose) may play a relatively important role in modulating activation of glucocorticoid receptors.


Assuntos
Tecido Adiposo/metabolismo , Glucocorticoides/farmacocinética , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Tecido Adiposo/patologia , Adulto , Cortisona/farmacocinética , Feminino , Glucocorticoides/sangue , Glucocorticoides/metabolismo , Humanos , Hidrocortisona/sangue , Hidrocortisona/metabolismo , Hidrocortisona/farmacocinética , Histerectomia , Período Intraoperatório , Pessoa de Meia-Idade , Omento/metabolismo , Omento/patologia , Omento/cirurgia , Gordura Subcutânea/metabolismo , Gordura Subcutânea/patologia , Fatores de Tempo
7.
J Steroid Biochem Mol Biol ; 117(4-5): 146-51, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19744560

RESUMO

An intensive and systematic investigation had been carried out on the Delta(1)-dehydrogenation of cortisone acetate (CA) to prednisone acetate (PA) by Arthrobacter simplex TCCC 11037 in the presence of native and modified beta-cyclodextrins (beta-CDs). The biotransformation was improved through the formation of the host-guest inclusion complex between CA and CDs in aqueous solution. The inclusion complexes of CDs with CA were investigated by means of phase solubility, 2D NMR spectroscopy and differential scanning calorimetry (DSC). The structural difference of CDs resulted in the stoichiometric differences between the complexes, the RM-beta-CD-CA, SBE-beta-CD-CA, HP-beta-CD-CA complexes were 1:1 whereas beta-CD-CA gave both 1:1 and 2:1 complexes, of which the 2:1 complex decreased the soluble CA concentration and inhibited the dissociation of beta-CD-CA in aqueous solution. The increase in solubility of CA was in the order of RM-beta-CD>SBE-beta-CD>HP-beta-CD>beta-CD. RM-beta-CD-CA, SBE-beta-CD-CA and HP-beta-CD-CA exhibited the higher biotransformation rate in comparison with native beta-CD. And the solubilization of CDs for CA in aqueous medium plays a key role in the biotransformation process. The article focuses on the various factors influencing the substrate water solubility, complex stability and biotransformation of CA through the addition of CDs in order to solve many problems associated with the process of drug delivery and biotransformation of different novel steroids.


Assuntos
Cortisona/análogos & derivados , Arthrobacter/metabolismo , Biocatálise , Biotransformação , Varredura Diferencial de Calorimetria , Cortisona/farmacocinética , Espectroscopia de Ressonância Magnética , Solubilidade
8.
J Clin Endocrinol Metab ; 92(5): 1848-56, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17327378

RESUMO

CONTEXT: In animals, peroxisome proliferator-activated receptor-alpha (PPARalpha) and PPARgamma agonists down-regulate 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) mRNA and activity in liver and adipose tissue, respectively, and PPARgamma agonists reduce ACTH secretion from corticotrope cells. OBJECTIVE: Our objective was to test whether PPAR agonists alter cortisol secretion and peripheral regeneration by 11beta-HSD1 in humans and whether reduced cortisol action contributes to metabolic effects of PPARgamma agonists. DESIGN AND SETTING: Three randomized placebo-controlled crossover studies were conducted at a clinical research facility. PATIENTS AND PARTICIPANTS: Healthy men and patients with type 2 diabetes participated. INTERVENTIONS, OUTCOME MEASURES, AND RESULTS: In nine healthy men, 7 d of PPARalpha agonist (fenofibrate) or PPARgamma agonist (rosiglitazone) had no effect on cortisol secretion, hepatic cortisol generation after oral cortisone administration, or tracer kinetics during 9,11,12,12-[(2)H](4)-cortisol infusion, although rosiglitazone marginally reduced cortisol generation in sc adipose tissue measured by in vivo microdialysis. In 12 healthy men, 4-5 wk of rosiglitazone increased insulin sensitivity during insulin infusion but did not change 11beta-HSD1 mRNA or activity in sc adipose tissue, and insulin sensitization was unaffected by glucocorticoid blockade with a combination of metyrapone and RU38486. In 12 men with type 2 diabetes 12 wk of rosiglitazone reduced arteriovenous cortisone extraction across abdominal sc adipose tissue and reduced 11beta-HSD1 mRNA in sc adipose tissue but increased plasma cortisol concentrations. CONCLUSIONS: Neither PPARalpha nor PPARgamma agonists down-regulate 11beta-HSD1 or cortisol secretion acutely in humans. The early insulin-sensitizing effect of rosiglitazone is not dependent on reducing intracellular glucocorticoid concentrations. Reduced adipose 11beta-HSD1 expression and increased plasma cortisol during longer therapy with rosiglitazone probably reflect indirect effects, e.g. mediated by changes in body fat.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , PPAR alfa/agonistas , PPAR gama/agonistas , Gordura Subcutânea/enzimologia , Adulto , Idoso , Cortisona/farmacocinética , Estudos Cross-Over , Método Duplo-Cego , Inibidores Enzimáticos/farmacologia , Fenofibrato/uso terapêutico , Cromatografia Gasosa-Espectrometria de Massas , Antagonistas de Hormônios/farmacologia , Humanos , Hidrocortisona/sangue , Hidrocortisona/urina , Hipolipemiantes/uso terapêutico , Resistência à Insulina/fisiologia , Cinética , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/metabolismo , Masculino , Metirapona/farmacologia , Microdiálise , Pessoa de Meia-Idade , Mifepristona/farmacologia , Obesidade/enzimologia , Rosiglitazona , Gordura Subcutânea/efeitos dos fármacos , Tiazolidinedionas/uso terapêutico
9.
Yao Xue Xue Bao ; 38(5): 384-7, 2003 May.
Artigo em Chinês | MEDLINE | ID: mdl-12958846

RESUMO

AIM: To test the enhancing activity and the mechanism of oleyl pyroglutamate used as transdermal enhancer. METHODS: The penetration-enhancing effects of oleyl pyroglutamate, oleyl alcohol and oleic acid on the three drugs (caffeine, tinidazole and cortisone) were observed; the transdermal enhancing mechanism of oleyl pyroglutamate was studied with the attenuated total reflectance Fourier-transfer infrared spectroscopy(ATR-FTIR) of the human stratum corneum in vivo. RESULTS: The penetration-enhancing ratio of the three drugs was 7.9 fold, 41.8 fold and 2.8 fold, respectively. The absorptions at 2,800-2,950 cm-1 and 1,642-1,646 cm-1 (amide-I) in the ATR-FTIR spectrum of the stratum were found to be shifted differently following removal of the stratum corneum which was treated with oleyl pyroglutamate. CONCLUSION: Oleyl pyroglutamate showed better penetration-enhancing effect on the penetration of drugs. Its transdermal enhancing mechanism may be that oleyl pyroglutamate induced not only disordering of the stratum corneum lipid, but also change of the secondary structure of keratin.


Assuntos
Cafeína/farmacocinética , Ácido Pirrolidonocarboxílico/farmacologia , Absorção Cutânea/efeitos dos fármacos , Administração Cutânea , Adulto , Animais , Cafeína/administração & dosagem , Cortisona/administração & dosagem , Cortisona/farmacocinética , Álcoois Graxos/farmacologia , Humanos , Masculino , Camundongos , Ácido Oleico/farmacologia , Ácido Pirrolidonocarboxílico/análogos & derivados , Ácido Pirrolidonocarboxílico/química , Tinidazol/administração & dosagem , Tinidazol/farmacocinética
11.
Scand J Clin Lab Invest ; 61(4): 277-86, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11465341

RESUMO

Growth hormone (GH) replacement may inhibit 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) activity, resulting in diminished conversion of cortisone to cortisol. Moreover, GH replacement may lower bioavailability of hydrocortisone tablets. Therefore, substitution therapy with cortisone acetate could be disadvantageous during GH replacement. We conducted a randomized, placebo-controlled GH replacement (1 to 2 U GH/day) study during 6 months, followed by a 6-month open extension study (2U GH/day). Twelve men and 12 women with GH deficiency, of whom 17 received cortisone acetate (25 to 37.5 mg/day), participated. Eight patients were randomized to placebo initially. At baseline, after 6 and 12 months, urinary cortisol and cortisone metabolites were measured. No changes in urinary cortisol metabolites were observed after 6 months placebo (n=8). After 6 months GH the urinary (tetrahydrocortisol+allotetrahydrocortisol)/tetrahydrocortison ratio ((THF+alloTHF)/THE ratio) was unaltered in cortisone acetate treated patients (n = 17) and in patients with intact adrenal function (n = 7), whereas after 12 months GH the (THF + alloTHF)/THE ratio decreased only in cortisone acetate treated patients (1 dropout, n=9). Urinary THF and alloTHF were higher in cortisone acetate treated patients than in patients with intact adrenal function before GH and remained so after 12 months GH (p < 0.05 to p < 0.01). The sum of cortisol + cortisone metabolites did not change after GH in either group. The urinary free cortisol/free cortisone ratio, presumably reflecting renal 11betaHSD2 activity, tended to decrease in cortisone acetate treated patients (p<0.07 and p<0.05 after 6 and 12 months GH, respectively), as well as in patients with intact adrenal function (p<0.05 and a decrease in five/six patients after 6 and 12 months GH, respectively). In conclusion, these results suggest that GH replacement decreases 11betaHSD1 activity, which becomes manifest in patients receiving cortisone acetate substitution therapy. 11betaHSD2 activity is unaltered or may even be increased. It is unlikely that the bioavailability of conventional doses of cortisone acetate is impaired after GH replacement.


Assuntos
Cortisona/análogos & derivados , Cortisona/administração & dosagem , Hormônio do Crescimento Humano/administração & dosagem , Hidrocortisona/urina , Hipopituitarismo/tratamento farmacológico , Hipopituitarismo/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1 , Adulto , Idoso , Cortisona/farmacocinética , Feminino , Humanos , Hidroxiesteroide Desidrogenases/metabolismo , Masculino , Pessoa de Meia-Idade , Água/metabolismo
12.
Int J Pharm ; 217(1-2): 1-11, 2001 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-11292537

RESUMO

The permeability coefficients (log kp) of solutes through stratum corneum have been previously related to the octanol-water partition coefficients (log Poct) and solvatochromic parameters. In this study, permeation coefficient data are related to the theoretical chemistry-derived structural parameters and also molecular connectivity and molecular shape indices. The results show that these parameters are comparable with the solvatochromic parameters in correlation with log kp. Log Poct can be corrected by the theoretical parameters to explain permeation coefficients and the equilibrium distribution of compounds between the stratum corneum and water (log Km). Diffusion estimated from the expression log(D/h)=log kp-log Km, where D is the diffusion coefficient and h is the path length for diffusion was also analyzed successfully by the structural parameters.


Assuntos
Álcoois/química , Modelos Químicos , Relação Quantitativa Estrutura-Atividade , Absorção Cutânea , Esteroides/química , Álcoois/farmacocinética , Cortisona/química , Cortisona/farmacocinética , Epiderme/metabolismo , Etisterona/química , Etisterona/farmacocinética , Ligação de Hidrogênio , Permeabilidade , Progesterona/química , Progesterona/farmacocinética , Absorção Cutânea/fisiologia , Esteroides/farmacocinética
14.
J Exp Zool ; 287(7): 485-92, 2000 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11110162

RESUMO

The entry and metabolism of 3H-cortisol in oocytes were investigated using isolated follicles of the tilapia (Oreochromis mossambicus) in order to examine the mechanisms of incorporation of maternal hormones into oocytes. The composition of 3H-labeled steroids in the oocyte was analyzed by high-performance liquid chromatography. A significant amount of cortisol was converted to cortisone and an unidentified molecule by the follicular layer. The contents of 3H-cortisol and 3H-cortisone in the oocyte reached an equilibrium level within 12 hr, whereas the content of the unidentified metabolite continued to increase for 36 hr. The total content of the incorporated cortisol and its metabolites was proportional to cortisol in the medium over the concentration range of 5 ng/ml to 5 microg/ml. The amounts of cortisone and the unidentified molecule increased proportionally when the concentration of cortisol in the medium was lower than 500 ng/ml, whereas they reached a plateau when the concentration of cortisol exceeded 500 ng/ml. Cortisol entry was reversible, because 90% of cortisol and cortisone in the oocyte was lost within 18 hr when the medium was changed to that without 3H-cortisol. On the other hand, 50% of the unidentified molecule was preserved at the end of the incubation. In conclusion, the entry of cortisol into the oocyte was considered to be nonspecific and due probably to simple diffusion. However, a considerable amount of cortisol (50-70%) was specifically converted to cortisone and another unidentified molecule during passage through the follicular layer.


Assuntos
Cortisona/farmacocinética , Hidrocortisona/farmacocinética , Oócitos/metabolismo , Tilápia , Animais , Transporte Biológico , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Delgada , Difusão , Relação Dose-Resposta a Droga , Feminino , Cinética
15.
J Chromatogr B Biomed Sci Appl ; 738(1): 119-27, 2000 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-10778933

RESUMO

This study describes a capillary GC-MS method for the simultaneous determination of endogenous cortisol and cortisone and their 13C-labelled analogues, [1,2,4,19-13C4]cortisol (cortisol-13C4) and [1,2,4,19-13C4]cortisone (cortisone-13C4), in human plasma. [1,2,4,19-13C4,1,1,19,19,19-2H5]Cortisol (cortisol-13C4,2H5) and [1,2,4,19-13C4,1,1,19,19,19-2H5]cortisone (cortisone-13C4,2H5) were used as analytical internal standards. A double derivatization (bismethylenedioxy-pentafluoropropionate, BMD-PFP) with good GC behavior was employed for the GC-MS analysis of cortisol and cortisone. Quantitation was carried out by selected-ion monitoring of the molecular ions ([M]+*) of the BMD-PFP derivatives of cortisol and cortisone. The sensitivity limit of the present GC-MS-SIM method was found to be 150 pg per injection for cortisol (s/n=5.0) and 50 pg for cortisone (s/n=8.1). The within-day reproducibility in which the amounts of unlabelled and labelled cortisols and cortisones determined were in good agreement with the actual amounts added, the relative errors being less than 3.07%. The inter-assay coefficients of variation (C.V.) were less than 1.80% for unlabelled and labelled cortisols and cortisones.


Assuntos
Cortisona/sangue , Cromatografia Gasosa-Espectrometria de Massas/métodos , Hidrocortisona/sangue , Marcação por Isótopo , Isótopos de Carbono , Cortisona/farmacocinética , Deutério , Humanos , Hidrocortisona/farmacocinética , Técnicas de Diluição do Indicador , Análise de Regressão , Reprodutibilidade dos Testes
16.
J Control Release ; 66(1): 63-71, 2000 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-10708879

RESUMO

The ion pair skin transport of cephalexin was investigated using various counter ions and solvents. The permeability of cephalexin was enhanced by 1-alkylsulfonates (ASs) at pH 3.0 and by tetraalkylammoniums (AAs) at pH 7.0; the enhancing ratio increased with the number of carbon atoms in their alkyl chains. The corresponding effects of these additives were observed on the partitioning of cephalexin. Most of the additives did not affect the skin transport of D-mannitol and cortisone. These results suggest that the enhanced transport of cephalexin results from the ion pair formation with additives. Although ASs increased the partitioning of cephalexin above that of AAs, the transport enhancement effect of ASs was lower than AAs having the same number of carbon atoms in their alkyl chains, indicating higher diffusivity of the ion pairs with AAs in skin. Moreover, the transport enhancement by AAs increased even more when ethanol-buffer solutions were used as solvents. The conductivity measurement of dissolving solutes in donor solvents showed that the further enhancement might be caused by the increasing ion pair formation in solvents with low dielectric constants. To obtain the maximum enhancement of skin transport of zwitterionic drugs via ion pair concept, one should select a counter ion having high lipophilicity and small volume, and a solvent with suitable pH and low dielectric constant.


Assuntos
Cefalexina/farmacocinética , Cefalosporinas/farmacocinética , Absorção Cutânea/fisiologia , Animais , Anti-Inflamatórios/farmacocinética , Transporte Biológico Ativo , Soluções Tampão , Cefalexina/administração & dosagem , Cefalexina/química , Cefalosporinas/administração & dosagem , Cefalosporinas/química , Cortisona/farmacocinética , Difusão , Diuréticos Osmóticos/farmacocinética , Concentração de Íons de Hidrogênio , Masculino , Manitol/farmacocinética , Ratos , Ratos Wistar , Pele/metabolismo , Solubilidade
17.
Aust Vet J ; 77(10): 671-3, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10590797

RESUMO

OBJECTIVE: To evaluate effects of iatrogenic hyperadrenocorticism on plasma cortisol concentrations produced by an infusion of hydrocortisone in dogs. PROCEDURE: Plasma cortisol concentrations were measured regularly during a 6 h infusion of hydrocortisone sodium succinate at two dose rates. The infusions were performed before and after treatment for 30 d with oral cortisone acetate at 10 mg/kg/24 h, divided thrice daily. Adrenal activity during the experimental period was assessed by weekly ACTH stimulation tests. RESULTS: Both infusion rates produced lower plasma cortisol concentrations after treatment for 30 d with cortisone. CONCLUSION: Prior exposure to high concentrations of glucocorticoids may result in accelerated metabolism of glucocorticoids administered subsequently. This may necessitate increased dosages when using glucocorticoids to support inadequate adrenal function.


Assuntos
Hiperfunção Adrenocortical/metabolismo , Anti-Inflamatórios/administração & dosagem , Cortisona/análogos & derivados , Doenças do Cão/metabolismo , Hidrocortisona/administração & dosagem , Hidrocortisona/sangue , Administração Oral , Testes de Função do Córtex Suprarrenal/veterinária , Hiperfunção Adrenocortical/induzido quimicamente , Animais , Anti-Inflamatórios/efeitos adversos , Anti-Inflamatórios/farmacocinética , Cortisona/administração & dosagem , Cortisona/efeitos adversos , Cortisona/farmacocinética , Doenças do Cão/induzido quimicamente , Cães , Feminino , Hidrocortisona/farmacocinética , Infusões Intravenosas/veterinária , Masculino , Fatores de Tempo
18.
Nihon Rinsho ; 52(3): 635-41, 1994 Mar.
Artigo em Japonês | MEDLINE | ID: mdl-8164361

RESUMO

Stable isotopically labeled steroids can, without radiation hazards, be safely used as biological internal standards to perform pharmacokinetic studies of steroids in man. This technique offers an advantage in that an endogenous steroid and its stable isotopically labeled analogue exogenously administered can be differentiated easily by employing mass spectrometry. For example, we can examine the pharmacokinetics of cortisol and investigate the metabolic conversion of cortisol to cortisone in man by administering deuterium-labeled cortisol to human subjects as a tracer. The number and the stability of the label are fundamental requisites in stable isotope methodology. Successful application of methodology with stable isotopes is then always dependent on the availability of compounds that are labeled at predesignated chemically inert positions.


Assuntos
Cortisona/farmacocinética , Deutério , Hidrocortisona/farmacocinética , Marcação por Isótopo/métodos , Prednisolona/farmacocinética , Adolescente , Criança , Ritmo Circadiano , Cromatografia Gasosa-Espectrometria de Massas , Humanos
19.
Res Vet Sci ; 55(3): 379-81, 1993 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8284505

RESUMO

Fasted normal dogs (n = 8) were given fixed doses of cortisone acetate orally as 5 mg and 25 mg tablets; plasma cortisol concentrations were determined, and Cmax, tmax and area under the curve of plasma cortisol concentration plotted against time from zero to 12 hours were compared for the two preparations. In addition, these variables were compared when 25 mg tablets were administered with and without food. No significant difference in cortisol availability was noted for the two preparations and feeding did not apparently affect cortisone absorption. The findings in two hypoadrenocorticoid dogs were similar. Plasma cortisol concentrations in placebo-treated dogs similarly sampled showed minor fluctuations and were generally within accepted reference limits for normal dogs.


Assuntos
Cortisona/farmacocinética , Cães/sangue , Hidrocortisona/sangue , Absorção , Administração Oral , Animais , Disponibilidade Biológica , Cortisona/administração & dosagem , Ingestão de Alimentos , Feminino , Masculino , Radioimunoensaio/veterinária
20.
Chem Pharm Bull (Tokyo) ; 40(11): 3097-9, 1992 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1477927

RESUMO

The effect of l-menthol on the skin permeability of mannitol, cortisone or indomethacin was examined by an in vitro penetration technique with hairless mouse skin. The donor solution was prepared with phosphate buffered saline, ethanol:buffered saline (20:80, v/v) or ethanol:buffered saline (20:80, v/v) containing 1% (w/v) l-menthol. Although ethanol showed little enhancing effect, l-menthol in an aqueous ethanol vehicle at pH 7.4 increased the permeability coefficients of mannitol and indomethacin by about 100 times that of the control (an aqueous vehicle) and increased that of cortisone by about 10 times. l-Menthol, however, scarcely enhanced the penetration of indomethacin at pH 3.0, the majority of the species being in unionized form. These results suggested that the menthol-ethanol-aqueous system enhanced skin permeability through a direct effect on the polar and/or lipid pathways, while the thermodynamic activity of the penetrant molecule in the delivery vehicle might also influence the effectiveness of the penetration enhancer.


Assuntos
Cortisona/farmacocinética , Indometacina/farmacocinética , Manitol/farmacocinética , Mentol/farmacologia , Pele/metabolismo , Administração Cutânea , Animais , Cromatografia Líquida de Alta Pressão , Cortisona/administração & dosagem , Técnicas In Vitro , Indometacina/administração & dosagem , Camundongos , Permeabilidade/efeitos dos fármacos , Pele/efeitos dos fármacos
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