RESUMO
PURPOSE: The diminished function of 11ß-hydroxysteroid dehydrogenase 2 (11ß-HSD2) was found in placentae from preeclamptic pregnancies. Here, we examine the overall maternal glucocorticoid balance in pregnancy-related hypertension. We aim to answer the question if the functions of primary enzymes involved in cortisol metabolism: 11ß-HSD1 and 11ß-HSD2 and 5-reductases (both 5α- and 5ß) are altered in the course of hypertensive pregnancy. METHODS: We determined plasma and urinary cortisol and cortisone as well as their urinary tetrahydro- and allo-tetrahydrometabolites, both in free and conjugated forms in samples obtained from 181 Polish women in the third trimester of pregnancy. We compared steroid profiles in women with preeclampsia (PE), gestational hypertension (GH), chronic hypertension (CH) and in normotensives (controls). RESULTS: We found significant differences in glucocorticoid balance in pregnancy-related hypertension. Plasma cortisol to cortisone was significantly lower in PE than in controls (3.00 vs. 4.79; p < 0.001). Increased function of renal 11ß-HSD2 in PE and GH was manifested by significantly lower urinary free cortisol to cortisone ratio (0.169 and 0.206 vs. 0.277 in controls; p < 0.005). Markedly enhanced metabolism of cortisol was observed in pregnancy-related hypertension, with no significant alterations in CH, and the changes were more clearly expressed in PE than in GH. CONCLUSIONS: The glucocorticoid balance in PE and GH is shifted towards decreasing cortisol concentration either due to intensified conversion to cortisone or enhanced production of tetrahydro and allo-tetrahydrometabolites.
Assuntos
Hidrocortisona/metabolismo , Hipertensão Induzida pela Gravidez/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/sangue , Adulto , Cortisona/metabolismo , Feminino , Humanos , Hipertensão/sangue , Rim/enzimologia , Limite de Detecção , Pré-Eclâmpsia/sangue , Gravidez , Adulto JovemRESUMO
Glucocorticoid-induced osteoporosis is one of the common causes of secondary osteoporosis. Piper sarmentosum (Ps) extract possesses antioxidant and anti-inflammatory activities. In this study, we determined the correlation between the effects of Ps leaf water extract with the regulation of 11ß-hydroxysteroid dehydrogenase (HSD) type 1 enzyme activity in serum and bone of glucocorticoid-induced osteoporotic rats. Twenty-four Sprague-Dawley rats were grouped into following: G1: sham-operated group administered with intramuscular vehicle olive oil and vehicle normal saline orally; G2: adrenalectomized (adrx) control group given intramuscular dexamethasone (120 µg/kg/day) and vehicle normal saline orally; G3: adrx group given intramuscular dexamethasone (120 µg/kg/day) and water extract of Piper sarmentosum (125 mg/kg/day) orally. After two months, the femur and serum were taken for ELISA analysis. Results showed that Ps leaf water extract significantly reduced the femur corticosterone concentration (p < 0.05). This suggests that Ps leaf water extract was able to prevent bone loss due to long-term glucocorticoid therapy by acting locally on the bone cells by increasing the dehydrogenase action of 11ß-HSD type 1. Thus, Ps may have the potential to be used as an alternative medicine against osteoporosis and osteoporotic fracture in patients on long-term glucocorticoid treatment.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Glucocorticoides/efeitos adversos , Osteoporose/etiologia , Osteoporose/metabolismo , Piper/química , Extratos Vegetais/farmacologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Biomarcadores , Peso Corporal/efeitos dos fármacos , Corticosterona/sangue , Corticosterona/metabolismo , Modelos Animais de Doenças , Osteoporose/sangue , Osteoporose/tratamento farmacológico , Extratos Vegetais/química , RatosRESUMO
Childhood nephrotic syndrome, in which steroid-dependence occurs concurrently with steroid-resistance, requires aggressive therapy to prevent relapse. Predictive biomarkers that can be used to stratify treatment are urgently needed. Here we report that reciprocal regulation of the glucocorticoid metabolizing enzymes, 11ß-hydroxysteroid dehydrogenase types 1 and 2, is associated with steroid-responsiveness and disease remission in childhood nephrotic syndrome, potentially providing a marker to identify patients in which aggressive therapy is required.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/sangue , Anti-Inflamatórios/uso terapêutico , Resistência a Medicamentos , Tolerância a Medicamentos , Síndrome Nefrótica/tratamento farmacológico , Prednisolona/uso terapêutico , Adolescente , Biomarcadores/sangue , Criança , Pré-Escolar , Dexametasona/uso terapêutico , Esquema de Medicação , Feminino , Humanos , Quimioterapia de Indução , Quimioterapia de Manutenção , Masculino , Síndrome Nefrótica/sangue , Síndrome Nefrótica/diagnóstico , Síndrome Nefrótica/enzimologia , Receptores de Glucocorticoides/sangue , Recidiva , Resultado do TratamentoRESUMO
The local concentration of glucocorticoids is intensively regulated by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD 1). Human 11beta-HSD 1 also reversibly catalyzes the inter-conversion of 7alpha-hydroxy- and 7beta-hydroxy-dehydroepiandrosterone (DHEA) into 7-oxo-DHEA. The cohort of 282 obese adolescents, 154 girls (median age 15.31 years, range 14.17-16.68 years) and 128 boys (median age 14.95 years, range 13.87-16.16 years), BMI (Body Mass Index) >90th percentile was examined. In samples collected before and after one month of reductive diet therapy, circulating levels of steroids were analyzed by liquid chromatography-tandem mass spectrometry and radioimmunoassay methods. The model of the treatment efficacy prediction was calculated. A significant reduction in circulating levels of cortisone, E2 and increased levels of 7beta-hydroxy-DHEA after the reductive treatment was observed. Levels of cortisol, DHEA, DHT sustained without any significant change. The predictive Orthogonal Projections to Latent Structures (OPLS) model explained 20.1 % of variability of BMI, z-score change by the basal levels of 7alpha-hydroxy-DHEA, DHEA, cortisol and E2 as the strongest predictors. Reduced levels of circulating cortisone and reduced ratios of oxygenated/reduced metabolites reflect increased reductase activity of 11beta-HSD 1 with reduced BMI, z-score. We hypothesize whether these changes can be attributed to the altered activity of 11beta-HSD 1 in the liver.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Desidroepiandrosterona/sangue , Dieta Redutora/tendências , Obesidade/sangue , Obesidade/terapia , Adolescente , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Fígado/metabolismo , Masculino , Resultado do TratamentoRESUMO
Flaxseed (Linum usitatissimum L.) has been a focus of interest in the field of functional foods because of its potential health benefits. However, we hypothesised that maternal flaxseed intake during lactation could induce several metabolic dysfunctions in adult offspring. In the present study, we aimed to characterise the adrenal function of adult offspring whose dams were supplemented with whole flaxseed during lactation. At birth, lactating Wistar rats were divided into two groups: rats from dams fed the flaxseed diet (FLAX) with 25% of flaxseed and controls dams. Pups received standard diet after weaning and male offspring were killed at age 180 days old to collect blood and tissues. We evaluated body weight and food intake during development, corticosteronaemia, adrenal catecholamine content, hepatic cholesterol, TAG and glycogen contents, and the protein expression of corticotropin-releasing hormone (CRH), adrenocorticotropic hormone (ACTH), 11-ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) and adrenaline ß2 receptor at postnatal day 180 (PN180). After weaning, pups from the FLAX group had a higher body weight (+10 %) and food intake (+10%). At PN180, the FLAX offspring exhibited higher serum corticosterone (+48%) and lower adrenal catecholamine ( - 23%) contents, lower glycogen ( - 30%), higher cholesterol (4-fold increase) and TAG (3-fold-increase) contents in the liver, and higher 11ß-HSD1 (+62%) protein expression. Although the protein expression of hypothalamic CRH was unaffected, the FLAX offspring had lower protein expression of pituitary ACTH ( - 34%). Therefore, induction of hypercorticosteronaemia by dietary flaxseed during lactation may be due to an increased hepatic activation of 11ß-HSD1 and suppression of ACTH. The changes in the liver fat content of the FLAX group are suggestive of steatosis, in which hypercorticosteronaemia may play an important role. Thus, it is recommended that lactating women restrict the intake of flaxseed during lactation.
Assuntos
Glândulas Suprarrenais/fisiopatologia , Linho/efeitos adversos , Lactação , Fenômenos Fisiológicos da Nutrição Materna , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Hormônio Adrenocorticotrópico/sangue , Animais , Peso Corporal , Catecolaminas/metabolismo , Colesterol/sangue , Corticosterona/sangue , Dieta/veterinária , Feminino , Glicogênio/sangue , Fígado/metabolismo , Masculino , Modelos Animais , Estado Nutricional , Ratos , Ratos Wistar , Triglicerídeos/sangue , DesmameRESUMO
OBJECTIVE: Dysregulation of enzymes that control local tissue steroid metabolism has been implicated in the pathogenesis of obesity and insulin resistance; however, longitudinal changes in glucocorticoid metabolism have not been investigated. This study was performed to evaluate the role of glucocorticoid metabolism in the development of insulin resistance and obesity and to identify biomarkers for future development of metabolic disease. DESIGN: This was a prospective longitudinal observation study conducted over 5 years. METHODS: A 24-h collection was used to serially analyze urinary glucocorticoid and mineralocorticoid metabolites in 57 obese and overweight patients with no prior diagnosis of diabetes mellitus, recruited from the community. RESULTS: Baseline higher 5α-reductase (5αR) activity, but not 11ß-hydroxysteroid dehydrogenase type 1 activity, was predictive of increased fasting insulin at final visit (11.4 compared with 7.4âmU/l in subjects with lower 5αR activity, P<0.05), area under the curve insulin response to oral glucose tolerance test (176.7 compared with 89.1âmU/l.h, P<0.01), and homeostasis model assessment (HOMA2-IR; 1.3 compared with 0.8, P<0.01). Higher total glucocorticoid production was associated with abnormal glucose tolerance and increased BMI. During this study, systolic blood pressure increased (equivalent to â¼1âmmHg/year), as did plasma sodium levels; this evidence of increased mineralocorticoid activity was associated with increased aldosterone metabolites and decreased 11ß-hydroxysteroid dehydrogenase type 2 activity. CONCLUSIONS: Increased 5αR activity and glucocorticoid secretion rate over time are linked with the development of metabolic disease, and may represent targets for therapeutic intervention, which merits further study.
Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/metabolismo , Glucocorticoides/metabolismo , Insulina/sangue , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/urina , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/urina , Adulto , Idoso , Pressão Sanguínea , Feminino , Glucocorticoides/sangue , Glucocorticoides/urina , Humanos , Insulina/metabolismo , Resistência à Insulina , Modelos Lineares , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Mineralocorticoides/metabolismo , Fenótipo , Valor Preditivo dos Testes , Estudos ProspectivosRESUMO
ABT-384 is a potent and selective inhibitor of 11ß-hydroxysteroid dehydrogenase type 1 (HSD-1). The pharmacokinetics of ABT-384 was evaluated in healthy volunteers in single-dose (1, 8, 20, 50, 120 and 240 mg) and multiple-dose studies (1, 2, 4, 8, 20, 30 and 100 mg once daily). Less than dose-proportional pharmacokinetics of ABT-384 was observed when ABT-384 was administered at single doses lower than 8 mg. This nonlinear phenomenon disappeared after repeated doses. The dose-normalized plasma concentration-time curves superposed across all dose groups on day 7, but not on day 1. This phenomenon cannot be explained by the half-life of ABT-384. Based on available data, the nonlinearity is likely due to binding of ABT-384 to a high-affinity-low-capacity site, such that this interaction was reflected in ABT-384 pharmacokinetics. To characterize the pharmacokinetics of ABT-384, a population pharmacokinetic model for ABT-384 was constructed. The model provided reasonable fitting for both single- and multiple-dose data. Further investigation is warranted to evaluate the disposition of ABT-384 at low doses using a larger number of subjects. The constructed model would be useful in predicting ABT-384 concentrations at different doses and guiding the selection of dosing regimens in further clinical trials.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Adamantano/análogos & derivados , Piperazinas/administração & dosagem , Piperazinas/sangue , Adamantano/administração & dosagem , Adamantano/sangue , Adamantano/farmacocinética , Adulto , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Piperazinas/farmacocinética , Adulto JovemRESUMO
AIM: Physical exercise reduces obesity, insulin resistance and dyslipidemia. We previously found that maternal obesity alters central appetite circuits and contributes to increased adiposity, glucose intolerance and metabolic disease in offspring. Here we hypothesized that voluntary exercise would ameliorate the adverse metabolic effects of maternal obesity on offspring. METHODS AND RESULTS: Sprague-Dawley females fed chow (C) or high-fat diet HFD (H) were mated. Female offspring from C dams were weaned onto chow (CC); those from H dams recieved chow (HC) or HFD (HH). Half of each group was provided with running wheels (CC(EX), HC(EX), HH(EX); n=10-12). Maternal obesity increased body weight (12%), adiposity, plasma lipids and induced glucose intolerance (HC vs CC; P<0.05). These were exaggerated by postweaning HFD (HH vs HC; P<0.01), showed doubled energy intake, a 37% increase in body weight, insulin resistance and glucose intolerance (HH vs HC; P<0.01). Exercise reduced fat mass, plasma lipids, HOMA and fasting glucose in HC(EX) (vs HC; P<0.05) and HH(EX) (vs HH; P<0.01). Values in HC(EX) were indistinguishable from CC, however in HH(EX) these metabolic parameters remained higher than the sedentary HC and CC rats (P<0.01). mRNA expression of hypothalamic pro-opiomelanocortin, and adipose tumour necrosis factor α and 11ß-hydroxysteroid dehydrogenase type 1 were reduced by exercise in HH(EX) (vs HH; P<0.05). CONCLUSION: While voluntary exercise almost completely reversed the metabolic effects of maternal obesity in chow fed offspring, it did not fully attenuate the increased adiposity, glucose intolerance and insulin resistance in offspring weaned onto HFD.
Assuntos
Homeostase/fisiologia , Fenômenos Fisiológicos da Nutrição Materna , Obesidade/metabolismo , Condicionamento Físico Animal/fisiologia , Desmame , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Adiposidade , Fenômenos Fisiológicos da Nutrição Animal , Animais , Apetite/fisiologia , Glicemia/análise , Pressão Sanguínea , Peso Corporal , Dieta Hiperlipídica , Dislipidemias/metabolismo , Ingestão de Energia , Ácidos Graxos não Esterificados/sangue , Feminino , Hipotálamo/metabolismo , Insulina/sangue , Resistência à Insulina , Leptina/sangue , Pró-Opiomelanocortina/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Triglicerídeos/sangue , Fator de Necrose Tumoral alfa/sangueRESUMO
AIM: The objective of this study was to investigate low-grade inflammation in children with type 1 diabetes (T1D) and its association with cortisol levels as well as its bioavailability through 11ß-hydroxy steroid dehydrogenase type 1 (11ß-HSD1) activity. METHODS: Children with T1D (n=45) and their non-diabetic siblings (n=28) participated in the study. Interleukin-6 (IL-6) and high-sensitivity C-reactive protein (CRPhs) were measured between 1400 and 1800h. Glucocorticoid metabolites were measured in the first morning urine on clinic day and 11ß-HSD1 activity was estimated by tetrahydrocortisol/tetrahydrocortisone (THF/THE) ratio. RESULTS: Diabetic patients presented with an increased THF/THE ratio compared with controls (median: 0.68 [range: 0.45-1.18] vs 0.45 [0.27-0.98], respectively; P<10(-3)). There was no difference between diabetic patients and controls for IL-6 (0.6ng/mL [0.6-6.8] vs 0.6 [0.6-2.2], respectively; P=0.43) and CRPhs (0.4mg/L [0-7.4] vs 0.3 [0-8.2]; P=0.26, respectively). When adjusted for age, gender and BMI, the THF/THE ratio was significantly associated with CRPhs (ß=0.32, P=0.02) in diabetic patients, but not in controls. CONCLUSION: Low-grade inflammation assessed by plasma CRPhs and IL-6 concentrations was not detectable in our cohort of T1D children. Nocturnal 11ß-HSD1 activity was increased and associated with plasma CRPhs concentration in diabetic patients. These results may be explained by either a direct or inflammation-mediated effect of the relative hepatic lack of insulin due to subcutaneous insulin therapy.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Proteína C-Reativa/metabolismo , Diabetes Mellitus Tipo 1/sangue , Hidrocortisona/sangue , Insulina/sangue , Interleucina-6/sangue , Adolescente , Biomarcadores/sangue , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Feminino , França/epidemiologia , Glucocorticoides , Humanos , Hipoglicemiantes/administração & dosagem , Inflamação/sangue , Injeções Subcutâneas , Insulina/administração & dosagem , Masculino , Irmãos , Fatores de TempoRESUMO
INTRODUCTION: Cortisol levels in patients with rheumatoid arthritis (RA) are considered inadequate to ongoing inflammation. One possible mechanism ofthe relative cortisol deficit can be decreased 11beta-hydroxysteroid dehydrogenase type 1 (11BHSD1) activity, an enzyme that converts inactive cortisone to active cortisol. The aim of the study was to determine systemic and local activity of 11 BHSD1 in female patients with RA. METHODS: Six female RA patients without glucocorticoid therapy (age 29 +/- 2 years, BMI 21 +/- 1 kg/m2) and six healthy women (age 30 +/- 2 years, BMI 21 +/- 1 kg/m2) were studied. Endogenous cortisol production was suppressed by dexamethasone. 11BHSD1 activity was evaluated by changes in concentrations of total plasma, free plasma, salivary and cortisol in subcutaneous adipose tissue after cortisone acetate administration (25 mg per os). RESULTS: Concentrations of total plasma, free plasma, salivary, and tissue cortisol increased significantly, however there was no significant difference between RA patients and controls. CONCLUSION: The result suggests comparable systemic and adipose tissue conversion of cortisone to cortisol. Despite chronic inflammation, systemic activity of 11BHSD1 is not responsible for relative adrenal deficiency in RA. Changes in local activity of the enzyme in tissues affected by inflammatory process cannot be excluded.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Artrite Reumatoide/enzimologia , Adulto , Artrite Reumatoide/sangue , Feminino , Humanos , Hidrocortisona/sangueRESUMO
OBJECTIVE: Our objective was to demonstrate that the smaller oxoreductase activity of 11beta-HSD1 in women would shift the interconversion of cortisol and cortisone toward cortisone, resulting in a larger amount of generated labeled cortisone in healthy women than in healthy men. RESEARCH METHODS AND PROCEDURES: Using mass spectrometry, the amount of cortisone generated from a continuous infusion (8 am to 6 pm) of stable-labeled cortisol (1alpha,2alpha-d-cortisol) was determined in non-obese and in obese (BMI>35 kg/m2) men and women during steady-state conditions (from 2 pm to 6 pm). In this setting, the amount of generated labeled cortisone (expressed as % of the achieved steady-state concentrations of labeled cortisol) reflects the sum of the bi-directional conversion of cortisol into cortisone (and vice versa) by 11beta-hydroxysteroid dehydrogenase. RESULTS: The amount of generated labeled cortisone was higher in men than in women (p<0.0001). This sex difference was higher in obese than in non-obese patients (p=0.0062). CONCLUSIONS: The interconversion of cortisol and cortisone during steady-state conditions is shifted toward cortisol in men as compared with women. This suggests a higher overall oxoreductase activity of 11beta-hydroxysteroid dehydrogenase type 1 in men than in women. This sex-specific difference is maintained in obesity.
Assuntos
Cortisona/sangue , Cortisona/urina , Hidrocortisona/sangue , Hidrocortisona/urina , Obesidade/sangue , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Adulto , Índice de Massa Corporal , Cromatografia Líquida , Feminino , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Íons , Masculino , Fatores Sexuais , Tetra-Hidrocortisol/urina , Tetra-Hidrocortisona/urinaRESUMO
OBJECTIVE: In the past years the interaction of GH and 11beta hydroxysteroid dehydrogenase (11betaHSD) in the pathogenesis of central obesity has been suggested. DESIGN: We studied the effects of 9 months of GH treatment on 11betaHSD activity and its relationship with body composition and insulin sensitivity in 30 men with abdominal obesity, aged 48-66 years, in a randomised, double-blind, placebo-controlled trial. METHODS: Urinary steroid profile was used to estimate 11betaHSD type 1 and 2 (11betaHSD1 and 11betaHSD2) activities. Abdominal s.c. and visceral adipose tissues were measured using computed tomography. Glucose disposal rate (GDR) obtained during a euglycaemic-hyperinsulinaemic glucose clamp was used to assess insulin sensitivity. RESULTS: In the GH-treated group the 11betaHSD1 activity decreased transiently after 6 weeks (P < 0.01) whereas 11betaHSD2 increased after 9 months of treatment (P < 0.05). Between 6 weeks and 9 months, GDR increased and visceral fat mass decreased. Changes in 11betaHSD1 correlated with changes in visceral fat mass between baseline and 6 weeks. There were no significant correlations between 11betaHSD1 and 11betaHSD 2 and changes in GDR. DISCUSSION: The study demonstrates that short- and long-term GH treatment has different effects on 11betaHSD1 and 11betaHSD2 activity. Moreover, the data do not support that long-term metabolic effects of GH are mediated through its action on 11betaHSD.
Assuntos
11-beta-Hidroxiesteroide Desidrogenases/sangue , Hormônio do Crescimento Humano/uso terapêutico , Obesidade/tratamento farmacológico , Obesidade/enzimologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , 11-beta-Hidroxiesteroide Desidrogenase Tipo 2/sangue , 11-beta-Hidroxiesteroide Desidrogenases/efeitos dos fármacos , Gordura Abdominal/efeitos dos fármacos , Hormônio do Crescimento Humano/administração & dosagem , Humanos , Hidrocortisona/sangue , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
INTRODUCTION: Free fatty acids (FFAs) induce hepatic insulin resistance and enhance hepatic gluconeogenesis. Glucocorticoids (GCs) also stimulate hepatic gluconeogenesis. The aim of this study was to investigate whether the FFA-induced hepatic insulin resistance is mediated by increased activity of hepatic 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), accompanied by elevated hepatic cortisol levels. METHODS: Following a 10-h overnight fast, six healthy male volunteers were investigated. A euglycaemic hyperinsulinaemic clamp was performed during lipid or saline infusion. To assess hepatic 11beta-HSD1 activity, plasma cortisol levels were measured after oral administration of cortisone acetate during lipid or saline infusion. In addition, 11beta-HSD activities were determined in vivo by calculating the urinary ratios of GC metabolites. RESULTS: Lipid infusion increased FFAs (5.41 +/- 1.00 vs. 0.48 +/- 0.20 mmol/l; P < 0.005) and significantly increased insulin resistance [glucose infusion rate (GIR) 6.02 +/- 2.60 vs. 4.08 +/- 2.15 mg/kg/min; P < 0.005]. After lipid and saline infusions no changes in 11beta-HSD1 activity were found, neither by changes in cortisone acetate to cortisol conversion nor by differences in urinary free cortisol (UFF) or cortisone (UFE), 5beta-tetrahydrocortisol (THF), 5alpha-THF, cortisone (THE), UFF/UFE and (5alpha-THF + THF)/THE ratios. CONCLUSIONS: We found no change in hepatic and whole-body 11beta-HSD1 activity during acute FFA-induced insulin resistance. Further studies are necessary to clarify whether 11beta-HSD1 in muscle and adipose tissue is influenced by FFAs and whether 11beta-HSD1 is involved in other conditions of insulin resistance.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Ácidos Graxos não Esterificados/metabolismo , Resistência à Insulina , Fígado/enzimologia , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/sangue , Hormônio Adrenocorticotrópico/urina , Adulto , Cortisona/análogos & derivados , Cortisona/urina , Ativação Enzimática , Glucose/administração & dosagem , Humanos , Hidrocortisona/sangue , Hidrocortisona/urina , Insulina/administração & dosagem , Lipídeos/administração & dosagem , Masculino , Estudos Prospectivos , Tetra-Hidrocortisol/urinaRESUMO
Glucocorticoids are potent regulators of protein, fat, and carbohydrate metabolism. To determine if cortisol production occurs within the splanchnic bed in humans, 11 nondiabetic subjects were studied using the hepatic/leg catheterization method along with an infusion of [9,11,12,12-2H4] cortisol (D4-cortisol) as proposed by Andrews et al. In the fasting state, there was net release (P < 0.05) of cortisol from the splanchnic bed (6.1 +/- 2.6 microg/min) and net uptake (P < 0.05) by the leg (1.7 +/- 0.7 microg/min). This, along with cortisol production by other tissues (e.g., the adrenals), resulted in a total-body cortisol appearance rate of 18.1 +/- 1.9 microg/min. Fractional splanchnic D4-cortisol extraction averaged 12.9 +/- 1.3% (P < 0.001), splanchnic cortisol uptake 14.8 +/- 2.0 microg/min (P < 0.001), and splanchnic cortisol production 22.2 +/- 3.3 microg/min (P < 0.001). On the other hand, fractional leg D4-cortisol extraction averaged 5.6 +/- 1.8% (P < 0.02), leg cortisol uptake 2.3 +/- 0.7 microg/min (P < 0.01), and leg cortisol production 0.4 +/- 0.4 microg/min, which did not differ from zero. Because D4-cortisol loses a deuterium during conversion to [9,12,12-2H3] cortisone (D3-cortisone), which in turn generates [9,12,12(2)H3] cortisol (D3-cortisol) via 11-beta hydroxysteroid dehydrogenase (11beta-HSD) type 1, D3-cortisol production can be used as an index of 11beta-HSD type 1 activity. Net splanchnic D3-cortisol release (3.9 +/- 0.4 microg/min) and splanchnic D3-cortisol production (7.1 +/- 0.7 microg/min) occurred (P < 0.01) in all subjects. In contrast, there was minimal leg D3-cortisol production (0.04 +/- 0.01 microg/min), resulting in a strong correlation between splanchnic D3-cortisol production and total-body 3D-cortisol production in both the fasting state (r = 0.84; P < 0.02) and during an infusion of insulin (r = 0.97; P < 0.01). Thus, splanchnic production of cortisol occurs in nondiabetic humans at rates approximating that which occurs in the remainder of the body. These data support the possibility that alterations in splanchnic cortisol production contribute to visceral fat accumulation and the hepatic insulin resistance of obesity or type 2 diabetes.