ABSTRACT
The mandible condylar process cartilage (CP) of Wistar rats is a secondary cartilage and acts as a mandibular growth site. This phenomenon depends on adequate proteins intake and hormone actions, including insulin. Objectives The present study evaluated the morphological aspects and the expression of the insulin receptor (IR) in the cartilage of the condylar process (CP) of rats subjected to protein undernourishment. Material and Methods The nourished group received a 20% casein diet, while the undernourished group (U) received a 5% casein diet. The re-nourished groups, R and RR, were used to assess the effects of re-nutrition during puberty and adulthood, respectively. CPs were processed and stained with picro-sirius red, safranin-O and azocarmine. Scanning electron microscopy and immunohistochemistry were also performed. Results The area of the CP cartilage and the number of cells in the chondroblastic layer decreased in the U group, as did the thickness of the CP layer in the joint and hypertrophic layer. Renourishment during the pubertal stage, but not during the adult phase, restored these parameters. The cell number was restored when re-nutrition occurred in the pubertal stage, but not in the adult phase. The extracellular matrix also decreased in the U group, but was restored by re-nutrition during the pubertal stage and further increased in the adult phase. IR expression was observed in all CPs, being higher in the chondroblastic and hypertrophic cartilage layers. The lowest expression was found in the U and RR groups. Conclusions Protein malnutrition altered the cellularity, the area, and the fibrous cartilage complex, as well as the expression of the IRs. .
Subject(s)
Animals , Mice , Anti-Inflammatory Agents, Non-Steroidal/metabolism , Cyclooxygenase 1/metabolism , /metabolism , Cyclooxygenase Inhibitors/metabolism , Piroxicam/analogs & derivatives , Thiazines/metabolism , Thiazoles/metabolism , Amino Acid Substitution , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Arginine/chemistry , Arginine/genetics , Arginine/metabolism , Binding Sites , Catalytic Domain , Cyclooxygenase 1/chemistry , Cyclooxygenase 1/genetics , /chemistry , /genetics , Cyclooxygenase Inhibitors/chemistry , Hydrogen Bonding , Leucine/chemistry , Leucine/genetics , Leucine/metabolism , Mutation , Piroxicam/chemistry , Piroxicam/metabolism , Protein Structure, Secondary , Serine/chemistry , Serine/genetics , Serine/metabolism , Thiazines/chemistry , Thiazoles/chemistry , Tyrosine/chemistry , Tyrosine/genetics , Tyrosine/metabolism , WaterABSTRACT
O século XX foi caracterizado pelo aumento na longevidade do ser humano, sendo que a expectativa de vida equivale a quase o dobro da idade alcançada no início do século. O envelhecimento é um processo progressivo e inevitável que ocorre com o avanço da idade, independentemente de doença, estilo de vida ou fatores ambientais. Está acompanhado de modificações morfofisiológicas que determinam à perda gradual da capacidade de adaptação do indíviduo ao meio ambiente. No trato gastrointestinal (TGI), o processo de envelhecimento pode provocar alterações morfofuncionais significativas nos plexos entéricos, ocasionando maior incidência de processos patológicos. A regulação da motilidade do TGI é controlada principalmente pelos neurônios mioentéricos e alterações na densidade destes neurônios podem resultar em modificações na freqüência e amplitude da contração intestinal. Dessa forma, este trabalho teve como objetivo avaliar a densidade dos neurônios mioentéricos NADPH-diaforase positivos do duodeno de ratos Wistar durante o processo de envelhecimento. Para tanto, foram utilizados 15 ratos machos da linhagem Wistar, divididos em três grupos (n=5/grupo): C6 (animais com seis meses de idade); C12 (animais com doze meses de idade); C18 (animais de dezoito meses). Os animais dos grupos C12 e C18 aos seis meses de idade foram transferidos para o biotério setorial, onde permaneceram até aos 12 e 18 meses respectivamente, sob condições ambientais controladas de temperatura e de iluminação e água ad libitum. Após o período experimental todos os animais foram submetidos a eutanásia e os duodenos foram coletados e processados pela técnica histoquímica da NADPH-diaforase. Ao compararmos os grupos C6, C12 e C18 verificou-se uma diminuição na densidade neuronal (número de neurônios/mm²) com o envelhecimento, entretanto esta diferença só foi significativa (p<0,05) nos animais com 18 meses de idade. Essa redução na densidade de neurônio nitrérgicos também foi relatada na literatura no duodeno e em outros segmentos intestinais, em diferentes espécies animais com o avanço da idade. Tendo em vista tais alterações, se faz necessário o desenvolvimento de intervenções terapêuticas, que visem minimizar os efeitos do envelhecimento, melhorando desta forma a qualidade de vida da população idosa.
The twentieth century was characterized by increasing in human longevity, being life expectancy equivalent to practically twice of the age reached at the beginning of the century. The aging is a progressive and inevitable process that occurs with age and does not depend of diseases, lifestyle or environmental factors; it is accompanied by morph physiological changes that determine the progressive loss of individual´s ability to adapt to the environment. In the Gastrointestinal Tract (GIT), the aging process can provoke significant morpho functional changes in the enteric plexuses causing higher incidence of pathological processes. The GIT motility is primarily controlled by myenteric neurons, thus, changes in the density of these neurons may result in changes in the frequency and amplitude of intestinal contraction. Therefore, the aim of this work to evaluate the density of myenteric neurons NADPH-diaforase positive in the duodenum of Wistar rats during aging process. Fifteen male wistar rats were used in the experiment. The animals were divided in three groups of five animals (n=5) as following: C6 (animals aged six months); C12 (animals aged twelve months); C18 (animals aged eighteen months). The animals from the groups C12 and C18 were previously transferred to vivarium, under environmental conditions of controlled temperature and light and water ad libitum, since have reached six months to twelve and eighteen months respectively. After experimental period, all animals were euthanized and the duodenum were collected and processed for standard histochemical NADPH-diaforase technique. As a result, a decrease in the neuronal density (mm²) at the time with aging was observed in the three groups, C6, C12 and C18, however, this difference was remarkable (p>0,05) from twelve months old. This reduction in the density of nitrergic neurons was previously reported in the duodenum and other intestinal segments of different animals under aging process. Based in such alterations, were believed that there is a need of the development of therapies that minimize the effects of aging, thus, improving the quality of elderly life.