RESUMO
Sea anemones have a structurally simple nervous system that controls behaviors like feeding, locomotion, aggression, and defense. Specific chemical and tactile stimuli are transduced by ectodermal sensory cells and transmitted via a neural network to cnidocytes and epithelio-muscular cells, but the nature of the neurotransmitters operating in these processes is still under discussion. Previous studies demonstrated an important role of peptidergic transmission in cnidarians, but during the last decade the contribution of conventional neurotransmitters became increasingly evident. Here, we used immunohistochemistry on light and electron microscopical preparations to investigate the localization of glutamate and GABA in tentacle cross-sections of the sea anemone Phymactis papillosa. Our results demonstrate strong glutamate immunoreactivity in the nerve plexus, while GABA labeling was most prominent in the underlying epithelio-muscular layer. Immunoreactivity for both molecules was also found in glandular epithelial cells, and putative sensory cells were GABA positive. Under electron microscopy, both glutamate and GABA immunogold labeling was found in putative neural processes within the neural plexus. These data support a function of glutamate and GABA as signaling molecules in the nervous system of sea anemones.
Assuntos
Estruturas Animais/metabolismo , Ácido Glutâmico/imunologia , Anêmonas-do-Mar/anatomia & histologia , Anêmonas-do-Mar/metabolismo , Ácido gama-Aminobutírico/imunologia , Estruturas Animais/anatomia & histologia , Estruturas Animais/citologia , Estruturas Animais/ultraestrutura , Animais , Imuno-Histoquímica , Anêmonas-do-Mar/citologia , Anêmonas-do-Mar/ultraestruturaRESUMO
The immune, endocrine and nervous systems are closely interrelated, which allows the organism to respond to different types of stress such as infection. Chronic infectious and inflammatory conditions are often accompanied by an impaired reproductive function. Leptin, a hormone produced by adipose tissue, exerts a regulatory function on the reproductive axis. It has homology with other proinflammatory cytokines and could be modified by lipopolysaccharide (LPS). Therefore, these studies were designed to investigate the effect of LPS administration on the neuroendocrine mechanisms involved in the regulation of the reproductive axis during sexual maturation. Fifteen- and 30-day-old female rats were injected with a single dose of LPS 250 microg/kg (i.p.) and then nitric oxide synthase (NOS) activity, hypothalamic excitatory/inhibitory amino acids and Gn-RH content, serum LH and leptin concentration were studied. In 15-day-old female rats LPS treatment did not modify hypothalamic inducible (iNOS) and constitutive (cNOS) NOS activity, Gn-RH, glutamate (GLU) and GABA content. Also serum LH and leptin levels were not modified. In 30-day-old rats LPS increased iNOS and cNOS activity (p < 0.001) and hypothalamic Gn-RH content (p < 0.001). At this age hypothalamic GABA content was significantly decreased (p < 0.001) without changes in GLU content, and serum LH (p < 0.001) and leptin (p < 0.0001) decreased significantly. In summary, current studies have demonstrated that LPS administration to 15- and 30-day-old female rats results in a different response of the hypothalamus-pituitary-gonadal axis and of the adipose tissue, demonstrating an ontogenic response of the immune-neuroendocrine system to LPS administration.
Assuntos
Infecções Bacterianas/imunologia , Leptina/imunologia , Neuroimunomodulação/imunologia , Sistemas Neurossecretores/imunologia , Reprodução/imunologia , Maturidade Sexual/imunologia , Tecido Adiposo/imunologia , Tecido Adiposo/metabolismo , Envelhecimento/imunologia , Envelhecimento/metabolismo , Animais , Feminino , Ácido Glutâmico/imunologia , Ácido Glutâmico/metabolismo , Hormônio Liberador de Gonadotropina/imunologia , Hormônio Liberador de Gonadotropina/metabolismo , Sistema Hipotálamo-Hipofisário/imunologia , Sistema Hipotálamo-Hipofisário/metabolismo , Hipotálamo/imunologia , Hipotálamo/metabolismo , Mediadores da Inflamação/farmacologia , Leptina/sangue , Lipopolissacarídeos/farmacologia , Hormônio Luteinizante/sangue , Hormônio Luteinizante/imunologia , Sistemas Neurossecretores/metabolismo , Sistemas Neurossecretores/fisiopatologia , Óxido Nítrico Sintase/imunologia , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Wistar , Estresse Fisiológico/imunologia , Estresse Fisiológico/metabolismo , Estresse Fisiológico/fisiopatologia , Regulação para Cima/imunologia , Ácido gama-Aminobutírico/imunologia , Ácido gama-Aminobutírico/metabolismoRESUMO
Background: Islet cell-specific autoantibodies such as islet cell antibody (ICA), antiinsulin (IAA), anti-glutamic acid decarboxylase (GAD) and anti-tyrosine phosphatase (IA2) can be present in patients with type I diabetes. Breast feeding duration and the early exposure to milk substitutes are environmental factors associated to etiology of type 1 diabetes. Aim To study the frequency of the anti-GAD, anti-IA-2 e ICA antibodies in Chilean type 1 diabetic patients and determine the possible modulator effect of the breast feeding. Patients and methods: One hundred thirty four type I diabetic patients, aged one to 15 years old, were studied at the moment of their diagnosis. Patients were classified according to the duration of exclusive breast feeding. IA-2 and GAD were determined by radio immuno assay and ICA by means of indirect immunofluorescence. Results: Subjects with three months or less and those with more than three months of breast feeding were positive for ICA in 78.8 and 90.6 per cent of cases respectively, for GAD in 75 and 54.6 per cent of cases respectively (p=0.024) and for IA-2 in 73 and 43.8 per cent of cases respectively (p=0.001). All three antibodies were positive in 53.9 and 21.8 per cent of children with less or more than three months of breast feeding (p=0.001). Conclusion: Both IA-2 and GAD antibodies are less frequently positive in type 1 diabetic patients who have been breast fed for more than three months. These findings suggest a possible attenuating role of exclusive breast feeding on pancreatic aggression events in patients with type 1 diabetes
Assuntos
Humanos , Pré-Escolar , Lactente , Criança , Masculino , Feminino , Autoanticorpos/imunologia , Aleitamento Materno , Diabetes Mellitus Tipo 1/imunologia , Autoimunidade/imunologia , Ilhotas Pancreáticas/imunologia , Ácido Glutâmico/imunologia , Anticorpos Anti-Insulina/imunologia , Proteínas Tirosina Fosfatases/imunologiaRESUMO
Objetivo. Conocer la frecuencia de autoanticuerpos a la descarboxilasa del ácido glutámico (GAD) en niños mexicanos con diabetes mellitus tipo 1 (DM 1) por un método de radioligando (RBA). Material y métodos. Se determinaron anticuerpos a GAD en 140 niños mestizos con DM 1, 66 niñas (47.14 por ciento) y 74 niños (52.8 por ciento), con promedio de 11.7 ñ 3.55 años, entre 1.10 a 18.5 años de edad. Todos estaban en tratamiento con insulina de acción intermedia y algunos de ellos con combinación de insulina de acción rápida. El promedio de la evolución del padecimiento fue de 3.11 ñ 2.94 años, entre un mes a 14.5 años. Previo consentimiento informado se tomó la muestra de 5.0 mL de sangre, que se centrifugó de inmediato y el suero se conservó congelado a -20º C hasta su procesamiento por un equipo comercial de RBA. Resultados. Los anticuerpos a GAD resultaron positivos en 76 pacientes con DM 1 (54.28 por ciento) con valores entre 1.11 a 156.73 U/mL y negativos en 64 (45.71 por ciento). En 19 pacientes con anticuerpos a GAD positivos, se repitió la misma determinación y los valores se encontraron entre 1.38 a 156.62 U/mL. En un grupo control inicial de 25 voluntarios no relacionados, igualados en edad y sexo, la determinación de los anticuerpos fue negativa en todos ellos. Conclusiones. La frecuencia de anticuerpos a GAD en estos pacientes fue inferior a la informada en pacientes europeos con DM 1, pero semejante a la de asiáticos. Estos resultados apoyan la heterogeneidad de la etiopatogenia de la DM 1 en diferentes grupos étnicos.