RESUMO
Fish freshness consists of complex endogenous and exogenous processes; therefore, the use of a few parameters to unravel illicit practices could be insufficient. Moreover, the development of strategies for the identification of such practices based on additives known to prevent and/or delay fish spoilage is still limited. The paper deals with the identification of the effect played by a Cafodos solution on the conservation state of sea bass at both short-term (3 h) and long-term (24 h). Controls and treated samples were characterized by a multi-omic approach involving proteomics, lipidomics, metabolomics, and metagenomics. Different parts of the fish samples were studied (muscle, skin, eye, and gills) and sampled through a non-invasive procedure based on EVA strips functionalized by ionic exchange resins. Data fusion methods were then applied to build models able to discriminate between controls and treated samples and identify the possible markers of the applied treatment. The approach was effective in the identification of the effect played by Cafodos that proved to be different in the short- and long-term and complex, involving proteins, lipids, and small molecules to a different extent.
Assuntos
Bass , Animais , MultiômicaRESUMO
BACKGROUND: The impact of the absence of gravity on cancer cells is of great interest, especially today that space is more accessible than ever. Despite advances, few and contradictory data are available mainly due to different setup, experimental design and time point analyzed. METHODS: Exploiting a Random Positioning Machine, we dissected the effects of long-term exposure to simulated microgravity (SMG) on pancreatic cancer cells performing proteomic, lipidomic and transcriptomic analysis at 1, 7 and 9 days. RESULTS: Our results indicated that SMG affects cellular morphology through a time-dependent activation of Actin-based motility via Rho and Cdc42 pathways leading to actin rearrangement, formation of 3D spheroids and enhancement of epithelial-to-mesenchymal transition. Bioinformatic analysis reveals that SMG may activates ERK5/NF-κB/IL-8 axis that triggers the expansion of cancer stem cells with an increased migratory capability. These cells, to remediate energy stress and apoptosis activation, undergo a metabolic reprogramming orchestrated by HIF-1α and PI3K/Akt pathways that upregulate glycolysis and impair ß-oxidation, suggesting a de novo synthesis of triglycerides for the membrane lipid bilayer formation. CONCLUSIONS: SMG revolutionizes tumor cell behavior and metabolism leading to the acquisition of an aggressive and metastatic stem cell-like phenotype. These results dissect the time-dependent cellular alterations induced by SMG and pave the base for altered gravity conditions as new anti-cancer technology.
Assuntos
Neoplasias Pancreáticas , Ausência de Peso , Actinas , Humanos , Lipidômica , Neoplasias Pancreáticas/genética , Fosfatidilinositol 3-Quinases , Proteômica , Transcriptoma , Simulação de Ausência de Peso/métodosRESUMO
Among vertebrates, the physiologically uremic Chondrichthyes are the only class which are not presenting the ciliated olfactory receptor neurons in the olfactory neuroepithelium. The only sequenced genome for this class revealed only three olfactory receptor genes and the immunohistochemical detection of G protein alpha subunit typically coupled to the olfactory receptors (Gα(olf)) failed in different species. Chronic renal disease can represent a cause of olfactory impairment in human. In this context, our present study focused on investigating potential effects of high urea concentration on the olfactory epithelium of vertebrates. Larvae of the teleost fish Danio rerio were exposed to urea in order to assess the effects on the olfactory signal transduction; in particular on both the olfactory receptors and the Gα(olf). The endocytosis of neutral red dye in the olfactory mucosa was detected in control and urea-exposed larvae. The amount of neutral red dye uptake was used as a marker of binding and internalization of the Gα(olf). The neutral red dye endocytosis was not affected by urea exposure, hence suggesting that the presence of the Gα(olf) and their binding to the odorants are not affected by urea treatment, either. The presence and distribution of Gα(olf) were investigated in the olfactory epithelium of control and urea-exposed larvae, using a commercial antibody. The immunoreactivity was increased after urea treatment, suggesting an effect of urea on the expression or degradation of this G protein alpha subunit.
Assuntos
Olfato/fisiologia , Ureia/farmacologia , Peixe-Zebra/fisiologia , Sequência de Aminoácidos , Animais , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/fisiologia , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Larva/efeitos dos fármacos , Larva/fisiologia , Vermelho Neutro , Transdução de Sinais/efeitos dos fármacos , Olfato/efeitos dos fármacos , Peixe-Zebra/embriologiaRESUMO
An open-label follow-up study of low-to-intermediate dose testosterone replacement therapy (TRT) was conducted in 64 overweight patients (aged 65-75 years) with late onset hypogonadism (LOH) and increased fasting plasma glucose (FPG). Patients were subdivided into four treatment groups: oral testosterone (T) (T undecanoate, 80 mg/d), transmucosal T (60 mg/d), transdermal T (30 mg/d) or no treatment (control), and evaluated at 0 and 6 months. FPG, hemoglobin (Hb), prostate-specific antigen (PSA) and total T were measured and the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) index was calculated. Body mass index (BMI), waist circumference, fitness level (6-min walking test), Aging Males' Symptoms (AMS) scale, handgrip strength and energy expenditure with physical activity (Minnesota questionnaire for Leisure Time Physical Activity (LTPA)) were evaluated and a "frailty score" (based on: grip strength, gait speed and LTPA) was calculated. T levels increased in all treatment groups; the oral T group had values still in the hypogonadal range (5.9 ± 1.1 nmol/L). PSA and Hb concentrations did not change in any group. BMI, waist circumference, FPG and HOMA-IR improved in all T-treated groups after 6 months, with a greater effect seen with transmucosal and transdermal T compared with oral T. This study indicates that low-to-intermediate dose TRT may be safely utilized in LOH patients to ameliorate somatic and psychological frailty symptoms in association with improved anthropometric and glycometabolic parameters in aging, overweight men with LOH and impaired fasting glucose.
Assuntos
Terapia de Reposição Hormonal/métodos , Hipogonadismo/tratamento farmacológico , Atividade Motora/efeitos dos fármacos , Testosterona/administração & dosagem , Administração Cutânea , Administração Oral , Idoso , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Glicemia/análise , Estudos de Coortes , Relação Dose-Resposta a Droga , Esquema de Medicação , Humanos , Hiperglicemia/diagnóstico , Hiperglicemia/tratamento farmacológico , Hipogonadismo/diagnóstico , Masculino , Atividade Motora/fisiologia , Força Muscular/efeitos dos fármacos , Força Muscular/fisiologia , Estudos Prospectivos , Antígeno Prostático Específico/sangue , Qualidade de Vida , Medição de Risco , Resultado do TratamentoRESUMO
In the age of space exploration, the effect of hypergravity on human physiology is a relatively neglected topic. However, astronauts have several experiences of hypergravity during their missions. The main disturbance of altered gravity can be imputed to cell cytoskeleton alteration and physiologic homeostasis of the body. Testis has proved to be a particularly sensible organ, subject to environmental alteration and physiological disturbance. This makes testis an organ eligible for investigating the alteration following exposure to altered gravity. In our study, mice were exposed to hypergravity (3g for 14 days) in the Large Diameter Centrifuge machine (ESA, Netherland). We have observed a morphological alteration of the regular architecture of the seminiferous tubules of testis as well as an altered expression of factors involved in the junctional complexes of Sertoli cells, responsible for ensuring the morpho-functional integrity of the organ. The expression of key receptors in physiological performance, such as Androgen Receptors and Interstitial Cells Stimulating Hormone receptors, was found lower expressed. All these findings indicate the occurrence of altered physiological organ performance such as the reduction of the spermatozoa number and altered endocrine parameters following hypergravity exposure.
Assuntos
Gravidade Alterada , Hipergravidade , Masculino , Adulto , Camundongos , Animais , Humanos , Hipergravidade/efeitos adversos , Testículo , Centrifugação , Gravitação , MamíferosRESUMO
BACKGROUND: Boswellia serrata gum resin has attracted pharmacological interest as an alternative antinflammatory. PURPOSE: We studied the application of an ethanolic extract of the resin and its main active 3-O-acetyl-11-keto-ß-boswellic acid (AKBA) against inflammatory degeneration of skin extracellular matrix. STUDY DESIGN: We compared the effects of the extract and AKBA on the activity of MMP-2 and MMP-9 (72-kDa and 92-kDa type IV collagenases) in HaCaT keratinocytes exposed to interleukin-1α (IL-1α) as a skin inflammation model. METHODS: MMP activity in cell conditioned medium was assayed by gelatin zymography, while NF-kB and MAP kinase activations were evaluated by Western blotting. RESULTS: IL-1α (10â¯ng/ml) upregulated MMP-9 but not MMP-2 in HaCaT cells. The extract, used at 2.3, 4.6 and 9.3⯵g/ml, had no effect, but in combination with IL-1α showed MMP-9 inhibition at the lowest dose and increased upregulation at the highest one. AKBA alone, at the same concentrations (corresponding to 5, 10, and 20⯵M), did not stimulate MMP-9, but together with IL-1α induced an increased upregulation at the lowest dose that progressively disappeared at higher doses. WB analysis showed that IL-1α induced phosphorylation of NF-κB p65, while AKBA abolished this effect at 20⯵M, but conversely increased it at 5⯵M. Screening of MAP kinase phosphorylation showed a combined activation of IL-1α/AKBA on JNK, while the JNK inhibitor SP600125 abolished MMP-9 upregulation induced by IL-1α/AKBA. CONCLUSION: The enhancing effect of IL-1α/AKBA on MMP-9 at low AKBA concentration seems to involve the activation of JNK-mediated NF-κB pathway. Conversely, the extract inhibits the IL-1α effect at low doses, but not at higher ones, where AKBA and possibly other ß-boswellic acids reach concentrations that potentiate the effect of IL-1α. The extract at low doses could protect the skin against degenerative processes of extracellular matrix, while keto-ß-boswellic acids seem unsuitable for this purpose.
Assuntos
Boswellia/química , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Queratinócitos/efeitos dos fármacos , Metaloproteinase 9 da Matriz/metabolismo , Triterpenos/farmacologia , Linhagem Celular , Ativação Enzimática/efeitos dos fármacos , Humanos , Interleucina-1alfa/metabolismo , Interleucina-1alfa/farmacologia , Queratinócitos/metabolismo , NF-kappa B/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Resinas Vegetais/química , Pele/citologia , Regulação para Cima/efeitos dos fármacosRESUMO
During and after spaceflight astronauts experience neurophysiological alterations. To investigate if the impairment observed might be traced back to cytomorphology, we undertook a ground based research using a random positioning machine (clinostat) as a simulation method for microgravity. The outcome of the study was represented by cytoskeletal changes occurring in cultured glial cells (C(6) line) after 15 min, 30 min, 1 h, 20 h and 32 h under simulated microgravity. Glia is fundamental for brain function and it is essential for the normal health of the entire nervous system. Our data showed that after 30 min under simulated microgravity the cytoskeleton was damaged: microfilaments (F-actin) and intermediate filaments (Vimentin, Glial Fibrillary Acidic Proteins GFAP) were highly disorganised, microtubules (alpha-tubulin) lost their radial array, the overall cellular shape was deteriorated, and the nuclei showed altered chromatin condensations and DNA fragmentation. This feature got less dramatic after 20 h of simulated microgravity when glial cells appeared to reorganise their cytoskeleton and mitotic figures were present. The research was carried out by immunohistochemistry using antibodies to alpha-tubulin, vimentin and GFAP, and cytochemical labelling of F-actin (Phalloidin-TRIC). The nuclei were stained with propidium iodide or 4,6-diamidino-2-phenylindole dihydrochloride (DAPI). The cells were observed at the conventional and/or the confocal laser scanning microscope. Samples were also observed at the scanning electron microscope (SEM). Our data showed that in weightlessness alterations occur already visible at the scale of the single cell; if this may lead to the neurophysiological problems observed in flight is yet to be established.
Assuntos
Sistema Nervoso Central/patologia , Citoesqueleto/patologia , Neuroglia/patologia , Enjoo devido ao Movimento em Voo Espacial/fisiopatologia , Ausência de Peso/efeitos adversos , Actinas/metabolismo , Actinas/ultraestrutura , Animais , Apoptose/fisiologia , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Núcleo Celular/ultraestrutura , Tamanho Celular/fisiologia , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/fisiopatologia , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Imunofluorescência , Proteína Glial Fibrilar Ácida/metabolismo , Proteína Glial Fibrilar Ácida/ultraestrutura , Filamentos Intermediários/metabolismo , Filamentos Intermediários/patologia , Filamentos Intermediários/ultraestrutura , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microtúbulos/metabolismo , Microtúbulos/patologia , Microtúbulos/ultraestrutura , Mitose/fisiologia , Neuroglia/metabolismo , Neuroglia/ultraestrutura , Ratos , Rotação/efeitos adversos , Enjoo devido ao Movimento em Voo Espacial/patologia , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/ultraestrutura , Células Tumorais Cultivadas , Vimentina/metabolismo , Vimentina/ultraestrutura , Simulação de Ausência de PesoRESUMO
Visual observations and videos of Chionodraco hamatus icefish at the "Acquario di Genova" and histological analyses of congeneric species C. hamatus and C. rastrospinosus adults sampled in the field provided new anatomical and behavioral information on the reproductive biology of these white blooded species that are endemic to the High-Antarctic region. During the reproductive season, mature males of both species, which are different from females and immature males, display fleshy, club-like knob modifications of their anal fin that consisted of a much thicker epithelium. Histology indicated that the knobs were without any specialized glandular or sensorial organization, thus suggesting a mechanical and/or ornamental role of the modified anal fin. In addition, the occurrence of necrotic regions at the base of the thickened epithelium and the detachment of the knobs in post-spawning C. hamatus males indicated the temporary nature of the knobs. The role of these structures was confirmed as mechanical and was clarified using visual observations and videos of the behavior of two C. hamatus during a reproductive event that occurred in an exhibit tank at the "Acquario di Genova". The reproductive process included pre-spawning activity, preparation of the nest, egg guarding and successfully ended with egg hatching. When the spawning event approached, the male prepared the nest. The nest was constructed on an accurately selected bottom surface, which was flattened and maintained free from sand or debris by a combination of radial body movements and continuous anal fin sweeping, thus demonstrating the important mechanical/abrasive function of the anal fin knobs. The present data are the first records of active nesting in icefish and clarify the meaning of dimorphic temporary structures, whose function would have been difficult to obtain in the field.
Assuntos
Nadadeiras de Animais/anatomia & histologia , Comportamento de Nidação , Perciformes/fisiologia , Animais , Regiões Antárticas , Feminino , Masculino , Perciformes/anatomia & histologia , Caracteres Sexuais , Gravação em VídeoRESUMO
Sea urchins are echinoderms, marine invertebrates found at the base of the deutorostome lineage, which show separate sexes and are external spawners. In the sea urchin, efficient regulation of water homeostasis is essential for many biological processes such as cellular respiration, normal fertilization and correct embryo growth. In order to clarify some of these processes, the present study reports on the identification and function of aquaporin proteins in the sea urchin. Our results show, by immunoblot, immunoelectron microscopy and immunofluorescence analysis, the presence of aquaporin1- and aquaporin3-like proteins in virgin eggs and in early embryogenesis of Paracentrotus lividus and, by using known inhibitors of aquaporin functions, the functional and relevant role of aquaporin-3 in the fertilization process. AQP3 in particular seems to play a crucial role in high velocity water flux formations involved in the detachment of the vitelline layer during the slow block of polyspermy, while the presence of AQP1 and the increase of AQP3 in the first phase of the P. lividus developmental cycle, suggest their involvement in the appropriate homeostasis for embryo development.
Assuntos
Aquaporina 1/análise , Aquaporina 3/análise , Oócitos/metabolismo , Paracentrotus/embriologia , Paracentrotus/metabolismo , Animais , Aquaporina 1/metabolismo , Aquaporina 3/metabolismo , Oócitos/crescimento & desenvolvimentoRESUMO
The Amphibalanus amphitrite barnacle is a sessile marine crustacean and a major constituent of benthic as well as intertidal communities. A. amphitrite is also an important component of biofouling on artificial substrates. The role of nitric oxide (NO) was recently observed in the settlement of this species. In this work, we used immunohistochemical and histoenzymatic methods to investigate, for the first time, the presence and distribution of NO synthetic enzymes (NOS) in the competent-for-settlement cyprid of A. amphitrite. NOS-like immunoreactivity was observed in various regions of the cyprid: gut mucosa, mantel epithelium, thoracic muscle, and abductor muscles. Intense immunoreactivity was also present in the cement gland and oil cells, while widespread immunoreactivity was observed in the compound eye. NADPH-diaphorase method was used to provide further data and understand NOS-distribution. The results show that NOS is likely to be present in structures - such as muscles and cement gland - which are key for settlement.
Assuntos
Óxido Nítrico Sintase/metabolismo , Thoracica/enzimologia , Animais , NADPH Desidrogenase/metabolismo , Especificidade de ÓrgãosRESUMO
The mucosa covering the tongue of the Chimaera monstrosa has been investigated with histological and immunohistochemical methods allowing to describe, for the first time, gustatory structures (taste buds) in this subclass of cartilaginous fish. G-protein-alpha-subunit-inhibitory-like (Gαi-like) immunoreactivity has been detected in the taste buds of C. monstrosa, as described in other vertebrates. In order to gain confidence on the antiserum used, able to recognize three Gαi proteins in mammals, alignments of the antigenic sequence in mammals and other vertebrates were performed. The data were used for a research of putative genes in the genome of the holocephalan Callorhinchus milii, to date the only cartilaginous fish with a sequenced genome; the highlighted sequences could suggest the presence of all three genes (gnai1, gnai2 and gnai3) in holocephalans. The sequences of the predicted proteins present a high identity with the mammalian proteins.
Assuntos
Peixes/fisiologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Papilas Gustativas/fisiologia , Sequência de Aminoácidos , Animais , Epitélio/inervação , Epitélio/fisiologia , Feminino , Genoma , Imuno-Histoquímica , Masculino , Dados de Sequência Molecular , Papilas Gustativas/metabolismo , Língua/inervação , Língua/fisiologiaRESUMO
Nitric oxide is a regulative molecule with important roles in the olfactory system of vertebrates. Chondrichtyans have a key position in vertebrate evolution and nothing is known about nitric oxide in their olfactory system. Aim of this work was to investigate the neuronal nitric oxide synthase (nNOS) immunoreactivity in the olfactory system of the shark Scyliorhinus canicula. Because nitric oxide is often related to GABA in the olfactory system, also the distribution of GABA and its synthesis enzyme GAD has been investigated. In the olfactory epithelium scattered cells in the basal and medial zone of the epithelium thickness presented nNOS-like immunoreactivity. In the olfactory bulb the nNOS-like immunoreactivity has been highlighted in nerve fibers around some blood vessels and in scattered GABAergic granule cells. The presence of nNOS in the olfactory system of S. canicula is overall lesser than that described in other vertebrates, even if nitric oxide probably keeps some essential functions.
Assuntos
Neurônios/enzimologia , Óxido Nítrico Sintase Tipo I/análise , Óxido Nítrico Sintase Tipo I/metabolismo , Bulbo Olfatório/química , Bulbo Olfatório/enzimologia , Mucosa Olfatória/química , Mucosa Olfatória/enzimologia , Animais , Feminino , Masculino , Bulbo Olfatório/citologia , Mucosa Olfatória/citologia , TubarõesRESUMO
The acorn barnacle Balanus amphitrite is a marine crustacean with six nauplius and one cyprid larval stages and a sessile adult, that represent one of the main constituents of sea biofouling. The cyprid is the last larval stage, specialized for settlement, and the study of its biology is interesting also in the frame of antifouling strategies. In this study, a novel approach to the neurobiology of B. amphitrite cyprid has undertaken, studying immunohistochemically the distribution of some G-protein α subunits (Gαs, Gαo Gαi, and Gαq) on B. amphitrite cyprid. Gαs-like immunoreactivity was observed in the intestinal mucosa, oral cone, epithelial cells along the outer face of the mantle and thorax; Gαo into the fibers of the neuropile of the central nervous system; Gαi in oil cells, epithelial cells, and limbs and thorax muscles; Gαq was not detected. The results suggest the involvement of the G-protein α subunits in different tissues and functions that seem to be in agreement with the distribution of the ones from the same class of G-proteins in vertebrates.
Assuntos
Proteínas de Ligação ao GTP/análise , Thoracica/química , Estruturas Animais/química , Animais , Imuno-Histoquímica , Larva/química , Subunidades Proteicas/análiseRESUMO
Hormonal changes in humans during spaceflight have been demonstrated but the underlying mechanisms are still unknown. To clarify this point thyroid and testis/epididymis, both regulated by anterior pituitary gland, have been analyzed on long-term space-exposed male C57BL/10 mice, either wild type or pleiotrophin transgenic, overexpressing osteoblast stimulating factor-1. Glands were submitted to morphological and functional analysis.In thyroids, volumetric ratios between thyrocytes and colloid were measured. cAMP production in 10(-7)M and 10(-8)M thyrotropin-treated samples was studied. Thyrotropin receptor and caveolin-1 were quantitized by immunoblotting and localized by immunofluorescence. In space-exposed animals, both basal and thyrotropin-stimulated cAMP production were always higher. Also, the structure of thyroid follicles appeared more organized, while thyrotropin receptor and caveolin-1 were overexpressed. Unlike the control samples, in the space samples thyrotropin receptor and caveolin-1 were both observed at the intracellular junctions, suggesting their interaction in specific cell membrane microdomains.In testes, immunofluorescent reaction for 3ß- steroid dehydrogenase was performed and the relative expressions of hormone receptors and interleukin-1ß were quantified by RT-PCR. Epididymal sperm number was counted. In space-exposed animals, the presence of 3ß and 17ß steroid dehydrogenase was reduced. Also, the expression of androgen and follicle stimulating hormone receptors increased while lutenizing hormone receptor levels were not affected. The interleukin 1 ß expression was upregulated. The tubular architecture was altered and the sperm cell number was significantly reduced in spaceflight mouse epididymis (approx. -90% vs. laboratory and ground controls), indicating that the space environment may lead to degenerative changes in seminiferous tubules.Space-induced changes of structure and function of thyroid and testis/epididymis could be responsible for variations of hormone levels in human during space missions. More research, hopefully a reflight of MDS, would be needed to establish whether the space environment acts directly on the peripheral glands or induces changes in the hypotalamus-pituitary-glandular axis.
Assuntos
Voo Espacial , Testículo/citologia , Testículo/metabolismo , Glândula Tireoide/citologia , Glândula Tireoide/metabolismo , Animais , Western Blotting , Caveolina 1/metabolismo , AMP Cíclico/biossíntese , Imunofluorescência , Imuno-Histoquímica , Interleucina-1beta/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Esteroides/metabolismo , Receptores da Tireotropina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Contagem de EspermatozoidesRESUMO
The complex control of food intake and energy metabolism in mammals relies on the ability of the brain to integrate multiple signals indicating the nutritional state and the energy level of the organism and to produce appropriate responses in terms of food intake, energy expenditure, and metabolic activity. Central regulation of feeding is organized as a long-loop mechanism involving humoral signals and afferent neuronal pathways to the brain, processing in hypothalamic neuronal circuits, and descending commands using vagal and spinal neurons. Sensor mechanisms or receptors sensitive to glucose and fatty acid metabolism, neuropeptide and cannabinoid receptors, as well as neurotransmitters and neuromodulators synthesized and secreted within the brain itself are all signals integrated in the hypothalamus, which therefore functions as an integrator of signals from central and peripheral structures. Homeostatic feedback mechanisms involving afferent neuroendocrine inputs from peripheral organs, like adipose tissue, gut, stomach, endocrine pancreas, adrenal, muscle, and liver, to hypothalamic sites thus contribute to the maintenance of normal feeding behavior and energy balance. In addition to transcriptional events, peripheral hormones may also alter firing and/or connection (synaptology) of hypothalamic neuronal networks in order to modulate food intake. Moreover, intracellular energy sensing and subsequent biochemical adaptations, including an increase in AMP-activated protein kinase activity, occur in hypothalamic neurons. Understanding the regulation of appetite is clearly a major research effort but also seems promising for the development of novel therapeutic strategies for obesity.
Assuntos
Mamíferos/fisiologia , Animais , Metabolismo Energético , Comportamento Alimentar , Humanos , Hipotálamo/metabolismo , Sinapses/metabolismoRESUMO
Chimera monstrosa (rabbit fish) like other holocephalans is a rare, delicate deep sea fish. Owing to the difficulty of sampling individuals in good shape, there is a paucity of information available on the morphology and physiology of this species especially concerning reproduction. In holocephalans, a hypothalamus-pituitary-gonadal axis has been postulated and a GnRH molecule identical to cGnRH II has been identified. The aim of the present study was to correlate the presence of steroidogenic enzymes in the ovarian follicles with the presence of GnRH in the hypothalamus. Estrogens, the steroids that trigger the accumulation of yolk (vitellogenesis) in the oocytes are synthesized by the somatic cells of the follicle in the vitellogenic stages via a cascade of steroid dehydrogenases involving 3 beta-hydroxysteroid-dehydrogenase (3 beta-HSD; in the inner thecal layer) and aromatase cytochrome (P450; granulosa layer). Our results showed that 3 beta-HSD is present concomitant with the presence of cGnRH II in the preoptic area and in the ventral hypothalamus. Another form of immunoreactive GnRH, mGnRH is also present in the brain of C. monstrosa. It is localized in the ventral telencephalon and in the midbrain caudal diencephalon (boundary between ventral thalamus and tegmentum of the mesencephalon). This form of GnRH is probably correlated with sexual behaviour.
Assuntos
Química Encefálica/fisiologia , Peixes/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Oócitos/crescimento & desenvolvimento , 3-Hidroxiesteroide Desidrogenases/metabolismo , Animais , Encéfalo/anatomia & histologia , Química Encefálica/efeitos dos fármacos , Citoplasma/metabolismo , Feminino , Imunoquímica , Imuno-Histoquímica , Metabolismo dos Lipídeos/fisiologia , Folículo Ovariano/anatomia & histologia , Folículo Ovariano/fisiologia , Ovário/anatomia & histologia , Ovário/crescimento & desenvolvimentoRESUMO
A galanin (GAL)-like peptidergic system was investigated in the brain of Anguilla anguilla subjected to hyperosmolar and hypoosmolar conditions, by using antisera raised against porcine 1-29 GAL. A group of immunoreactive perikaria was identified in the periventricular hypothalamus, in the ventral thalamus, in the pretectal areas and in the optic tectum. Immunoreactive perikaria were present in the nucleus lateralis of the torus semicircularis in seawater (SW) adapted eels, and were absent in the freshwater (FW) adapted eels. Galaninergic fibres were observed in many areas of the brain. The immunoreactive perikaria and fibres, when localised in the same areas, were more strongly labelled and numerous in the SW adapted eels in comparison to the FW adapted animals. GAL-specific binding sites, investigated by autoradiography using iodinated porcine GAL, occurred in several regions of the brain, in particular in the dorsal telencephalon, in the dorsal thalamus and in the torus semicircularis, where a high density of binding sites was observed in the SW adapted eels. Conversely, a higher density of binding sites was observed in the caudal substantia reticularis and in the corpus cerebelli in the FW adapted eels. We conclude that different distributions and intensity in immunoreactive elements occur in response to the two environmental conditions.