No hipotálamo, centro regulador de uma variedade de comportamentos inclusive o reprodutivo, são produzidos diversos peptídeos moduladores, dentre eles o hormônio concentrador de melanina [MCH]. Já foi observada presença do MCH também em tecidos periféricos, incluindo os testículos. Por isso buscamos sua presença no ovário de ratas nas fases do ciclo estral, gestantes e lactantes. Para a determinação da presença do peptídeo foram utilizados os métodos de imuno-histoquímica e western blotting, para a detecção do RNAm, a hibridização in situ e RT-PCR, e ensaio imunoenzimático para determinação de níveis séricos hormonais de progesterona, prolactina e MCH. Nossos experimentos indicam a presença do RNAm do ppMCH no ovário, bem como do peptídeo em todas as fases do ciclo reprodutivo, no corpo lúteo e na medula ovariana, resultado quantificado pela técnica de western blotting. Além do mais, observamos que os níveis séricos de MCH são constantes nas fases analisadas e que a contribuição do ovário nesses níveis é significativa. / In the hypothalamus, the regulatory center of a variety of behaviors, including reproductive behavior, several peptides modulating these functions are produced, among them the melanin-concentrating hormone [MCH]. In addition to the brain tissue, its presence in several peripheral tissues, including the testis, has been observed. Therefore, we used rats to investigate the presence of MCH in the estrous cycle phase, during gestation and lactation periods. In order to determine the presence of the peptide, immunohistochemistry and western blotting methods were used. To detect the preproMCH RNAm, we used in situ hybridization and RT-PCR, and immunoenzymatic assay to determine serum levels of progesterone, prolactin and MCH. Our findings demonstrated the presence of ppMCH mRNA in ovary, as well as the peptide, and it was localized in the corpus luteum and ovarian marrow. Furthermore, we observed that serum MCH levels are constant in the analyzed phases and that the contribution of the ovary at these levels is significant.

The purpose of this research was to determine whether genetic variation existed within <i>Bos taurus</i> Pro-melanin-concentrating hormone (PMCH), and whether this variation would affect carcass traits. PMCH had previously been shown to affect appetite and metabolism in rodent species, thus it was desirable to determine whether the gene had a similar effect in cattle, which could be interpreted based on carcass measurements of weight gain and fat production. Cattle PMCH was sequenced and an adenosine-to-thymine (A>T) single nucleotide polymorphism (SNP) was detected 134 bp upstream of the translational start site. The SNP alleles were determined to significantly affect carcass traits including average fat and grade fat in two populations of cattle, and shear force measurements in one population. The adenosine homozygotes were found to have the highest fat levels and the thymine homozygotes the least, while the heterozygous animals had intermediate fat levels. Shear force values in the one available population indicated that cuts of meat from the adenosine homozygotes were most tender, while cuts from the thymine homozygotes were least tender. <p>The SNP was also found to significantly affect tenderness and palatability of meat, as evaluated by a consumer taste panel. The meat from adenosine homozygotes was found to be most tender and palatable. These results could not be validated as this data was unavailable in additional populations. <p>The location of the SNP suggested that it may affect PMCH transcription rates. In silico examination of the different alleles indicated that the thymine allele introduces a novel transcriptional repressor binding site for Adenovirus E4 Promoter Binding protein (E4BP4). Thus, it is believed that the SNP may affect transcriptional levels of the gene by reducing transcription rates in the presence of the thymine allele. <p>Cattle producers are expected to produce cattle with consistent amounts of lean meat and fat. Genetic testing of alleles found to affect fat production and meat tenderness traits are currently available to producers. A DNA test to select breeding stock based on PMCH alleles could be used in conjunction with other tests currently available to further improve carcass quality by selecting for animals with beneficial alleles at numerous genetic loci. Additionally, producers could make use of these findings to genetically sort cattle upon feedlot entry, maximizing the consistency of the finished beef product.

The purpose of this research was to determine whether genetic variation existed within <i>Bos taurus</i> Pro-melanin-concentrating hormone (PMCH), and whether this variation would affect carcass traits. PMCH had previously been shown to affect appetite and metabolism in rodent species, thus it was desirable to determine whether the gene had a similar effect in cattle, which could be interpreted based on carcass measurements of weight gain and fat production. Cattle PMCH was sequenced and an adenosine-to-thymine (A>T) single nucleotide polymorphism (SNP) was detected 134 bp upstream of the translational start site. The SNP alleles were determined to significantly affect carcass traits including average fat and grade fat in two populations of cattle, and shear force measurements in one population. The adenosine homozygotes were found to have the highest fat levels and the thymine homozygotes the least, while the heterozygous animals had intermediate fat levels. Shear force values in the one available population indicated that cuts of meat from the adenosine homozygotes were most tender, while cuts from the thymine homozygotes were least tender. <p>The SNP was also found to significantly affect tenderness and palatability of meat, as evaluated by a consumer taste panel. The meat from adenosine homozygotes was found to be most tender and palatable. These results could not be validated as this data was unavailable in additional populations. <p>The location of the SNP suggested that it may affect PMCH transcription rates. In silico examination of the different alleles indicated that the thymine allele introduces a novel transcriptional repressor binding site for Adenovirus E4 Promoter Binding protein (E4BP4). Thus, it is believed that the SNP may affect transcriptional levels of the gene by reducing transcription rates in the presence of the thymine allele. <p>Cattle producers are expected to produce cattle with consistent amounts of lean meat and fat. Genetic testing of alleles found to affect fat production and meat tenderness traits are currently available to producers. A DNA test to select breeding stock based on PMCH alleles could be used in conjunction with other tests currently available to further improve carcass quality by selecting for animals with beneficial alleles at numerous genetic loci. Additionally, producers could make use of these findings to genetically sort cattle upon feedlot entry, maximizing the consistency of the finished beef product.

No description available.

Sepiolite is a clay mineral, a complex magnesium silicate, a typical formula for which is (OH2)4(OH)4Mg8Si12O30•8H2O. It is formed by blocks and cavities (tunnels) growing in the direction of the fibres. The tunnels, 3.7 x 10.6 Å in cross-section, are responsible for the high specific surface area and sorptive properties of sepiolite. The co-intercalation of 3-methyl cyclohex-2-en-1-one (MCH), the Douglas-Fir beetle anti-aggregation pheromone, with methanol, ethanol, acetone, or benzene into sepiolite tunnels was studied. The resulting nanohybrid materials were characterized by means of various techniques, such as multinuclear solid-state NMR spectroscopy, porosity studies and Thermal Gravimetric Analysis (TGA). This was done in the hope of obtaining slow and controlled release of MCH from the sepiolite tunnels. It was demonstrated by 13C MAS NMR (carbon-13 magic angle spinning nuclear magnetic resonance) that at room temperature there are two different MCH molecules: one MCH inside the tunnels and the other one outside the tunnels of the sepiolite. Heating nanohybrid materials at 60˚C for 20 hours removes the external MCH molecules from the sepiolite. 13C MAS NMR showed that by further heating nanohybrid materials at 120˚C for 20 hours, methanol, ethanol, or acetone peaks were greatly reduced; however, the benzene peak was not reduced. To better understand how benzene acts inside sepiolite, intercalation of d6-benzene, and co-intercalations of d6-benzene with MCH and d6-benzene with pyridine into sepiolite tunnels were carried out, and these samples were studied by the same techniques. Another technique was used in order to see whether the slow and controlled release of MCH from the sepiolite tunnels could be obtained: sepiolite-MCH nanohybrids were treated with 20 ml of 0.5 M HCl solution. It was found that when 1 gram of MCH-sepiolite sample was acid treated at room temperature, about 35% of intercalated MCH was removed from the sepiolite. The role of sepiolite clay was also studied in Maya-Blue representative structure sepiolite-indigo adduct. It is known that upon heating the sepiolite and indigo mixture, the stability that is present in Maya-Blue is achieved. It is still a mystery, however, how exactly indigo and sepiolite interact with each other.

Sepiolite is a clay mineral, a complex magnesium silicate, a typical formula for which is (OH2)4(OH)4Mg8Si12O30•8H2O. It is formed by blocks and cavities (tunnels) growing in the direction of the fibres. The tunnels, 3.7 x 10.6 Å in cross-section, are responsible for the high specific surface area and sorptive properties of sepiolite. The co-intercalation of 3-methyl cyclohex-2-en-1-one (MCH), the Douglas-Fir beetle anti-aggregation pheromone, with methanol, ethanol, acetone, or benzene into sepiolite tunnels was studied. The resulting nanohybrid materials were characterized by means of various techniques, such as multinuclear solid-state NMR spectroscopy, porosity studies and Thermal Gravimetric Analysis (TGA). This was done in the hope of obtaining slow and controlled release of MCH from the sepiolite tunnels. It was demonstrated by 13C MAS NMR (carbon-13 magic angle spinning nuclear magnetic resonance) that at room temperature there are two different MCH molecules: one MCH inside the tunnels and the other one outside the tunnels of the sepiolite. Heating nanohybrid materials at 60˚C for 20 hours removes the external MCH molecules from the sepiolite. 13C MAS NMR showed that by further heating nanohybrid materials at 120˚C for 20 hours, methanol, ethanol, or acetone peaks were greatly reduced; however, the benzene peak was not reduced. To better understand how benzene acts inside sepiolite, intercalation of d6-benzene, and co-intercalations of d6-benzene with MCH and d6-benzene with pyridine into sepiolite tunnels were carried out, and these samples were studied by the same techniques. Another technique was used in order to see whether the slow and controlled release of MCH from the sepiolite tunnels could be obtained: sepiolite-MCH nanohybrids were treated with 20 ml of 0.5 M HCl solution. It was found that when 1 gram of MCH-sepiolite sample was acid treated at room temperature, about 35% of intercalated MCH was removed from the sepiolite. The role of sepiolite clay was also studied in Maya-Blue representative structure sepiolite-indigo adduct. It is known that upon heating the sepiolite and indigo mixture, the stability that is present in Maya-Blue is achieved. It is still a mystery, however, how exactly indigo and sepiolite interact with each other.

Sepiolite is a clay mineral, a complex magnesium silicate, a typical formula for which is (OH2)4(OH)4Mg8Si12O30•8H2O. It is formed by blocks and cavities (tunnels) growing in the direction of the fibres. The tunnels, 3.7 x 10.6 Å in cross-section, are responsible for the high specific surface area and sorptive properties of sepiolite. The co-intercalation of 3-methyl cyclohex-2-en-1-one (MCH), the Douglas-Fir beetle anti-aggregation pheromone, with methanol, ethanol, acetone, or benzene into sepiolite tunnels was studied. The resulting nanohybrid materials were characterized by means of various techniques, such as multinuclear solid-state NMR spectroscopy, porosity studies and Thermal Gravimetric Analysis (TGA). This was done in the hope of obtaining slow and controlled release of MCH from the sepiolite tunnels. It was demonstrated by 13C MAS NMR (carbon-13 magic angle spinning nuclear magnetic resonance) that at room temperature there are two different MCH molecules: one MCH inside the tunnels and the other one outside the tunnels of the sepiolite. Heating nanohybrid materials at 60˚C for 20 hours removes the external MCH molecules from the sepiolite. 13C MAS NMR showed that by further heating nanohybrid materials at 120˚C for 20 hours, methanol, ethanol, or acetone peaks were greatly reduced; however, the benzene peak was not reduced. To better understand how benzene acts inside sepiolite, intercalation of d6-benzene, and co-intercalations of d6-benzene with MCH and d6-benzene with pyridine into sepiolite tunnels were carried out, and these samples were studied by the same techniques. Another technique was used in order to see whether the slow and controlled release of MCH from the sepiolite tunnels could be obtained: sepiolite-MCH nanohybrids were treated with 20 ml of 0.5 M HCl solution. It was found that when 1 gram of MCH-sepiolite sample was acid treated at room temperature, about 35% of intercalated MCH was removed from the sepiolite. The role of sepiolite clay was also studied in Maya-Blue representative structure sepiolite-indigo adduct. It is known that upon heating the sepiolite and indigo mixture, the stability that is present in Maya-Blue is achieved. It is still a mystery, however, how exactly indigo and sepiolite interact with each other.

Sepiolite is a clay mineral, a complex magnesium silicate, a typical formula for which is (OH2)4(OH)4Mg8Si12O30•8H2O. It is formed by blocks and cavities (tunnels) growing in the direction of the fibres. The tunnels, 3.7 x 10.6 Å in cross-section, are responsible for the high specific surface area and sorptive properties of sepiolite. The co-intercalation of 3-methyl cyclohex-2-en-1-one (MCH), the Douglas-Fir beetle anti-aggregation pheromone, with methanol, ethanol, acetone, or benzene into sepiolite tunnels was studied. The resulting nanohybrid materials were characterized by means of various techniques, such as multinuclear solid-state NMR spectroscopy, porosity studies and Thermal Gravimetric Analysis (TGA). This was done in the hope of obtaining slow and controlled release of MCH from the sepiolite tunnels. It was demonstrated by 13C MAS NMR (carbon-13 magic angle spinning nuclear magnetic resonance) that at room temperature there are two different MCH molecules: one MCH inside the tunnels and the other one outside the tunnels of the sepiolite. Heating nanohybrid materials at 60˚C for 20 hours removes the external MCH molecules from the sepiolite. 13C MAS NMR showed that by further heating nanohybrid materials at 120˚C for 20 hours, methanol, ethanol, or acetone peaks were greatly reduced; however, the benzene peak was not reduced. To better understand how benzene acts inside sepiolite, intercalation of d6-benzene, and co-intercalations of d6-benzene with MCH and d6-benzene with pyridine into sepiolite tunnels were carried out, and these samples were studied by the same techniques. Another technique was used in order to see whether the slow and controlled release of MCH from the sepiolite tunnels could be obtained: sepiolite-MCH nanohybrids were treated with 20 ml of 0.5 M HCl solution. It was found that when 1 gram of MCH-sepiolite sample was acid treated at room temperature, about 35% of intercalated MCH was removed from the sepiolite. The role of sepiolite clay was also studied in Maya-Blue representative structure sepiolite-indigo adduct. It is known that upon heating the sepiolite and indigo mixture, the stability that is present in Maya-Blue is achieved. It is still a mystery, however, how exactly indigo and sepiolite interact with each other.

No / In this study, we have demonstrated the presence of melanin-concentrating hormone (MCH) and melanin-concentrating hormone receptor (MCHR1) transcripts in human skin. Sequence analysis confirmed that the transcripts of both genes were identical to those previously found in human brain. In culture, endothelial cells showed pro-MCH expression whereas no signal was found in keratinocytes, melanocytes, and fibroblasts. MCHR1 expression was restricted to melanocytes and melanoma cells. Stimulation of cultured human melanocytes with MCH reduced the ¿-MSH-induced increase in cAMP production. Furthermore, the melanogenic actions of ¿-MSH were inhibited by MCH. We propose that the MCH/MCHR1 signalling system is present in human skin and may have a role with the melanocortins in regulating the melanocyte.

L’objectif de notre étude est d’améliorer la connaissance des réseaux neuronaux responsables de la régulation du sommeil paradoxal (SP). Dans ce but, nous avons combiné des techniques de polysomnographie, de neuroanatomie fonctionnelle, de pharmacologie et de traçage de voies nerveuses. Nous avons ainsi mis en évidence une population de neurones GABAergiques à la jonction entre la substance grise périaqueductale ventrolatérale et la partie dorsale du noyau profond du mésencéphale (vlPAG/dDpMe), capable de bloquer l’entrée en SP. Nous avons également démontré l’existence de nombreuses populations de neurones GABAergiques pontiques activés au cours du SP. De plus, nos travaux ont révélé la présence de nombreux neurones GABAergiques, dont les neurones à MCH, actifs en SP dans plusieurs régions hypothalamiques. Enfin, nous avons établi une cartographie des neurones à MCH et à Hcrt envoyant des projections sur les neurones histaminergiques du noyau tubéromammillaire ventral (VTM), promoteurs de l’éveil. L’ensemble de notre travail de thèse a permis d’affiner le modèle des réseaux neuronaux impliqués dans la régulation du SP, particulièrement en confirmant le rôle du GABA dans ces mécanismes de régulation / The aim of our study is to improve the knowledge of the neural networks responsible for paradoxical sleep (PS) regulation. To this end, we combined polysomnographic recordings, functional neuroanatomy, pharmacology and tract-tracing of nervous pathways. We thus highlighted a population of GABAergic neurons at the junction between the ventroleral periaqueductal gray and the dorsal part of the deep mesencephalic nucleus (vlPAG/dDpMe), able to gate PS genesis. We also showed the existence in the pons of several GABAergic neurons populations activated during PS. Moreover, our work revealed the presence of a large number of GABAergic neurons including the MCH neurons, activated in PS in several hypothalamic areas. Finally, we mapped the MCH, Hcrt neurons that send projections to the wake-promoting histaminergic neurons of the ventral tuberomammillary nucleus (VTM). Our thesis work made it possible to refine the model of neural networks involved in PS regulation, particularly by confirming the role of GABA in these mechanisms of regulation.