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1.
Diabetologia ; 55(10): 2779-2788, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22790061

RESUMO

AIMS/HYPOTHESIS: The cAMP-degrading phosphodiesterase 4 (PDE4) enzyme has recently been implicated in the regulation of glucagon-like peptide-1 (GLP-1), an incretin hormone with glucose-lowering properties. We investigated whether the PDE4 inhibitor roflumilast elevates GLP-1 levels in diabetic db/db mice and whether this elevation is accompanied by glucose-lowering effects. METHODS: Plasma GLP-1 was determined in db/db mice after single oral administration of roflumilast or its active metabolite roflumilast-N-oxide. Diabetes-relevant variables including HbA(1c), blood glucose, serum insulin, body weight, food and water intake, and pancreas morphology were determined in db/db mice treated daily for 28 days with roflumilast or roflumilast-N-oxide. Pharmacokinetic/pharmacodynamic analysis clarified the contribution of roflumilast vs its metabolite. In addition, the effect of roflumilast-N-oxide on insulin release was investigated in primary mouse islets. RESULTS: Single treatment of db/db mice with 10 mg/kg roflumilast or roflumilast-N-oxide enhanced plasma GLP-1 2.5- and fourfold, respectively. Chronic treatment of db/db mice with roflumilast or roflumilast-N-oxide at 3 mg/kg showed prevention of disease progression. Roflumilast-N-oxide abolished the increase in blood glucose, reduced the increment in HbA(1c) by 50% and doubled fasted serum insulin compared with vehicle, concomitant with preservation of pancreatic islet morphology. Furthermore, roflumilast-N-oxide amplified forskolin-induced insulin release in primary islets. Roflumilast-N-oxide showed stronger glucose-lowering effects than its parent compound, consistent with its greater effect on GLP-1 secretion and explainable by pharmacokinetic/pharmacodynamic modelling. CONCLUSIONS/INTERPRETATION: Our results suggest that roflumilast and roflumilast-N-oxide delay the progression of diabetes in db/db mice through protection of pancreatic islet physiology potentially involving GLP-1 and insulin activities.


Assuntos
Aminopiridinas/farmacologia , Benzamidas/farmacologia , Diabetes Mellitus Tipo 2/metabolismo , Hipoglicemiantes/farmacologia , Inibidores da Fosfodiesterase 4/farmacologia , Administração Oral , Aminopiridinas/administração & dosagem , Aminopiridinas/uso terapêutico , Animais , Benzamidas/administração & dosagem , Benzamidas/uso terapêutico , Glicemia/metabolismo , Ciclopropanos/administração & dosagem , Ciclopropanos/farmacologia , Ciclopropanos/uso terapêutico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/prevenção & controle , Modelos Animais de Doenças , Progressão da Doença , Feminino , Peptídeo 1 Semelhante ao Glucagon/metabolismo , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/uso terapêutico , Insulina/sangue , Camundongos , Camundongos Mutantes , Inibidores da Fosfodiesterase 4/administração & dosagem , Inibidores da Fosfodiesterase 4/uso terapêutico
2.
Nuklearmedizin ; 50(3): 101-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21165538

RESUMO

UNLABELLED: FDG-PET/CT is increasingly used in staging of lung cancer as single "one stop shop" method. AIM, PATIENTS, METHODS: We prospectively included 104 neurological asymptomatic patients (65 years, 26% women) with primary diagnosis of lung cancer. In all patients PET/CT including cerebral imaging and cerebral MRI were performed. RESULTS: Diagnosis of brain metastases (BM) was made by PET/CT in 8 patients only (7.7%), by MRI in 22 (21.2%). In 80 patients both PET/CT and MRI showed no BM. In 6 patients (5.8%) BM were detectable on PET/CT as well as on MRI. Exclusive diagnosis of BM by MRI with negative finding on PET/CT was present in 16 patients (15.4%). 2 patients (1.9%) had findings typical for BM on PET/CT but were negative on MRI. With MRI overall 100 BM were detected, with PET/CT only 17 BM (p < 0.01). For the diagnosis of BM PET/CT showed a sensitivity of 27.3%, specificity of 97.6%, positive predictive value of 75% and negative predictive value of 83.3%. BM diameter on PET/CT and MRI were consistent in 43%, in 57% BM were measured larger on MRI. DISCUSSION: Compared to the gold standard of MRI for cerebral staging a considerable number of patients are falsely diagnosed as free from BM by PET/CT. MRI is more accurate than PET/CT for detecting multiple and smaller BM. CONCLUSION: In patients with a curative option MRI should be performed additionally to PET/CT for definitive exclusion of brain metastases.


Assuntos
Neoplasias Encefálicas/epidemiologia , Neoplasias Encefálicas/secundário , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/epidemiologia , Imageamento por Ressonância Magnética/estatística & dados numéricos , Tomografia por Emissão de Pósitrons/estatística & dados numéricos , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/diagnóstico , Carcinoma/diagnóstico , Carcinoma/epidemiologia , Carcinoma/secundário , Feminino , Fluordesoxiglucose F18 , Alemanha/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prevalência , Compostos Radiofarmacêuticos , Reprodutibilidade dos Testes , Medição de Risco , Fatores de Risco , Sensibilidade e Especificidade
3.
Clin Investig ; 70(7): 566-72, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1392425

RESUMO

Patients with chronic liver disease usually exhibit low plasma levels of testosterone with loss of libido and potency; this is also valid in male patients suffering from idiopathic hemochromatosis (IHC), in whom nowadays the diagnosis is made at an earlier age. Therefore, the effect of testosterone treatment was studied in 10 patients with IHC. After the application of 250 mg testosterone enanthate i.m., the plasma testosterone (from 2.4 +/- 1.9 to 20.1 +/- 7.4 ng/ml) and estradiol (from 17.4 +/- 6.3 to 38.5 +/- 14.2 pg/ml) levels increased significantly. The rise of estradiol was in the range of controls and smaller than reported in other chronic liver diseases. In a long-term study, 250 mg testosterone enanthate was given 4-weekly for 33-96 months to 5 patients with IHC. General well-being, libido, and potency recovered almost immediately. Over a treatment period of 27.3 patient years, symptoms of hyperestrogenism (gynecomastia) or (portal vein) thrombosis were not seen, both of which had been described in patients with alcoholic liver cirrhosis. There was no deterioration of liver function. The effect of testosterone treatment on the patients' well-being and plasma hormone concentrations remained unchanged over the whole period of testosterone treatment. Thus, in male patients with IHC and lowered plasma testosterone, treatment with testosterone enanthate may be instituted. Because of the positive effects on general well-being, liver regeneration capacity, and potency, testosterone should especially be administered to younger subjects suffering from IHC.


Assuntos
Hemocromatose/tratamento farmacológico , Testosterona/análogos & derivados , Adulto , Disfunção Erétil/tratamento farmacológico , Disfunção Erétil/etiologia , Hormônios Esteroides Gonadais/sangue , Hemocromatose/sangue , Hemocromatose/complicações , Humanos , Libido/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Globulina de Ligação a Hormônio Sexual/análise , Testosterona/farmacologia , Testosterona/uso terapêutico
4.
J Clin Endocrinol Metab ; 74(3): 685-9, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1311000

RESUMO

Adrenal tumors are being detected more frequently in consequence of the wider application of increasingly sensitive radiological investigation techniques. According to the working hypothesis that more silent adenomas could develop from hyperplastic tissue areas under increased stimulation of the adrenal cortex, heterozygous and homozygous patients with congenital adrenal hyperplasia (CAH) were studied. A high incidence of adrenal masses, nearly 82% in homozygous and 45% in heterozygous patients, was found. There was no correlation between tumor size and serum 17-hydroxyprogesterone concentrations. These tumors are, therefore, probably silent adenomas. On the basis of these results, CAH should always be ruled out in the case of incidentally detected adrenal masses. Since CAH is a relatively frequent disease, and the adrenal carcinoma belongs to the rarest malignant tumors, a malignant transformation of these tumors seems to be unlikely.


Assuntos
Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Hiperplasia Suprarrenal Congênita/complicações , 17-alfa-Hidroxiprogesterona , Neoplasias das Glândulas Suprarrenais/complicações , Hiperplasia Suprarrenal Congênita/diagnóstico por imagem , Hiperplasia Suprarrenal Congênita/genética , Hormônio Adrenocorticotrópico , Adulto , Cortodoxona/sangue , Desidroepiandrosterona/sangue , Feminino , Heterozigoto , Homozigoto , Humanos , Hidroxiprogesteronas/sangue , Masculino , Tomografia Computadorizada por Raios X
5.
J Steroid Biochem Mol Biol ; 40(4-6): 731-3, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1958571

RESUMO

The secretion of dehydroepiandrosterone (DHEA) and its sulfate is known to decline gradually with advancing age. Furthermore DHEA is known to be significantly lower in osteoporotic subjects than in normals. Recently 11 beta-hydroxyandrostenedione (11-OHA) has been proposed as an important indicator of the adrenal source of hormone excess in different hyperandrogenic states. In the present study we measured 11-OHA in 224 normal women aged 20-79 yr and 130 osteoporotic women aged 40-79 yr. RIA of 11-OHA was performed with highly specific antiserum raised in rabbits. The mean 11-OHA serum concentration was 2.20 +/- 0.90 ng/ml in normal women and 1.75 +/- 0.58 ng/ml in osteoporotic women. In contrast to DHEA there was no age-related decrease in 11-OHA serum concentrations in normal and osteoporotic women. Osteoporotic subjects showed statistically significantly lower 11-OHA serum concentrations than normal women. Therefore low serum 11-OHA might represent a further risk factor for osteoporosis.


Assuntos
Envelhecimento , Androstenodiona/análogos & derivados , Osteoporose/sangue , Córtex Suprarrenal/metabolismo , Adulto , Idoso , Androstenodiona/sangue , Feminino , Humanos , Pessoa de Meia-Idade
8.
Klin Wochenschr ; 68(6): 328-31, 1990 Mar 16.
Artigo em Alemão | MEDLINE | ID: mdl-2335904

RESUMO

The following case report shows the course of disease of a 37 year old man, who showed the classical symptoms of an untreated congenital adrenal hyperplasia. But only when an adrenal tumor accidentally was detected, the endocrinological tests and the diagnosis of the congenital adrenal hyperplasia were made. By this diagnosis the planned adrenalectomy could be avoided now.


Assuntos
Hiperplasia Suprarrenal Congênita/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Hiperplasia Suprarrenal Congênita/genética , Adulto , Diagnóstico Diferencial , Triagem de Portadores Genéticos , Antígenos HLA/genética , Humanos , Masculino , Linhagem
9.
Klin Wochenschr ; 67(12): 640-4, 1989 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-2549297

RESUMO

The case of a 56-year old woman with severe Cushing's syndrome due to ovarian ACTH-production is described. Both clinical picture and biochemical pattern were consistent with the ectopic ACTH syndrome. ACTH was found by specific immunohistochemical staining in a carcinoid tumor of the patient's right ovary. In contrast, pituitary cells exhibited immunoreactive ACTH to only a minimum extent.


Assuntos
Síndrome de ACTH Ectópico/sangue , Tumor Carcinoide/complicações , Síndrome de Cushing/sangue , Neoplasias Ovarianas/complicações , Síndromes Endócrinas Paraneoplásicas/sangue , Síndrome de ACTH Ectópico/patologia , Hormônio Adrenocorticotrópico/sangue , Tumor Carcinoide/sangue , Tumor Carcinoide/patologia , Síndrome de Cushing/patologia , Feminino , Humanos , Hidrocortisona/sangue , Pessoa de Meia-Idade , Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/patologia , Ovário/patologia
10.
Ann N Y Acad Sci ; 526: 209-23, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3291683

RESUMO

Of 44 male patients with idiopathic hemochromatosis who were diagnosed at an early stage without morphological or biochemical evidence of liver disease, 25% suffered from impotence and 34% manifested glucose intolerance. Impotence was correlated with a 50% reduction in plasma testosterone, resulting from a 63% decrease in testosterone production. Testicular atrophy was caused by insufficient secretion of gonadotropins due to the selective accumulation of iron in gonadotropic cells of the pituitary gland. However, peripheral sexual hormone metabolism, in particular the conversion of androgens to estrogens, remained unaltered. It was therefore possible to employ substitution therapy successfully with testosterone in these men, and hyperestrogenism was not observed as a side effect. The pathogenetic factors in the development of diabetes mellitus in patients with idiopathic hemochromatosis include impaired insulin secretion caused by the selective deposition of iron in B-cells of the pancreas and insulin resistance due to iron accumulation in the liver. In particular, the insulin resistance is markedly improved after depletion of body iron stores by phlebotomy treatment, resulting in lower insulin requirements in patients with insulin-dependent diabetes as well as improvement of carbohydrate metabolisms in about half of the patients with non-insulin-dependent diabetes. We have concluded that hypogonadism and carbohydrate intolerance are caused by the specific distribution pattern of excess iron in the organism, accompanied by functional impairment of affected parenchymal cells.


Assuntos
Androgênios/metabolismo , Estrogênios/metabolismo , Hemocromatose/metabolismo , Insulina/metabolismo , Adulto , Metabolismo dos Carboidratos , Diabetes Mellitus/etiologia , Disfunção Erétil/etiologia , Feminização/etiologia , Gonadotropinas Hipofisárias/metabolismo , Hemocromatose/complicações , Humanos , Hipogonadismo/etiologia , Sistema Hipotálamo-Hipofisário/fisiopatologia , Secreção de Insulina , Ferro/metabolismo , Cirrose Hepática/etiologia , Masculino , Testículo/patologia , Testículo/fisiopatologia
11.
Klin Wochenschr ; 65(14): 627-33, 1987 Jul 15.
Artigo em Alemão | MEDLINE | ID: mdl-3498089

RESUMO

Adrenal tumors accidently detected by CT scan are increasingly seen in patients without clinical signs of adrenal diseases. We studied whether enhanced adrenal stimulation is of importance in the development of adrenal tumors. For this purpose 22 patients with adrenogenital syndrome (AGS) were studied by CT scan. One of these patients suffered from C-11 beta-hydroxylase-, one from C-3 beta-hydroxy steroid dehydrogenase-, and 20 from C-21-hydroxylase deficiency. The average adrenal size of these patients was 506 +/- 79 mm2 as compared to 132 +/- 8 mm2 in the controls (P less than 0.001). Only two patients with the late onset form revealed adrenal glands of normal size. There was a significant correlation between adrenal size and patients' age (P less than 0.01). Females with the simple virilizing form revealed adrenal glands larger than those of the late onset form (640 +/- 169 vs 308 +/- 56 mm2). Eighteen patients with AGS exhibited one (n = 11) or several (n = 7) adrenal tumors, the size of which was 5-9 mm in diameter in 9, 10-20 mm in 7, and more than 50 mm in 2 patients. There was a significant correlation between adrenal hyperplasia and tumor diameter (P less than 0.001). No correlation was found between tumor size and plasma concentrations of testosterone or 17-hydroxyprogesterone, patients' age at the time of diagnosis, or clinical signs of androgenization. Again, tumors were larger in females suffering from the simple virilizing form of AGS than in those with the late onset form (14.8 +/- 5.5 vs 7.7 +/- 0.8 mm).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Adenoma/patologia , Neoplasias das Glândulas Suprarrenais/patologia , Hiperplasia Suprarrenal Congênita/patologia , 17-alfa-Hidroxiprogesterona , Adenoma/enzimologia , Adolescente , Neoplasias das Glândulas Suprarrenais/enzimologia , Glândulas Suprarrenais/patologia , Hiperplasia Suprarrenal Congênita/enzimologia , Adulto , Criança , Cortisona Redutase/deficiência , Feminino , Humanos , Hidroxiprogesteronas/sangue , Masculino , Pessoa de Meia-Idade , Testosterona/sangue , Tomografia Computadorizada por Raios X
13.
Horm Res ; 25(2): 72-9, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3106178

RESUMO

The androgen receptor in fibroblasts cultured from a biopsy of scrotal skin from 1 subject with Reifenstein syndrome has been found to be normal in amount and to bind dihydrotestosterone with normal affinity but to be qualitatively abnormal as evident by thermolability and instability upon ultracentrifugation. The family study of this subject and endocrine studies document androgen resistance in the index patient and his affected uncle. These findings provide evidence for X-linkage of this disorder, and suggest that the mutations that give rise to this phenotype are probably allelic to the mutations of the androgen receptor that cause testicular feminization.


Assuntos
Ginecomastia/metabolismo , Hipospadia/metabolismo , Receptores Androgênicos/metabolismo , Adolescente , Adulto , Di-Hidrotestosterona/metabolismo , Fibroblastos/metabolismo , Hormônio Foliculoestimulante/sangue , Ginecomastia/genética , Humanos , Hipospadia/genética , Hormônio Luteinizante/sangue , Masculino , Síndrome
14.
Cancer Treat Rep ; 70(10): 1153-7, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3756937

RESUMO

In a phase II study, 38 evaluable patients with advanced progressive breast cancer were treated with 4 X 250 mg of aminoglutethimide per day without hydrocortisone supplementation. Partial remissions were observed in five patients (13%), with a median duration of 9 months (range, 7-15), and stable disease was observed in 17 patients (45%), with a median duration of 4 months (range, 2-11). The recorded side effects (CNS, cutaneous, gastrointestinal) were tolerable and transient and required drug discontinuation in only four patients. Serial determinations of serum hormone levels during aminoglutethimide treatment revealed a significant decrease in estradiol and an increase in gonadotropins, testosterone, and progesterone. No patients had adrenal insufficiency. In contrast, despite prolonged aminoglutethimide treatment and persisting hypoestrogenemia, both cortisol levels and adrenal responses to ACTH remained unaltered. It is concluded that aminoglutethimide alone is effective in the treatment of postmenopausal patients with breast cancer. Moreover, based on the present findings, a prospective randomized study is warranted to show that hydrocortisone supplementation appears to not be mandatory, either for increase in efficacy or for decrease in side effects of the treatment.


Assuntos
Aminoglutetimida/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Adulto , Idoso , Aminoglutetimida/efeitos adversos , Neoplasias Ósseas/secundário , Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Avaliação de Medicamentos , Feminino , Hormônios/sangue , Humanos , Neoplasias Pulmonares/secundário , Menopausa , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Receptores de Estrogênio/análise
15.
J Clin Chem Clin Biochem ; 24(8): 577-81, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3760788

RESUMO

A radioimmunoassay (RIA) is described for the measurement of 11 beta,17 beta-dihydroxy-4-androsten-3-one (11 beta-hydroxytestosterone) in human plasma. The reliability criteria of the new RIA were similar to those of other steroid hormone radioimmunoassays. The mean plasma 11 beta,17 beta-dihydroxy-4-androsten-3-one level for healthy young subjects was 1.31 +/- 0.32 nmol/l (means +/- SD) in males and 1.19 +/- 0.35 nmol/l in females at 8 a.m.; during the night, there was a marked decrease, and at 11 p.m. the recorded values were 0.41 +/- 0.15 nmol/l and 0.46 +/- 0.14 nmol/l, respectively. During the corticotropin stimulation test, 11 beta,17 beta-dihydroxy-4-androsten-3-one increased from 1.03 +/- 0.33 nmol/l to 1.31 +/- 0.41 nmol/l, while in dexamethasone suppression tests a decrease from 2.04 +/- 0.82 nmol/l to 0.25 +/- 0.05 nmol/l was seen. In contrast, chorionic gonadotropin administration on 3 consecutive days did not influence plasma concentrations of 11 beta,17 beta-dihydroxy-4-androsten-3-one.


Assuntos
Hidroxitestosteronas/sangue , Testosterona/análogos & derivados , Adulto , Ritmo Circadiano , Dexametasona/sangue , Humanos , Hidrocortisona/sangue , Masculino , Radioimunoensaio , Testosterona/sangue
16.
Arzneimittelforschung ; 36(6): 893-4, 1986 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-2874815

RESUMO

The chiral benzodiazepines camazepam (1) and ketazolam (2) were resolved into the enantiomers by chromatography on the optically active adsorbent poly[(S)-N-(1-cyclohexylethyl)-methacrylamide] and fractional crystallisation or repeated chromatography, respectively. The IC50 values of the isomers and of the racemates of both compounds were determined by displacement of radioactively labelled 3H-flunitrazepam and 3H-propyl-beta-carboline-carboxylate from their specific binding sites. (+)-Camazepam exhibits 14fold higher affinity compared to the (-)-enantiomer. In contrast only slight differences in the receptor affinity are observed with the ketazolam enantiomers.


Assuntos
Ansiolíticos/metabolismo , Benzodiazepinas , Benzodiazepinonas/metabolismo , Receptores de GABA-A/metabolismo , Temazepam/metabolismo , Animais , Benzodiazepinonas/isolamento & purificação , Ligação Competitiva , Encéfalo/metabolismo , Flunitrazepam/metabolismo , Técnicas In Vitro , Estereoisomerismo , Temazepam/isolamento & purificação
17.
Int J Androl ; 9(2): 123-31, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3793255

RESUMO

Male C57Bl/6J-ob/ob mice (4 months old) and their homozygous lean controls were compared with respect to pituitary LH secretion and functional parameters of purified Leydig cells in vitro. Compared with controls, obese mice showed reductions in the following parameters: Plasma testosterone levels (reduced by 57%), hCG-stimulated testosterone formation in vitro (by 31%), conversion of progesterone to androgens by Leydig cells (by 39%), and GnRH-stimulated LH secretion (by 26%). Lipid accumulation and a 37% decrease in naphthylesterase activity in the Leydig cells as well as hyperplasia of pituitary gonadotrophs were observed histochemically in obese mice. The changes in testicular endocrine function in obese mice are interpreted as consequences of pituitary dysfunction.


Assuntos
Células Intersticiais do Testículo/fisiologia , Obesidade/fisiopatologia , Hipófise/fisiopatologia , Testículo/fisiopatologia , Testosterona/biossíntese , Androstenodiona/sangue , Animais , Epididimo/patologia , Células Intersticiais do Testículo/enzimologia , Metabolismo dos Lipídeos , Hormônio Luteinizante/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos , Naftol AS D Esterase/metabolismo , Obesidade/patologia , Tamanho do Órgão , Hipófise/metabolismo , Testículo/patologia , Testosterona/sangue
18.
Steroids ; 47(4-5): 287-94, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3590240

RESUMO

Circulating human lymphocytes are known to contain specific glucocorticoid receptors. Using a competitive binding whole cell assay, we have examined the binding of [3H] dexamethasone to peripheral lymphocytes of normal male subjects. Lymphocytes were found to contain 2000-10000 glucocorticoid receptor sites/cell and the Kd value was in the range of 0.5-9 X 10(-9) M. The number and affinity of glucocorticoid receptors did not change throughout a 1-year observation time. In contrast, there was a significant diurnal variation in receptor content (38% higher at 11 p.m. than at 8 a.m.), while receptor affinity did not change.


Assuntos
Ritmo Circadiano , Linfócitos/metabolismo , Receptores de Glucocorticoides/metabolismo , Estações do Ano , Dexametasona/metabolismo , Humanos , Masculino , Ensaio Radioligante
19.
J Clin Chem Clin Biochem ; 23(12): 875-8, 1985 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-3831227

RESUMO

In order to examine whether plasma samples may be used for steroid analysis after long periods of storage, cortisol, testosterone, oestrone and oestradiol were remeasured in samples, which had been analysed 1.3-10.8 years earlier. The method for the measurement of these steroids was unchanged over this period. The results demonstrate that at a temperature of -25 degrees C steroids remained stable. Only cortisol and testosterone concentrations showed a small, insignificant decrease (6-9%) after 3 to 4 years of storage. These differences are well within the range of the precision of the method (interassay variation), which over a period of 11 years was 9.4%, 8.0%, 10.0% and 9.5% for cortisol, testosterone, oestrone and oestradiol, respectively. It is concluded that steroid hormones in human plasma are stable in our laboratory, and that they might be analysed even after more than 10 years of storage at -25 degrees C.


Assuntos
Esteroides/sangue , Preservação de Sangue , Estabilidade de Medicamentos , Estradiol/sangue , Estrona/sangue , Congelamento , Humanos , Hidrocortisona/sangue , Testosterona/sangue , Fatores de Tempo
20.
Horm Metab Res ; 17(11): 576-9, 1985 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3000907

RESUMO

The hypothesis that male diabetes mutant mice (C57Bl/KsJ-db/db) are suffering from impairment of testicular steroidogenic function and pituitary LH release was tested. A smaller postpubertal increase of testicular weight and a reduction of plasma testosterone and androstenedione levels by 65% at 17 weeks of age were most obvious from the comparison to homozygous lean controls. The ability of constant amounts of Leydig cells, either in crude interstitial cell or in purified Leydig cell suspensions, to respond to maximal doses of hCG or cyclic AMP-was reduced by at least 40% in adult diabetes mice. This defect could be attributed to a 40% decrease of steroid-17 alpha-monooxygenase activity as compared to lean mice. No differences occurred, however, if Leydig cells were submaximally stimulated. GnRH-stimulated pituitary LH release was not significantly changed. The impairment of testicular steroidogenic function in diabetes mutant mice may represent a further aspect of infertility of these animals and of diabetes mellitus.


Assuntos
Diabetes Mellitus Experimental/fisiopatologia , Camundongos Mutantes/fisiologia , Hipófise/fisiopatologia , Testículo/fisiopatologia , Animais , Bucladesina/farmacologia , Gonadotropina Coriônica/farmacologia , Células Intersticiais do Testículo/metabolismo , Hormônio Luteinizante/metabolismo , Masculino , Camundongos , Obesidade/fisiopatologia , Esteroide 17-alfa-Hidroxilase/metabolismo , Testosterona/biossíntese
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