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1.
Metabolism ; 138: 155341, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36341838

RESUMEN

OBJECTIVE: The hypothalamus is the main integrator of peripheral and central signals in the control of energy homeostasis. Its functional relevance for the effectivity of bariatric surgery is not entirely elucidated. Studying the effects of bariatric surgery in patients with hypothalamic damage might provide insight. SUMMARY BACKGROUND DATA: Prospective study to analyze the effects of bariatric surgery in patients with hypothalamic obesity (HO) vs. matched patients with common obesity (CO) with and without bariatric surgery. METHODS: 65 participants were included (HO-surgery: n = 8, HO-control: n = 10, CO-surgery: n = 12, CO-control: n = 12, Lean-control: n = 23). Body weight, levels of anorexic hormones, gut microbiota, as well as subjective well-being/health status, eating behavior, and brain activity (via functional MRI) were evaluated. RESULTS: Patients with HO lost significantly less weight after bariatric surgery than CO-participants (total body weight loss %: 5.5 % vs. 26.2 %, p = 0.0004). After a mixed meal, satiety and abdominal fullness tended to be lowest in HO-surgery and did not correlate with levels of GLP-1 or PYY. Levels of PYY (11,151 ± 1667 pmol/l/h vs. 8099 ± 1235 pmol/l/h, p = 0.028) and GLP-1 (20,975 ± 2893 pmol/l/h vs. 13,060 ± 2357 pmol/l/h, p = 0.009) were significantly higher in the HO-surgery vs. CO-surgery group. Abundance of Enterobacteriaceae and Streptococcus was increased in feces of HO and CO after bariatric surgery. Comparing HO patients with lean-controls revealed an increased activation in insula and cerebellum to viewing high-caloric foods in left insula and cerebellum in fMRI. CONCLUSIONS: Hypothalamic integrity is necessary for the effectiveness of bariatric surgery in humans. Peripheral changes after bariatric surgery are not sufficient to induce satiety and long-term weight loss in patients with hypothalamic damage.


Asunto(s)
Cirugía Bariátrica , Derivación Gástrica , Enfermedades Hipotalámicas , Humanos , Estudios Prospectivos , Estudios Transversales , Pérdida de Peso/fisiología , Obesidad/cirugía , Péptido 1 Similar al Glucagón , Hipotálamo
2.
Front Endocrinol (Lausanne) ; 12: 712107, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34475850

RESUMEN

Background: Treatment options for poorly differentiated (PDTC) and anaplastic (ATC) thyroid carcinoma are unsatisfactory and prognosis is generally poor. Lenvatinib (LEN), a multi-tyrosine kinase inhibitor targeting fibroblast growth factor receptors (FGFR) 1-4 is approved for advanced radioiodine refractory thyroid carcinoma, but response to single agent is poor in ATC. Recent reports of combining LEN with PD-1 inhibitor pembrolizumab (PEM) are promising. Materials and Methods: Primary ATC (n=93) and PDTC (n=47) tissue samples diagnosed 1997-2019 at five German tertiary care centers were assessed for PD-L1 expression by immunohistochemistry using Tumor Proportion Score (TPS). FGFR 1-4 mRNA was quantified in 31 ATC and 14 PDTC with RNAscope in-situ hybridization. Normal thyroid tissue (NT) and papillary thyroid carcinoma (PTC) served as controls. Disease specific survival (DSS) was the primary outcome variable. Results: PD-L1 TPS≥50% was observed in 42% of ATC and 26% of PDTC specimens. Mean PD-L1 expression was significantly higher in ATC (TPS 30%) than in PDTC (5%; p<0.01) and NT (0%, p<0.001). 53% of PDTC samples had PD-L1 expression ≤5%. FGFR mRNA expression was generally low in all samples but combined FGFR1-4 expression was significantly higher in PDTC and ATC compared to NT (each p<0.001). No impact of PD-L1 and FGFR 1-4 expression was observed on DSS. Conclusion: High tumoral expression of PD-L1 in a large proportion of ATCs and a subgroup of PDTCs provides a rationale for immune checkpoint inhibition. FGFR expression is low thyroid tumor cells. The clinically observed synergism of PEM with LEN may be caused by immune modulation.


Asunto(s)
Antígeno B7-H1/antagonistas & inhibidores , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Carcinoma Anaplásico de Tiroides/tratamiento farmacológico , Neoplasias de la Tiroides/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados/farmacología , Antineoplásicos , Antineoplásicos Inmunológicos , Antígeno B7-H1/análisis , Evaluación Preclínica de Medicamentos/métodos , Femenino , Alemania , Humanos , Masculino , Persona de Mediana Edad , Compuestos de Fenilurea/farmacología , Quinolinas/farmacología , ARN Mensajero/análisis , Receptores de Factores de Crecimiento de Fibroblastos/genética , Carcinoma Anaplásico de Tiroides/química , Carcinoma Anaplásico de Tiroides/patología , Neoplasias de la Tiroides/química , Neoplasias de la Tiroides/patología
3.
Thyroid ; 31(10): 1531-1541, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34405734

RESUMEN

Background: The management of patients with locally advanced or metastatic differentiated thyroid cancer (DTC) that is refractory to radioiodine (RAI) remains a therapeutic challenge. The multi-tyrosine kinase inhibitors (TKIs) sorafenib and lenvatinib have been approved based on phase 3 clinical trials. Patients and Methods: We aimed at describing the efficacy and safety of TKI treatment of RAI-refractory DTC in a real-world setting at six German referral centers. One hundred and one patients with locally advanced or metastatic RAI-refractory DTC treated with sorafenib, lenvatinib, and/or pazopanib were included. Progression-free survival (PFS) and overall survival (OS) probabilities were estimated by using the Kaplan-Meier method. Results: Ninety-seven of 101 patients had progressive disease before TKI initiation. The median PFS for first-line treatment with sorafenib (n = 33), lenvatinib (n = 53), and pazopanib (n = 15) was 9 (95% confidence interval 5.2-12.8), 12 (4.4-19.6), and 12 months (4.4-19.6), respectively. The median OS for first-line treatment was 37 (10-64) for sorafenib, 47 (15.5-78.5) for lenvatinib, and 34 months (20.2-47.8) for pazopanib. Serious complications (e.g., hemorrhage, acute coronary syndrome, and thrombosis/venous thromboembolism) occurred in 16 out of 75 (21%) patients taking lenvatinib, in 3 out of 42 (7%) patients taking sorafenib, and in 3 out of 24 (13%) patients taking pazopanib. Conclusions: Sorafenib, lenvatinib, and pazopanib are effective treatment options in the majority of patients with RAI-refractory DTC. The PFS and six-month survival rate in patients treated with lenvatinib und pazopanib appear to compare favorably with sorafenib in the first-line treatment setting. However, a more advanced disease stage at treatment initiation in sorafenib- and pazopanib-treated patients in the era before TKI-approval and the retrospective nature of this study precludes a direct comparison of TKIs.


Asunto(s)
Indazoles/uso terapéutico , Radioisótopos de Yodo/uso terapéutico , Compuestos de Fenilurea/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirimidinas/uso terapéutico , Quinolinas/uso terapéutico , Radiofármacos/uso terapéutico , Terapia Recuperativa/métodos , Sorafenib/uso terapéutico , Sulfonamidas/uso terapéutico , Neoplasias de la Tiroides/tratamiento farmacológico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Humanos , Indazoles/efectos adversos , Indazoles/farmacología , Masculino , Persona de Mediana Edad , Compuestos de Fenilurea/efectos adversos , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/efectos adversos , Pirimidinas/efectos adversos , Pirimidinas/farmacología , Quinolinas/efectos adversos , Quinolinas/farmacología , Estudios Retrospectivos , Seguridad , Sorafenib/efectos adversos , Sorafenib/farmacología , Sulfonamidas/efectos adversos , Sulfonamidas/farmacología , Neoplasias de la Tiroides/mortalidad , Resultado del Tratamiento , Adulto Joven
4.
BMC Endocr Disord ; 21(1): 11, 2021 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-33419423

RESUMEN

BACKGROUND: Endogenous Cushing's syndrome (CS) results in increased cardiovascular (CV) morbidity and mortality. So far, most studies focussed on distinct disease entities rather than the integrity of the CV system. We here describe the design of the Cardiovascular Status in Endogenous Cortisol Excess Study (CV-CORT-EX), a study aiming to comprehensively investigate the health status of patients with endogenous CS (with a particular focus on CV phenotypes, biochemical aspects, quality of life, and psychosocial status). METHOD: A prospective non-interventional cohort study performed at a German tertiary referral centre. At the time of enrolment, patients will be categorised as: (1) newly diagnosed overt CS, (2) recurrent overt CS, (3) CS in remission, (4) presence of mild autonomous cortisol excess (MACE). The target cohorts will be n = 40 (groups 1 + 2), n = 80 (group 3), and n = 20 (group 4). Patients with overt CS at the time of enrolment will be followed for 12 months after remission (with re-evaluations after 6 and 12 months). At each visit, patients will undergo transthoracic echocardiography, cardiac magnetic resonance imaging, 24-h electrocardiogram, 24-h blood pressure measurement, and indirect evaluation of endothelial function. Furthermore, a standardised clinical investigation, an extensive biochemical workup, and a detailed assessment of quality of life and psychosocial status will be applied. Study results (e.g. cardiac morphology and function according to transthoracic echocardiography and cardiac magnetic resonance imaging; e.g. prevalence of CV risk factors) from patients with CS will be compared with matched controls without CS derived from two German population-based studies. DISCUSSION: CV-CORT-EX is designed to provide a comprehensive overview of the health status of patients with endogenous CS, mainly focussing on CV aspects, and the holistic changes following remission. TRAIL REGISTRATION: ClinicalTrials.gov ( https://clinicaltrials.gov/ ) NCT03880513, registration date: 19 March 2019 (retrospectively registered). Protocol Date: 28 March 2014, Version 2.


Asunto(s)
Enfermedades Cardiovasculares/diagnóstico , Síndrome de Cushing/diagnóstico , Hidrocortisona/sangre , Adulto , Anciano , Presión Sanguínea , Enfermedades Cardiovasculares/sangre , Estudios de Cohortes , Síndrome de Cushing/sangre , Ecocardiografía , Electrocardiografía , Femenino , Estudios de Seguimiento , Alemania , Corazón/diagnóstico por imagen , Humanos , Hipertrofia Ventricular Izquierda/complicaciones , Hipertrofia Ventricular Izquierda/diagnóstico , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Recurrencia , Factores de Riesgo , Conducta Social
5.
Nutrients ; 14(1)2021 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-35010991

RESUMEN

BACKGROUND: The hypothalamus is an important brain region for the regulation of energy balance. Roux-en-Y gastric bypass (RYGB) surgery and gut hormone-based treatments are known to reduce body weight, but their effects on hypothalamic gene expression and signaling pathways are poorly studied. METHODS: Diet-induced obese male Wistar rats were randomized into the following groups: RYGB, sham operation, sham + body weight-matched (BWM) to the RYGB group, osmotic minipump delivering PYY3-36 (0.1 mg/kg/day), liraglutide s.c. (0.4 mg/kg/day), PYY3-36 + liraglutide, and saline. All groups (except BWM) were kept on a free choice of high- and low-fat diets. Four weeks after interventions, hypothalami were collected for RNA sequencing. RESULTS: While rats in the RYGB, BWM, and PYY3-36 + liraglutide groups had comparable reductions in body weight, only RYGB and BWM treatment had a major impact on hypothalamic gene expression. In these groups, hypothalamic leptin receptor expression as well as the JAK-STAT, PI3K-Akt, and AMPK signaling pathways were upregulated. No significant changes could be detected in PYY3-36 + liraglutide-, liraglutide-, and PYY-treated groups. CONCLUSIONS: Despite causing similar body weight changes compared to RYGB and BWM, PYY3-36 + liraglutide treatment does not impact hypothalamic gene expression. Whether this striking difference is favorable or unfavorable to metabolic health in the long term requires further investigation.


Asunto(s)
Hormonas Gastrointestinales/farmacología , Hipotálamo/metabolismo , Liraglutida/farmacología , Fragmentos de Péptidos/farmacología , Péptido YY/farmacología , Transcriptoma/efectos de los fármacos , Animales , Peso Corporal , Restricción Calórica , Modelos Animales de Enfermedad , Metabolismo Energético , Derivación Gástrica , Expresión Génica/efectos de los fármacos , Masculino , Obesidad , Ratas , Ratas Wistar , Transducción de Señal/efectos de los fármacos
6.
Dtsch Med Wochenschr ; 145(3): 135-139, 2020 02.
Artículo en Alemán | MEDLINE | ID: mdl-32018284

RESUMEN

While effects of vitamin D on bone metabolism are widely acknowledged, many questions regarding extraskeletal actions of vitamin D have emerged. In-vitro data show the expression of the nuclear vitamin D receptor in a variety of different extraskeletal tissues. However, it's relevance in clinical practice is still unclear. Numerous observational studies suggest that low vitamin D levels might represent a risk factor for several diseases, including cancer, cardiovascular disease and diabetes. Very recently, several randomized controlled trials assessing the effect of vitamin D supplementation on prevention of different diseases have been published with disappointing results. In this review we focus on assessment of vitamin D status, as well as results of currently published randomized controlled trials on vitamin D and disease prevention.


Asunto(s)
Deficiencia de Vitamina D , Vitamina D , Enfermedades Cardiovasculares/prevención & control , Humanos , Neoplasias/prevención & control , Receptores de Calcitriol/metabolismo , Factores de Riesgo
7.
Proc Natl Acad Sci U S A ; 116(44): 22269-22274, 2019 10 29.
Artículo en Inglés | MEDLINE | ID: mdl-31611400

RESUMEN

Adrenocortical carcinomas (ACCs) are rare and highly malignant cancers associated with poor survival of patients. Currently, mitotane, a nonspecific derivative of the pesticide DDT (1,1-(dichlorobiphenyl)-2,2-dichloroethane), is used as the standard treatment, but its mechanism of action in ACCs remains elusive. Here we demonstrate that the human ACC NCI-H295R cell line is remarkably sensitive to induction of ferroptosis, while mitotane does not induce this iron-dependent mode of regulated necrosis. Supplementation with insulin, transferrin, and selenium (ITS) is commonly used to keep NCI-H295R cells in cell culture. We show that this supplementation prevents spontaneous ferroptosis, especially when it contains polyunsaturated fatty acids (PUFAs), such as linoleic acid. Inhibitors of apoptosis (zVAD, emricasan) do not prevent the mitotane-induced cell death but morphologically prevent membrane blebbing. The expression of glutathione peroxidase 4 (GPX4) in H295R cells, however, is significantly higher when compared to HT1080 fibrosarcoma cells, suggesting a role for ferroptosis. Direct inhibition of GPX4 in H295R cells led to high necrotic populations compared to control, while cotreatment with ferrostatin-1 (Fer-1) completely reverted ferroptosis. Interestingly, the analysis of public databases revealed that several key players of the ferroptosis pathway are hypermethylated and/or mutated in human ACCs. Finally, we also detected that growth hormone-releasing hormone (GHRH) antagonists, such as MIA602, kill H295R cells in a nonapoptotic manner. In summary, we found elevated expression of GPX4 and higher sensitivity to ferroptosis in ACCs. We hypothesize that instead of treatment with mitotane, human adrenocortical carcinomas may be much more sensitive to induction of ferroptosis.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/metabolismo , Carcinoma Corticosuprarrenal/metabolismo , Ferroptosis/efectos de los fármacos , Células 3T3 , Animales , Apoptosis/efectos de los fármacos , Células HEK293 , Células HT29 , Humanos , Insulina/metabolismo , Hierro/metabolismo , Ácido Linoleico/metabolismo , Ratones , Mitotano/toxicidad , Fosfolípido Hidroperóxido Glutatión Peroxidasa/genética , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Selenio/metabolismo , Sermorelina/análogos & derivados , Sermorelina/farmacología , Transferrina/metabolismo
8.
Ann Surg Oncol ; 26(2): 531-538, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30443830

RESUMEN

BACKGROUND: In the surgical treatment of adrenocortical carcinoma (ACC), lymphadenectomy may improve oncologic outcome. However, patterns of metastatic lymphatic spread in ACC are unknown. METHODS: Clinical data of patients included in the European Network for the Study of Adrenal Tumors (ENSAT) registry were retrospectively reviewed. Inclusion criteria were: nonmetastatic ACC, complete resection of the primary tumor, a disease-free time of > 3 months, and lymph node metastases as the first disease relapse. The retroperitoneal lymphatic drainage area was evaluated by using follow-up imaging. RESULTS: Of 971 patients from the ENSAT registry, 56 patients were included. In left-sided ACC (n = 36), lymphatic recurrence was detected in the left renal hilum (50%), in the perirenal fat tissue cranial to the renal hilum (ventral, 47%; dorsal, 55%), para-aortic (47%), interaorto-caval (22%), and/or in the perirenal fat tissue caudal to the renal hilum (ventral, 20%; dorsal, 17%). In right-sided ACC (n = 20), lymph node metastases were detected in the perirenal fat tissue cranial to the renal hilum (dorsal, 55%; ventral, 45%), interaorto-caval (35%), in the area of the right renal artery (10%), and/or paracaval (15%). Patients with right-sided ACC showed left-paraaortic lymph node recurrences in 10% of cases. CONCLUSION: Metastatic lymphatic spread appears to be more extensive than previously thought. The distribution pattern of lymph node metastases described in our study could be used as a guide for a more extended lymph node dissection.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/patología , Carcinoma Corticosuprarrenal/patología , Neoplasias Renales/secundario , Escisión del Ganglio Linfático/mortalidad , Recurrencia Local de Neoplasia/patología , Neoplasias de la Corteza Suprarrenal/cirugía , Carcinoma Corticosuprarrenal/cirugía , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Renales/cirugía , Metástasis Linfática , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/cirugía , Estadificación de Neoplasias , Estudios Retrospectivos , Tasa de Supervivencia
9.
Horm Cancer ; 7(5-6): 345-355, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27631436

RESUMEN

Mitotane is the only drug approved for treatment of the orphan disease adrenocortical carcinoma (ACC) and was recently shown to be the first clinically used drug acting through endoplasmic reticulum (ER)-stress induced by toxic lipids. Since mitotane has limited clinical activity as monotherapy, we here study the potential of activating ER-stress through alternative pathways. The single reliable NCI-H295 cell culture model for ACC was used to study the impact MG132, bortezomib (BTZ) and carfilzomib (CFZ) on mRNA and protein expression of ER-stress markers, cell viability and steroid hormone secretion. We found all proteasome inhibitors alone to trigger expression of mRNA (spliced X-box protein 1, XBP1) and protein markers indicative of the inositol-requiring enzyme 1 (IRE1) dependent pathway of ER-stress but not phosphorylation of eukaryotic initiation factor 2α (eIF2α), a marker of the PRKR-like endoplasmic reticulum kinase (PERK)-dependent pathway. Whereas mitotane alone activated both pathways, combination of BTZ and CFZ with low-dose mitotane blocked mitotane-induced eIF2α phosphorylation but increased XBP1-mRNA splicing indicating that proteasome inhibitors can commit signalling towards a single ER-stress pathway in ACC cells. By applying the median effect model of drug combinations using cell viability as a read out, we determined significant drug synergism between mitotane and both BTZ and CFZ. In conclusion, combination of mitotane with activators of ER-stress through the unfolded protein response is synergistic in an ACC cell culture model. Since proteasome inhibitors are readily available clinically, they are attractive candidates to study for ACC treatment in clinical trials in combination with mitotane.


Asunto(s)
Neoplasias de la Corteza Suprarrenal/genética , Carcinoma Corticosuprarrenal/genética , Antineoplásicos Hormonales/farmacología , Endorribonucleasas/genética , Factor 2 Eucariótico de Iniciación/metabolismo , Mitotano/farmacología , Inhibidores de Proteasoma/farmacología , Proteínas Serina-Treonina Quinasas/genética , Proteína 1 de Unión a la X-Box/genética , Neoplasias de la Corteza Suprarrenal/tratamiento farmacológico , Neoplasias de la Corteza Suprarrenal/metabolismo , Carcinoma Corticosuprarrenal/tratamiento farmacológico , Carcinoma Corticosuprarrenal/metabolismo , Bortezomib/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Quimioterapia Combinada , Estrés del Retículo Endoplásmico/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Leupeptinas/farmacología , Oligopéptidos/farmacología , Fosforilación
10.
J Clin Endocrinol Metab ; 100(5): E776-82, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25763608

RESUMEN

CONTEXT: Insulinomas represent pancreatic neuroendocrine neoplasms that cause severe morbidity attributed to their often pronounced endocrine activity. Apart from hereditary forms such as multiple endocrine neoplasia type 1 (MEN-1), genetic causes for sporadic insulinoma development had remained obscure until recently. Applying next-generation sequencing methods, disease-causing genetic alterations have been identified in various endocrine tumors. OBJECTIVE AND DESIGN: Paired tumor and blood DNA from eight patients with sporadic insulinomas (five females and two malignant tumors) were analyzed by whole-exome sequencing. After this initial analysis, Ying Yang 1 (YY1) mutation status was assessed in a larger cohort of 39 additional insulinomas (including eight malignant and one liver metastasis) from three German hospitals by targeted sequencing. The mutation status was correlated with various clinical parameters. RESULTS: A range of one to 12 somatic genetic variants were identified by exome sequencing. A recurrent somatic Thr372Arg YY1 point mutation was detected in two patients of the initial cohort and four patients of the second cohort (total, six of 47; 13%). The presence of the mutation was associated with a trend toward higher age (63.5 y; IQR, 48.0-74.0 vs 45.0 y; IQR, 33.0-63.0; P = .05), and all affected patients were females (six of six; P = .04). All other clinical parameters, including the presence of malignancy and metastatic spread, tumor localization, and hypoglycemic episodes were not different between YY1-mutated and nonmutated tumor carriers. CONCLUSIONS: The somatic Thr372Arg YY1 mutation is a relevant finding in female patients with sporadic insulinomas. The prevalence of this mutation in this Caucasian population is considerably lower compared to that of a recently described Asian cohort.


Asunto(s)
Insulinoma/genética , Mutación , Neoplasias Pancreáticas/genética , Factor de Transcripción YY1/genética , Adulto , Anciano , Exoma , Femenino , Humanos , Insulinoma/patología , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/patología
11.
J Clin Endocrinol Metab ; 94(8): 2970-4, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19491231

RESUMEN

OBJECTIVE: The objectives of the study was to compare pentagastrin- and calcium-stimulated serum human calcitonin (hCT) levels for nonsmoking healthy adults without evidence of thyroid disorders and determine reference ranges of basal and pentagastrin- and calcium-stimulated serum hCT levels. DESIGN: This was a healthy volunteer study including within-group and intergroup comparisons. SETTING: The study was conducted at a tertiary referral center. SUBJECTS: Subjects included 50 healthy, nonsmoking volunteers (25 female; aged 22-57 yr) without evidence of thyroid abnormality. INTERVENTIONS: hCT was measured using a calcitonin two-site automated chemiluminescent immunometric assay (the most common hCT assay in clinical practice) in serum samples obtained before and 2, 5, and 15 min after iv stimulation using pentagastrin, 0.5 microg/kg body weight, or calcium gluconate, 2.5 mg/kg. MAIN OUTCOME MEASURES: Reference ranges for basal, unstimulated, and pentagastrin- or calcium-stimulated hCT and pentagastrin and calcium tolerability in healthy adults were measured. RESULTS: The 95th percentile basal hCT values did not differ between males and females (5.0 vs. 5.7 pg/ml). The 95th percentile maximal stimulated hCT values rose distinctly after pentagastrin (peak men, 37.8 pg/ml; women, 26.2 pg/ml) and even more so after calcium (peak men, 131.1 pg/ml, women, 90.2 pg/ml). No hCT increase was detected in four of 25 men and 12 of 25 women after pentagastrin vs. none of 24 men and two of 18 women after calcium. Calcium was associated with fewer and less intense adverse effects than was pentagastrin. CONCLUSION: High-dose calcium is a more potent and better-tolerated hCT stimulator than is pentagastrin. The reference ranges for basal and stimulated hCT established via automated chemiluminescent assay were lower than those reported for other assays.


Asunto(s)
Calcitonina/sangre , Calcio/farmacología , Pentagastrina/farmacología , Adulto , Femenino , Humanos , Mediciones Luminiscentes , Masculino , Persona de Mediana Edad , Valores de Referencia , Caracteres Sexuales
12.
J Endocrinol ; 190(2): 515-25, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16899584

RESUMEN

Pro-opiomelanocortin (POMC) is a polypeptide precursor that undergoes extensive processing to yield a range of peptides with biologically diverse functions. POMC-derived ACTH is vital for normal adrenal function and the melanocortin alpha-MSH plays a key role in appetite control and energy homeostasis. However, the roles of peptide fragments derived from the highly conserved N-terminal region of POMC are less well characterized. We have used mice with a null mutation in the Pomc gene (Pomc(-/-)) to determine the in vivo effects of synthetic N-terminal 1-28 POMC, which has been shown previously to possess adrenal mitogenic activity. 1-28 POMC (20 mug) given s.c. for 10 days had no effect on the adrenal cortex of Pomc(-/-) mice, with resultant cortical morphology and plasma corticosterone levels being indistinguishable from sham treatment. Concurrent administration of 1-28 POMC and 1-24 ACTH (30 mug/day) resulted in changes identical to 1-24 ACTH treatment alone, which consisted of upregulation of steroidogenic enzymes, elevation of corticosterone levels, hypertrophy of the zona fasciculate, and regression of the X-zone. However, treatment of corticosterone-depleted Pomc(-/-) mice with 1-28 POMC reduced cumulative food intake and total body weight. These anorexigenic effects were ameliorated when the peptide was administered to Pomc(-/-) mice with circulating corticosterone restored either to a low physiological level by corticosterone-supplemented drinking water (CORT) or to a supraphysiological level by concurrent 1-24 ACTH administration. Further, i.c.v. administration of 1-28 POMC to CORT-treated Pomc(-/-) mice had no effect on food intake or body weight. In wild-type mice, the effects of 1-28 POMC upon food intake and body weight were identical to sham treatment, but 1-28 POMC was able to ameliorate the hyperphagia induced by concurrent 1-24 ACTH treatment. In a mouse model which lacks all endogenous POMC peptides, s.c. treatment with synthetic 1-28 POMC alone can reduce food intake and body weight, but has no impact upon adrenal growth or steroidogenesis.


Asunto(s)
Glándulas Suprarrenales/efectos de los fármacos , Hormona Adrenocorticotrópica/farmacología , Peso Corporal/efectos de los fármacos , Ingestión de Alimentos/efectos de los fármacos , Fragmentos de Péptidos/administración & dosificación , Proopiomelanocortina/administración & dosificación , Glándulas Suprarrenales/crecimiento & desarrollo , Hormona Adrenocorticotrópica/análisis , Hormona Adrenocorticotrópica/metabolismo , Animales , Recuento de Células , Proliferación Celular , Femenino , Immunoblotting/métodos , Ratones , Ratones Noqueados , Proopiomelanocortina/genética , Proopiomelanocortina/metabolismo
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