RESUMEN
The concentrations of gamma 3-melanotropin-, alpha-melanotropin-, corticotropin-, gamma-lipotropin- and beta-endorphin-immunoreactivities were determined simultaneously, before and after gel exclusion chromatography, in whole hypothalamic extracts of normal subjects and Parkinson patients. All five immunoreactivities were present and were all significantly correlated to each other. Shorter peptides (alpha-melanotropin, gamma 3-melanotropin, beta-endorphin and a lipotropin37-58-like peptide) were the dominant products. Whereas the dopamine content was significantly reduced in Parkinson patients, there was no significant difference for any peptide between normal subjects and Parkinson patients, either in tissue concentrations or in chromatographic patterns.
Asunto(s)
Hipotálamo/análisis , Enfermedad de Parkinson/metabolismo , Proopiomelanocortina/análisis , Hormona Adrenocorticotrópica/análisis , Anciano , Cromatografía en Gel , Endorfinas/análisis , Femenino , Humanos , Masculino , Hormonas Estimuladoras de los Melanocitos/análisis , Radioinmunoensayo , betaendorfina , beta-Lipotropina/análisisRESUMEN
We assayed the content of neurotransmitters (or their synthesizing enzymes) and neuropeptides in the hypothalamus of control and parkinsonian brains post mortem. Only dopamine concentrations were lower than normal in Parkinson's disease, suggesting that deficiency in hypothalamic dopamine transmission may play a role in the autonomic and endocrine abnormalities of this disorder.
Asunto(s)
Hipotálamo/metabolismo , Neurotransmisores/metabolismo , Enfermedad de Parkinson/metabolismo , Anciano , Dopamina/metabolismo , Humanos , Proteínas del Tejido Nervioso/metabolismo , Norepinefrina/metabolismoRESUMEN
Tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) activities, dopamine (DA), noradrenaline (NA), adrenaline (A), met 5-enkephalin (Met-Enk), leu5-enkephalin (Leu-Enk), dynorphin (Dyn) and beta-endorphin (beta-end) were measured simultaneously in ten human pheochromocytomas = 1 - TH activity was highly variable, from 22 to 2220 U/g tissue. 2 - DBH activity, in contrast, was rather constant, from 96 to 582 U/g. 3 - Catecholamines (A and NA) concentrations showed only small variations. 4 - The four opioid peptides were detected in all cases and exhibited a wide range of tissue concentrations (Enk much greater than Dyn greater than beta-end). 5 - Met-Enk and Leu-Enk concentrations were highly correlated; no correlation was observed with the other opioid peptides. 6 - A very strong correlation was observed between enkephalins concentrations and both catecholamines concentrations and DBH activities. These results are discussed in term of the significance of the co-localization of these various biologically active substances, principally with regard to the possible regulation of catecholamine synthesis by opioid peptides and conversely.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/fisiopatología , Catecolaminas/biosíntesis , Endorfinas/metabolismo , Feocromocitoma/fisiopatología , Dopamina/metabolismo , Dopamina beta-Hidroxilasa/metabolismo , Epinefrina/metabolismo , Humanos , Norepinefrina/metabolismo , Tirosina 3-Monooxigenasa/metabolismoRESUMEN
Peptides related to the NH2-terminus of proopiocortin in man were studied with three different RIAs directed toward gamma 3MSH, human 16K, and mouse 16K. The culture medium derived from a human corticotropic adenoma (SCH medium), which had previously been used as a human reference standard, generated competitive binding curves parallel to that of purified human 16K in all three RIA systems. Gel exclusion chromatography performed with pituitary-derived materials (adenoma extract and medium, and plasma from patients with Nelson's syndrome) showed that the overall immunoreactive gamma 3MSH eluted as one major peak at the position of human 16K. Its molecular weight estimated under denaturing conditions was 11,000. Gel exclusion chromatography performed with nonpituitary-derived materials (tumor extract and plasma from patient with the ectopic ACTH syndrome) showed that a major peak eluted at the position of human 16K, and a smaller molecular weight peptide eluted in a position intermediary between that of human 16K and synthetic gamma 3MSH. These data show that immunoreactive gamma 3MSH is indeed identical to human 16K in pituitary-derived materials. A different processing of the proopiocortin molecule is likely to occur in nonpituitary tumors and will result in the release of a smaller molecular weight peptide. The exact nature of this peptide is not known. It is speculated that it may serve as a nonpituitary tumor marker.
Asunto(s)
Fragmentos de Péptidos/aislamiento & purificación , Hormonas Hipofisarias/aislamiento & purificación , Proopiomelanocortina , Adenoma/metabolismo , Animales , Cromatografía en Gel , Cobayas , Humanos , Hormonas Estimuladoras de los Melanocitos/aislamiento & purificación , Ratones , Peso Molecular , Síndrome de Nelson/metabolismo , Neoplasias Hipofisarias/metabolismo , Precursores de Proteínas/aislamiento & purificación , RadioinmunoensayoRESUMEN
Tissue concentrations of immunoreactive lipotrophin, beta-endorphin, and met-enkephalin were determined in 10 phaeochromocytomas, 3 of which were responsible for the ectopic ACTH syndrome. Lipotrophin and beta-endorphin immunoreactivities could be detected in all cases, whether or not Cushing's syndrome was present, and their tissue concentrations were significantly correlated (r = 0.95, P less than 0.001). Chromatographic studies showed that gamma-lipotrophin and beta-endorphin were the main peptides in the tumours. Met-enkephalin immunoreactivity was also found in all tumours examined, at much higher concentration and showing no correlation with either lipotrophin or beta-endorphin immunoreactivity. Although beta-endorphin and met-enkephalin are thought to originate from different precursor molecules, these data show that the two opioid peptides may be secreted by the same tumour. The evidence for excess secretion of opioid peptides and their pathological significance in phaeochromocytomas remain to be established.
Asunto(s)
Neoplasias de las Glándulas Suprarrenales/análisis , Endorfinas/análisis , Encefalina Metionina/análisis , Feocromocitoma/análisis , beta-Lipotropina/análisis , Adolescente , Hormona Adrenocorticotrópica/análisis , Adulto , Anciano , Cromatografía en Gel , Femenino , Humanos , Masculino , Persona de Mediana Edad , betaendorfinaRESUMEN
Several anti-LH RH antisera have been raised in Rabbits given as immunogen the synthetic decapeptide linked to bovine serum albumin by carbodiimide or bis-diazotized benzidine. Antibodies obtained with CDI as a coupling agent showed the highest titers and affinities enabling measurement of LH RH levels lower than 1 pg/tube. The specificity of the antisera, particularly toward 13 fragments of the molecule, were similar irrespective of the immunogen used.
Asunto(s)
Hormona Liberadora de Gonadotropina/inmunología , Animales , Formación de Anticuerpos , Reacciones Cruzadas , Haptenos , Sueros Inmunes , Fragmentos de Péptidos , Conejos , RadioinmunoensayoRESUMEN
The antigenic properties of human prolactin (HPr) were studied using various methods of radio-immuno assay. The homologous system, the difficulty of which resides in the preparation of the tracer, easily permits measurement of physiological levels. In this systems, blood prolactin in the monkey, has an antigenicity comparable with that of human prolactin, whereas growth hormone and human chorionic somatotropin have feeble or nil antigenic relationship with HPr. Human, sheep and pig prolactins have variable antigenic cross-reactions depending on the immune serum used. These antigenic cross reactions may be applied to the isolation of amniotic prolactin Human blood prolactin has several components of different molecular weight, but antigenicity comparable with that of pituitary HPr.