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1.
Neuroscience ; 314: 47-63, 2016 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-26633263

RESUMEN

Microglial activation results in profound morphological, functional and gene expression changes that affect the pro- and anti-inflammatory mechanisms of these cells. Although statins have beneficial effects on inflammation, they have not been thoroughly investigated for their ability to affect microglial functions. Therefore the effects of rosuvastatin, one of the most commonly prescribed drugs in cardiovascular therapy, either alone or in combination with bacterial lipopolysaccharide (LPS), were profiled in pure microglial cultures derived from the forebrains of 18-day-old rat embryos. To reveal the effects of rosuvastatin on a number of pro- and anti-inflammatory mechanisms, we performed morphometric, functional and gene expression studies relating to cell adhesion and proliferation, phagocytosis, pro- and anti-inflammatory cytokine (IL-1ß, tumor necrosis factor α (TNF-α) and IL-10, respectively) production, and the expression of various inflammation-related genes, including those related to the above morphological parameters and cellular functions. We found that microglia could be an important therapeutic target of rosuvastatin. In unchallenged (control) microglia, rosuvastatin inhibited proliferation and cell adhesion, but promoted microspike formation and elevated the expression of certain anti-inflammatory genes (Cxcl1, Ccl5, Mbl2), while phagocytosis or pro- and anti-inflammatory cytokine production were unaffected. Moreover, rosuvastatin markedly inhibited microglial activation in LPS-challenged cells by affecting both their morphology and functions as it inhibited LPS-elicited phagocytosis and inhibited pro-inflammatory cytokine (IL-1ß, TNF-α) production, concomitantly increasing the level of IL-10, an anti-inflammatory cytokine. Finally, rosuvastatin beneficially and differentially affected the expression of a number of inflammation-related genes in LPS-challenged cells by inhibiting numerous pro-inflammatory and stimulating several anti-inflammatory genes. Since the microglia could elicit pro-inflammatory responses leading to neurodegeneration, it is important to attenuate such mechanisms and promote anti-inflammatory properties, and develop prophylactic therapies. By beneficially regulating both pro- and anti-inflammatory microglial functions, rosuvastatin may be considered as a prophylactic agent in the prevention of inflammation-related neurological disorders.


Asunto(s)
Antiinflamatorios/farmacología , Inflamación/metabolismo , Inflamación/fisiopatología , Microglía/efectos de los fármacos , Microglía/metabolismo , Rosuvastatina Cálcica/farmacología , Animales , Adhesión Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Citocinas/metabolismo , Expresión Génica/efectos de los fármacos , Inflamación/inducido químicamente , Inflamación/genética , Mediadores de Inflamación/metabolismo , Lipopolisacáridos , Microglía/citología , Microglía/fisiología , Fagocitosis/efectos de los fármacos , Prosencéfalo/citología , Ratas , Ratas Sprague-Dawley
2.
Cell Mol Biol (Noisy-le-grand) ; 51(2): 177-86, 2005 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-16171553

RESUMEN

Thyroid nodules are common. It would very helpful if genetic markers that can diagnose malignancy from fine needle aspiration samples were available. Few such markers has been thus identified and none are specific. Large panels of potential markers can be screened by microarray technology. Studies done to date have concentrated on single tumor types and thus provide no help in identifying tumor subtype specific markers. To that end we have studied gene profiles of 5 types of benign and malignant thyroid nodular tissue (multinodular goiter, follicular adenoma, papillary and follicular carcinomas). We have identified 195 genes whose differential expression clustered into clinically relevant groups. Twenty-eight genes were selected for further confirmation using real time quantitative polymerase chain reaction. Despite the differences in the microarray panels used, we confirmed the differential regulation of 12 genes previously reported in thyroid cancer, although we found the expression of several genes to be regulated in other histological tumor subtypes than originally described. We found, PCSK2, TRIB1, RAP1 GA1 to be specifically overexpressed in follicular cancer and S100A4 and GK2 in papillary carcinoma. SERP1, RNASE 2 and STATA5 were suppressed in papillary thyroid cancer. We have thus identified new potential markers specific to malignant thyroid tumors. It is apparent that a range of nodular thyroid tissue using large tumor sample numbers is necessary to establish robust markers for malignancy and to categorize tumors on the basis of small tumor samples.


Asunto(s)
Perfilación de la Expresión Génica , Genes Relacionados con las Neoplasias , Neoplasias de la Tiroides/diagnóstico , Neoplasias de la Tiroides/genética , Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Folicular/genética , Adenocarcinoma Folicular/fisiopatología , Adenoma/diagnóstico , Adenoma/genética , Adenoma/fisiopatología , Biomarcadores de Tumor/genética , Biopsia con Aguja Fina , Carcinoma Papilar/diagnóstico , Carcinoma Papilar/genética , Carcinoma Papilar/fisiopatología , Regulación Neoplásica de la Expresión Génica , Bocio Nodular/diagnóstico , Bocio Nodular/genética , Bocio Nodular/fisiopatología , Humanos , Microscopía Confocal , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa , Neoplasias de la Tiroides/fisiopatología
3.
Biomed Res Int ; 2015: 968981, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26075279

RESUMEN

Combination therapy of bortezomib with other chemotherapeutics is an emerging treatment strategy. Since both curcumin and bortezomib inhibit NF-κB, we tested the effects of their combination on leukemia cells. To improve potency, a novel Mannich-type curcumin derivative, C-150, was synthesized. Curcumin and its analogue showed potent antiproliferative and apoptotic effects on the human leukemia cell line, HL60, with different potency but similar additive properties with bortezomib. Additive antiproliferative effects were correlated well with LPS-induced NF-κB inhibition results. Gene expression data on cell cycle and apoptosis related genes, obtained by high-throughput QPCR, showed that curcumin and its analogue act through similar signaling pathways. In correlation with in vitro results similar additive effect could be obsereved in SCID mice inoculated systemically with HL60 cells. C-150 in a liposomal formulation given intravenously in combination with bortezomib was more efficient than either of the drugs alone. As our novel curcumin analogue exerted anticancer effects in leukemic cells at submicromolar concentration in vitro and at 3 mg/kg dose in vivo, which was potentiated by bortezomib, it holds a great promise as a future therapeutic agent in the treatment of leukemia alone or in combination.


Asunto(s)
Apoptosis/efectos de los fármacos , Bortezomib/farmacología , Curcumina/farmacología , Leucemia/tratamiento farmacológico , Leucemia/metabolismo , Animales , Curcumina/análogos & derivados , Células HL-60 , Humanos , Leucemia/patología , Ratones , Ratones SCID , Ensayos Antitumor por Modelo de Xenoinjerto
4.
Am J Clin Nutr ; 31(9): 1510-4, 1978 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-685867

RESUMEN

The intake of crude fiber in the American diet was assessed for 7 time periods between 1909 and 1975 using food consumption and composition tables. Crude fiber intake dropped 28% from 6.8 g/day in 1909 to 4.9 g/day in 1957 to 1959 and has remained at that level until the present. The intake of fiber from vegetables has remained relatively constant from 1909 to 1975 while potatoes, fruit, cereals, dry peas, and dry bean consumption have declined. The trends shown for crude fiber consumption in the United States support the hypothesis that fiber intake has decreased coincidentally with increases in degenerative diseases.


Asunto(s)
Celulosa , Dieta/normas , Fibras de la Dieta , Plantas Comestibles , Grano Comestible , Frutas , Humanos , Nueces , Factores de Tiempo , Estados Unidos , Verduras
5.
Am J Clin Nutr ; 33(3): 677-86, 1980 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6986763

RESUMEN

The apparent and true digestibilities of the same preparations of six proteins (spray dried whole egg, cottage cheese, canned tuna, peanut flour, soy isolate, and wheat gluten) were estimated in four to five men and in rats and compared to estimates of digestibility from three different in vitro enzymic digestion procedures. For all six proteins, the correlation coefficient was 0.46 between true digestibility in humans and in rats; with values for tuna excluded, r = 0.96. With all six proteins, none of the in vitro values was significantly correlated with values from humans or rats. However, with either the three animal proteins alone or the three plant proteins alone, correlations were high (r greater than 0.90) between one or more of the in vitro estimates and the observed true or apparent human and rat digestibilities. The differences in the relationship between enzymic digestion estimates and the human digestibility estimates for plant or animal proteins suggest that for accurate prediction of protein digestibility in humans by these enzymic methods, different equations would have to be used for plant and animal proteins. For protein sources containing both plant and animal protein, use of the in vitro enzymic procedures would give only an approximate estimate of digestibility in humans.


Asunto(s)
Proteínas en la Dieta/metabolismo , Endopeptidasas/metabolismo , Adulto , Animales , Arachis , Queso , Digestión , Huevos , Humanos , Masculino , Carne , Persona de Mediana Edad , Proteínas de Plantas/metabolismo , Ratas , Glycine max , Triticum , Atún
6.
Biotechniques ; 33(4): 898-900, 902, 904, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12398199

RESUMEN

In DNA microarray technology, repeatability and reliability are very important to compare multiple RNA samplesfrom different experiments. The application of common or universal RNA as a standard control equalizes the differences in hybridization parameters and array variations. For this purpose, high-quality reference RNA is necessary in bulk amounts. A novel approach was developed to get milligrams of sense or antisense RNA, starting from micrograms of pooled total RNA from different cell lines, tissues, or organisms. This method is inexpensive and allows further labeling procedures using poly(dT) or random oligomers as primers. In addition, amplified, sense reference RNA is suitable for standard labeling protocols, while the antisense reference RNA can be used with antisense RNA from the linear sample amplification method. Here we produced universal RNA for human, rat, and alfalfa and demonstrated the quality using specific cDNA microarrays.


Asunto(s)
Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , ARN/aislamiento & purificación , Animales , Secuencia de Bases , Humanos , Hibridación de Ácido Nucleico , Reacción en Cadena de la Polimerasa , Ratas
7.
Biochem Pharmacol ; 47(4): 699-709, 1994 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-7907473

RESUMEN

The metabolism of the endogenous brain peptides Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) and MIF-1 (Pro-Leu-Gly-NH2) was determined by HPLC after incubation of the tritiated peptides in human and rat plasma. Degradation of Tyr-MIF-1 was rapid in the plasma from both species, in contrast to the slightly delayed degradation of MIF-1 in rat plasma and the extremely prolonged persistence of MIF-1 in human plasma. In rat plasma, more than half of the intact Tyr-MIF-1 and MIF-1 was degraded within 5 min, in contrast to the 5 days required for 50% degradation of MIF-1 in human plasma at 37 degrees. To slow the rapid rate of metabolism, studies were then performed at 0 degree. Incubation of Tyr-MIF-1 in human plasma at 0 degree for 2 hr resulted in HPLC identification of more Tyr-Pro than Tyr at all times. At 0 degree in rat plasma, however, more Tyr than Tyr-Pro was formed after the first 5 min of incubation of the Tyr-MIF-1 that was labeled on the Tyr. This raised the possibility that the tetrapeptide Tyr-MIF-1 might be serving as a precursor of the tripeptide MIF-1. Incubation of Tyr-MIF-1 tritiated at the Pro under the same conditions with and without Tyr-MIF-1 tritiated at the Tyr showed that Tyr-Pro, not MIF-1, was the predominant degradation product of Tyr-MIF-1. In addition to the metabolism of Tyr-MIF-1 being slower at lower temperatures, it was also slowed by some enzyme inhibitors. After 10 min of incubation at 37 degrees, EDTA appeared to be more effective than bestatin, p-chloromercuribenzoic acid (PCMB), pepstatin, or aprotinin, but after 30 min, bestatin was more effective. Intravenous injection of the tritiated peptides into rats showed short half-time disappearances; again, MIF-1 persisted in blood longer than Tyr-MIF-1. Thus, the results show the rapid metabolism of Tyr-MIF-1 in human and rat plasma, the slightly slower metabolism of MIF-1 in rat plasma, the predominant formation of Tyr-Pro rather than MIF-1 from Tyr-MIF-1, and the markedly delayed metabolism of MIF-1 in human plasma.


Asunto(s)
Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Hormona Inhibidora de la Liberación de MSH/metabolismo , Secuencia de Aminoácidos , Animales , Inhibidores Enzimáticos/farmacología , Humanos , Hormona Inhibidora de la Liberación de MSH/sangre , Hormona Inhibidora de la Liberación de MSH/farmacocinética , Masculino , Datos de Secuencia Molecular , Ratas , Temperatura , Factores de Tiempo , Tritio
8.
Ann N Y Acad Sci ; 897: 136-44, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10676442

RESUMEN

Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2, EM-1) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH2, EM-2) are peptides recently isolated from brain that show the highest affinity and selectivity for the mu (morphine) opiate receptor of all the known endogenous opioids. The endomorphins have potent analgesic and gastrointestinal effects. At the cellular level, they activate G-proteins (35S-GTP gamma-S binding) and inhibit calcium currents. Support for their role as endogenous ligands for the mu-opiate receptor includes their localization by radioimmunoassay and immunocytochemistry in central nervous system regions of high mu receptor density. Intense EM-2 immunoreactivity is present in the terminal regions of primary afferent neurons in the dorsal horn of the spinal cord and in the medulla near high densities of mu receptors. Chemical (capsaicin) and surgical (rhizotomy) disruption of nociceptive primary afferent neurons depletes the immunoreactivity, implicating the primary afferents as the source of EM-2. Thus, EM-2 is well-positioned to serve as an endogenous modulator of pain in its earliest stages of perception. In contrast to EM-2, which is more prevalent in the spinal cord and lower brainstem, EM-1 is more widely and densely distributed throughout the brain than EM-2. The distribution is consistent with a role for the peptides in the modulation of diverse functions, including autonomic, neuroendocrine, and reward functions as well as modulation of responses to pain and stress.


Asunto(s)
Bulbo Raquídeo/fisiología , Neuronas/fisiología , Oligopéptidos/fisiología , Receptores Opioides mu/fisiología , Médula Espinal/fisiología , Vías Aferentes/fisiología , Animales , Humanos , Receptores Opioides mu/agonistas
9.
Metabolism ; 49(11): 1444-8, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11092509

RESUMEN

Agouti-related protein (AgRP), expressed in both the periphery and the brain, can result in obesity. Its active C-terminal fragment, AgRP(83-132), was recently reported to increase feeding and antagonize alpha-melanocyte-stimulating hormone (alpha-MSH) and leptin. We used multiple-time regression analysis to show that the rate at which AgRP(83-132) crossed the blood-brain barrier (BBB) from the blood to the brain was very slow (Ki = 0.6 x 10(-4) mL/g x min). Entry was not self-inhibited by excess AgRP(83-132) after either intravenous (i.v.) injection or perfusion in blood-free medium, indicating the absence of a saturable transport system, and was not cross-inhibited by alpha-MSH or leptin. Not only did AgRP(83-132) cross much slower than the saturably entering leptin, but the entry was slower than almost all other non-saturably entering endogenous peptides or neurotrophins. Nevertheless, high-performance liquid chromatography (HPLC) showed that the small amount of AgRP(83-132) crossing the BBB did so in intact form, and capillary depletion showed that it entered the brain parenchyma rather than binding to capillary endothelial cells or adhering to vascular components. There was no rapid efflux system out of the brain that might have misleadingly appeared as slow entry for AgRP(83-132). Poor lipophilicity was shown by a low octanol/buffer partition coefficient. By size-exclusion chromatography, AgRP(83-132) appeared as a 17-kd substance in both blood and buffer. Since protein was absent from the buffer, the 17-kd peak probably represented a trimer of the 5.7-kd AgRP(83-132). Capillary electrophoresis confirmed that most of the AgRP(83-132) existed as a trimer, with much smaller amounts as a dimer and monomer. Thus, although intact AgRP(83-132) can cross the BBB from the blood to the brain, its nonsaturable rate of entry is very slow, probably influenced by aggregation.


Asunto(s)
Barrera Hematoencefálica , Fragmentos de Péptidos/farmacocinética , Proteína Relacionada con Agouti , Animales , Encéfalo/metabolismo , Cromatografía en Gel , Cromatografía Líquida de Alta Presión , Electroforesis Capilar , Semivida , Masculino , Ratones , Ratones Endogámicos ICR
10.
Peptides ; 15(6): 945-50, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7991457

RESUMEN

Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2), Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2), and MIF-1 (Pro-Leu-Gly-NH2) are biologically active peptides previously isolated from brain tissue. We now have used size exclusion chromatography and several consecutive rp-HPLC steps monitored by RIA to isolate a structurally related peptide from human brain cortex with the sequence Tyr-Pro-Lys-Gly-NH2 (Tyr-K-MIF-1). Determination of the sequence, electrospray mass spectrometry, and comparison of its chromatographic behavior with synthetic Tyr-K-MIF-1 confirmed the structure. Unlike Tyr-MIF-1 and Tyr-W-MIF-1, Tyr-K-MIF-1 does not bind to the mu opiate site; unlike MIF-1, Tyr-K-MIF-1 can bind to the Tyr-MIF-1 site. Of these peptides, only Tyr-K-MIF-1 binds to its own site in brain tissue prepared in Tris buffer. Thus, a new member of the Tyr-MIF-1 family of peptides, with a unique profile of binding, has been isolated from human brain cortex.


Asunto(s)
Lóbulo Frontal/química , Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Receptores de Hormona Reguladora de Hormona Hipofisaria/metabolismo , Secuencia de Aminoácidos , Humanos , Hormona Inhibidora de la Liberación de MSH/síntesis química , Hormona Inhibidora de la Liberación de MSH/aislamiento & purificación , Hormona Inhibidora de la Liberación de MSH/metabolismo , Espectrometría de Masas , Datos de Secuencia Molecular , Unión Proteica , Receptores Opioides/metabolismo , Análisis de Secuencia , Homología de Secuencia de Aminoácido , Membranas Sinápticas/metabolismo
11.
Peptides ; 15(8): 1567-9, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7700858

RESUMEN

Two cyclic analogues of the brain peptide Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2) were synthesized and tested for analgesic activity in the rat tail flick test after intracerebroventricular (ICV) injection. The analogues were about 200-fold more potent than the parent peptide. Analgesia was dose dependent, and at 1 microgram the two analogues, the mu-selective enkephalin analogue DAMGO (Tyr-D-Ala-Gly-N-Me-Phe-Gly-ol), and morphine, all produced analgesia lasting between 40 and 60 min. Analgesia of longer duration was evident at higher doses of the analogues and lasted more than 6 h after 100 micrograms, the highest dose tested. The results show that peptide analogues based on the structure of the endogenously occurring Tyr-W-MIF-1 can produce potent and long-lasting effects on nociception.


Asunto(s)
Analgésicos/farmacología , Ventrículos Cerebrales/fisiología , Encefalinas/farmacología , Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Morfina/farmacología , Péptidos Cíclicos/farmacología , Analgesia , Animales , Ventrículos Cerebrales/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Encefalina Ala(2)-MeFe(4)-Gli(5) , Encefalinas/administración & dosificación , Inyecciones Intraventriculares , Hormona Inhibidora de la Liberación de MSH/farmacología , Masculino , Morfina/administración & dosificación , Antagonistas de Narcóticos/farmacología , Dolor , Péptidos Cíclicos/administración & dosificación , Péptidos Cíclicos/síntesis química , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
12.
Peptides ; 18(10): 1635-9, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9437727

RESUMEN

Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2) and endomorphin-2 (Tyr-Pro-Phe-Phe-NH2) were previously isolated from bovine brain. Both peptides showed the greatest selectivity and affinity for the mu opiate receptor of any endogenous substance found to date and may serve as natural ligands for the mu-opiate receptor. We have purified them from the fronto-parietal cortex of human brain tissue by solid phase extraction and high performance liquid chromatography. Peptide content was followed by a specific and sensitive radioimmunoassay with an antibody that was generated against endomorphin-1. The isolated endomorphins showed full biological activity. The tetrapeptides were found in human brain in much higher amounts than in bovine frontal cortex.


Asunto(s)
Corteza Cerebral/química , Oligopéptidos/aislamiento & purificación , Secuencia de Aminoácidos , Analgésicos Opioides/aislamiento & purificación , Animales , Unión Competitiva , Bovinos , Cromatografía Líquida de Alta Presión , Encefalina Ala(2)-MeFe(4)-Gli(5) , Encefalinas/metabolismo , Humanos , Oligopéptidos/síntesis química , Oligopéptidos/química , Oligopéptidos/metabolismo , Radioinmunoensayo , Receptores Opioides mu/agonistas , Receptores Opioides mu/metabolismo
13.
Peptides ; 18(9): 1393-7, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9392842

RESUMEN

Endomorphin 1 and 2 are recently discovered endogenous ligands for the mu-opioid receptor. In the present study, responses to intravenous administration of endomorphin 1 and 2 were investigated in the systemic vascular bed of the rat. Endomorphin 1 and 2 induced dose-related decreases in systemic arterial pressure when injected in doses of 10-100 nmol/kg i.v.. The decreases in systemic arterial pressure in response to endomorphin 1 and 2 were associated with significant decreases in heart rate, cardiac output, and total peripheral resistance. The endogenous ligand for the ORL1 receptor, nociceptin/OFQ had similar effects on systemic arterial pressure, heart rate, cardiac output, and total peripheral resistance in the rat. Injections of isoproterenol (1 microgram/kg i.v.) and calcitonin gene-related peptide (CGRP; 0.3 nmol/kg i.v.), decreased systemic arterial pressure and total peripheral resistance. However these decreases in arterial pressure were associated with increases in heart rate and cardiac output. The results of the present study demonstrate that the endomorphin peptides have significant vasodilator activity in the systemic vascular bed of the rat and show that this response is associated with a decrease in heart rate and cardiac output.


Asunto(s)
Gasto Cardíaco/efectos de los fármacos , Oligopéptidos/farmacología , Receptores Opioides mu/agonistas , Resistencia Vascular/efectos de los fármacos , Animales , Péptido Relacionado con Gen de Calcitonina/farmacología , Cardiotónicos/farmacología , Femenino , Isoproterenol/farmacología , Ligandos , Masculino , Péptidos Opioides/farmacología , Ratas , Ratas Sprague-Dawley , Nociceptina
14.
Neuropeptides ; 24(3): 159-64, 1993 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8097302

RESUMEN

Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2) was recently isolated from human brain cortex. We have now isolated it from bovine hypothalami by solid phase extraction and several consecutive rpHPLC steps monitored by an RIA originally developed for the endogenous brain peptide Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2). Determination of the sequence of the purified material and comparison of its chromatographic behavior with synthetic Tyr-W-MIF-1 confirmed the structure. The synthetic peptide and the isolated material showed almost identical binding to mu opiate receptors.


Asunto(s)
Hipotálamo/química , Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Neuropéptidos/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Bovinos , Hormona Inhibidora de la Liberación de MSH/aislamiento & purificación , Hormona Inhibidora de la Liberación de MSH/metabolismo , Datos de Secuencia Molecular , Neuropéptidos/metabolismo , Receptores Opioides mu/metabolismo
15.
Neuropeptides ; 28(1): 65-71, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7746353

RESUMEN

Tyr-MIF-1-like immunoreactivity (Tyr-MIF-1-LI) was measured in the plasma of hypophysectomized rats. The concentrations were increased in every rat examined, regardless of sex or time after hypophysectomy, and ranged from 2.5 to 10 times greater than the concentrations in intact rats. The elevated concentrations were not decreased by replacement by thyroxine, estrogen and progesterone, or acute injection of corticosterone. Chronic administration of physiological doses of corticosterone, however, did reduce the concentrations to normal. High performance liquid chromatography of tritiated Tyr-MIF-1 incubated at 37 degrees C for 3 min in plasma obtained by hypophysectomized rats eliminated the possibility that reduced degradation of Tyr-MIF-1 explained the increased concentrations. Thus, the increase in Tyr-MIF-1-LI in the plasma of hypophysectomized rats is robust and reversible by chronic replacement of corticosterone.


Asunto(s)
Corticosterona/farmacología , Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Animales , Femenino , Hipofisectomía , Inmunohistoquímica , Hormona Inhibidora de la Liberación de MSH/sangre , Hormona Inhibidora de la Liberación de MSH/farmacología , Masculino , Hipófisis/fisiología , Ratas , Factores de Tiempo
16.
Neurosci Lett ; 155(2): 220-2, 1993 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-8104325

RESUMEN

A peptide recently isolated from human and bovine brain, Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2), was tested for its effects on nociception in the tail-flick test after intracerebroventricular injection in the rat. Tail-flick latencies were significantly increased with a rapid onset and remained significantly elevated for at least 50 min. Naloxone reversed the effect of the peptide, indicating opiate receptor involvement in the response. Met-enkephalin at the same dose produced only slight antinociception. Some animals showed 'barrel-rolling' behavior in addition to the analgesia; this behavior was unusually short-lived, not a prerequisite for the analgesia, and had no apparent persistent effects. The results show that, in addition to previously described opiate-like actions (binding to the mu-receptor and inhibition of electrically induced contractions of the guinea pig ileum), Tyr-W-MIF-1 is capable of inducing significant analgesia.


Asunto(s)
Analgésicos Opioides/farmacología , Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Secuencia de Aminoácidos , Analgésicos Opioides/administración & dosificación , Animales , Inyecciones Intraventriculares , Hormona Inhibidora de la Liberación de MSH/administración & dosificación , Hormona Inhibidora de la Liberación de MSH/antagonistas & inhibidores , Hormona Inhibidora de la Liberación de MSH/farmacología , Masculino , Datos de Secuencia Molecular , Actividad Motora/efectos de los fármacos , Naloxona/farmacología , Dolor/prevención & control , Ratas , Ratas Sprague-Dawley , Factores de Tiempo
17.
Neurosci Lett ; 215(1): 65-9, 1996 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-8880755

RESUMEN

Two endogenous brain peptides (Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2) and Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2)), a cyclized analog and two fragments of Tyr-W-MIF-1, and hemorphin (Tyr-Pro-Trp-Thr) were tested for binding to mu 1 and mu 2 opiate receptor. All these peptides bound to both mu 1 and mu 2 sites in assays optimized to discriminate these subtypes of the mu opiate receptor in membranes from bovine thalamus. The cyclized analog of Tyr-W-MIF-1, previously shown to have potency near that of Tyr-D-Ala-Gly-N-MePhe-Gly-ol (DAMGO) and morphine in producing analgesia after intracerebroventricular (i.c.v.) injection, bound to mu 1 and mu 2 sites with affinities similar to those of DAMGO. Tyr-W-MIF-1, previously shown to induce analgesia after i.c.v. injection but with much higher potency after intrathecal (i.t.) injection, also bound to both mu 1 and mu 2 sites with an affinity between that of morphiceptin and hemorphin. Although the highest ratios of Ki's for mu 2/mu 1 were shown by hemorphin, Tyr-W-MIF-1, and Tyr-W-MIF-1, none of the compounds were significantly different in selectivity. The results indicate that the relatively lower potency of Tyr-W-MIF-1 after i.c.v., compared with i.t. injection, is not due to a lack of binding to mu 1 sites. They suggest that it has relatively high efficacy at mu 2, but low efficacy at mu 1 sites, a possibility that might explain some of the novel properties of these peptides.


Asunto(s)
Unión Competitiva , Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Antagonistas de Narcóticos/farmacología , Péptidos/farmacología , Receptores Opioides mu/efectos de los fármacos , Tálamo/efectos de los fármacos , Animales , Bovinos , Relación Dosis-Respuesta a Droga , Hormona Inhibidora de la Liberación de MSH/farmacología
18.
Brain Res Bull ; 36(1): 109-11, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-7882043

RESUMEN

Tyr-MIF-1 previously was isolated from tissue obtained after death. A possible role of autolysis could not be excluded. We report the isolation of Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) in increased amounts from fresh human brain cortex. This confirms the natural existence of this brain peptide.


Asunto(s)
Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Corteza Cerebral/química , Cromatografía Líquida de Alta Presión , Humanos , Hormona Inhibidora de la Liberación de MSH/aislamiento & purificación , Radioinmunoensayo
19.
Life Sci ; 55(24): PL461-6, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7990646

RESUMEN

The relative binding to mu, delta, and kappa opiate receptors was characterized for the brain peptides Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2), Tyr-W-MIF-1 (Tyr-Pro-Trp-Gly-NH2), and two fragments of Tyr-W-MIF-1 (Tyr-Pro-Trp and Tyr-Pro-Trp-Gly) previously shown to have antagonist as well as agonist activity in the guinea pig ileum. Tyr-MIF-1 had relatively low affinity (Ki = 1 microM at the mu site) but high selectivity (400- and 700-fold greater affinity for mu over delta and mu over kappa binding). Tyr-W-MIF-1 (Ki = 71 nM at the mu site) showed higher affinity binding to all three sites than Tyr-MIF-1 while retaining 200-fold selectivity for mu over delta and kappa receptors. The affinity of the fragments of Tyr-W-MIF-1 was lower for mu but higher for delta receptors. We also tested two cyclized analogs of Tyr-W-MIF-1 that were about 200-fold more active than the parent compound in producing analgesia. These analogs showed higher affinity binding to all three opiate receptors. One of the analogs showed binding affinity to mu sites (Ki = 1.3 nM) that was within 3-fold of that of the potent analog of enkephalin, DAMGO. Thus, brain peptides with an N-terminal Tyr-Pro, rather than the Tyr-Gly-Gly-Phe sequence typical of other endogenous opiates, can provide high selectivity for mu opiate receptors. Analogs based on one of them, Tyr-Pro-Trp-Gly-NH2, show high affinity as well as potent analgesic activity.


Asunto(s)
Hormona Inhibidora de la Liberación de MSH/análogos & derivados , Fragmentos de Péptidos/metabolismo , Péptidos Cíclicos/metabolismo , Receptores Opioides/metabolismo , Secuencia de Aminoácidos , Animales , Encéfalo , Cerebelo , Endorfinas/metabolismo , Encefalina Ala(2)-MeFe(4)-Gli(5) , Encefalinas/metabolismo , Cobayas , Hormona Inhibidora de la Liberación de MSH/metabolismo , Datos de Secuencia Molecular , Ratas , Receptores Opioides delta/metabolismo , Receptores Opioides kappa/metabolismo , Receptores Opioides mu/metabolismo , Relación Estructura-Actividad , Membranas Sinápticas/metabolismo
20.
Life Sci ; 62(13): PL175-9, 1998.
Artículo en Inglés | MEDLINE | ID: mdl-9519803

RESUMEN

The endogenous opioid peptides, endomorphin 1 and 2, are newly isolated, potent, and selective mu-opioid receptor agonists. In the present study, responses to endomorphin 1 and 2 were investigated in the systemic vascular bed of the rat. Endomorphin 1 and 2 induced dose-related decreases in systemic arterial pressure when injected in doses of 1-30 nmol/kg i.v. In terms of relative vasodepressor activity, endomorphin 1 and 2 were approximately equipotent with each other and with the ORL1 ligand, nociceptin (orphanin FQ), and were about 10-fold more potent than met-enkephalin in decreasing systemic arterial pressure. Vasodepressor responses to endomorphin 1 and 2 and met-enkephalin, but not to nociceptin, were inhibited by the opioid receptor antagonist, naloxone. These results demonstrate that endomorphin 1 and 2 produce significant naloxone-sensitive decreases in systemic arterial pressure.


Asunto(s)
Analgésicos Opioides/farmacología , Presión Sanguínea/efectos de los fármacos , Oligopéptidos/farmacología , Receptores Opioides mu/agonistas , Vasoconstrictores/farmacología , Analgésicos Opioides/farmacocinética , Animales , Encefalina Metionina/farmacología , Femenino , Masculino , Oligopéptidos/farmacocinética , Péptidos Opioides/farmacología , Ratas , Ratas Sprague-Dawley , Vasoconstrictores/farmacocinética , Nociceptina
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