RESUMO
Insulin-like growth factor-I (IGF-I), also known as somatomedin-C, is an important mediator of growth regulation. Serum concentrations of IGF-I and proteoglycan synthesis rates in the tibial epiphysis, an estimate of the biological response to IGF-I in a target tissue, were compared in weanling Wistar rats fed ad libitum (group 1) and with 50% restriction (group 2) with the regional diet of São Paulo State (RDSPS--a mean diet consumed by low-income families with rice, beans, sugar, meat, milk, fruits and other vegetables) and in pair-fed animals fed with casein diets (groups 3 and 4). Data are reported as mean +/- SD for 8 rats in each group. Proteoglycan synthesis rates (cpm/mg) were significantly higher in rats fed with the RDSPS-based diet (groups 1 and 2: 210.8 +/- 58.8, 136.6 +/- 17.6) than in pair-fed animals fed with an 11% casein diet (groups 3 and 4: 62.9 +/- 11.6, 37.7 +/- 13.7) and in control animals fed ad libitum with a 20% casein diet (group 5: 58.1 +/- 22.7). Furthermore, these rates were higher in animals fed ad libitum than in those fed with the same diets but with 50% restriction. However, similar differences between groups 1 to 4 were not observed in serum concentrations (ng/100 microliters) of IGF-I (group 1: 44.1 +/- 7.1; group 2: 40.8 +/- 3.8; group 3: 46.0 +/- 3.6; group 4: 41.6 +/- 3.4, and group 5: 63.2 +/- 7.8). These results suggest that serum IGF-I levels are not reliable indicators of IGF-I status in this experimental model.
Assuntos
Envelhecimento/metabolismo , Caseínas/administração & dosagem , Dieta , Proteínas Alimentares/administração & dosagem , Fator de Crescimento Insulin-Like I/análise , Proteoglicanas/biossíntese , Animais , Brasil , Epífises/metabolismo , Proteoglicanas/análise , Ratos , Ratos Wistar , Tíbia , DesmameRESUMO
Insulin-like growth factor-I (IGF-I), also known as somatomedin-C, is an important mediator of growth regulation. Serum concentrations of IGF-I and proteoglycan synthesis rates in the tibial epiphysis, an estimate of the biological response to IGF-I in a target tissue, were compared in weanling Wistar rats fed ad libitum (group 1) and with 50% restriction (group 2) with the regional diet of Säo Paulo State (RDSPS--a mean diet consumed by low-income families with rice, beans, sugar, meat, milk, fruits and other vegetables) and in pair-fed animals fed with casein diets (groups 3 and 4). Data are reported as mean +/- SD for 8 rats in each group. Proteoglycan synthesis rates (cpm/mg) were significantly higher in rats fed with the RDSPS-based diet (groups 1 and 2: 210.8 +/- 58.8, 136.6 +/- 17.6) than in pair-fed animals fed with an 11% casein diet (groups 3 and 4: 62.9 +/- 11.6, 37.7 +/- 13.7) and in control animals fed ad libitum with a 20% casein diet (group 5: 58.1 +/- 22.7). Furthermore, these rates were higher in animals fed ad libitum than in those fed with the same diets but with 50% restriction. However, similar differences between groups 1 to 4 were not observed in serum concentrations (ng/100 microliters) of IGF-I (group 1: 44.1 +/- 7.1; group 2: 40.8 +/- 3.8; group 3: 46.0 +/- 3.6; group 4: 41.6 +/- 3.4, and group 5: 63.2 +/- 7.8). These results suggest that serum IGF-I levels are not reliable indicators of IGF-I status in this experimental model
Assuntos
Animais , Envelhecimento/metabolismo , Caseínas/administração & dosagem , Dieta , Proteínas Alimentares/administração & dosagem , Fator de Crescimento Insulin-Like I/análise , Proteoglicanas/biossíntese , Brasil , Epífises/metabolismo , Proteoglicanas/análise , Ratos , Ratos Wistar , Tíbia , DesmameRESUMO
Serum somatomedins, or insulin-like growth factor(s) (IGF), originally characterized as primarily GH-dependent peptides, were found to also be dependent on insulin levels and nutritional status. Four properties characterize somatomedin peptides: their concentrations in serum are growth hormone dependent; they possess insulin actions in extraskeletal tissues; they promote the incorporation of sulfate into proteoglycans of cartilage; and they stimulate DNA synthesis and cell multiplication in certain types of cultured cells. Reduced somatomedin C levels are found in children with severe protein-energy malnutrition. Plasma concentration of growth hormone and cortisol are both elevated and there are low levels of insulin and somatomedin C. There is evidence that the ability of somatomedin C to stimulate cartilage is modulated by somatomedin inhibitor, factor that may act to limit growth in conditions of hormonal and/or nutritional deficiency. Dietary energy and protein appears to be particularly important for both generation of somatomedins and their action on growing cartilage. Measurement of somatomedins C concentration shows promise as a means for monitoring the response of malnourished patients and rats to nutrition repletion.
Assuntos
Crescimento , Estado Nutricional , Somatomedinas/metabolismo , Animais , Proteínas Alimentares/farmacologia , Humanos , Desnutrição Proteico-Calórica/sangue , Ratos , Somatomedinas/fisiologiaRESUMO
The effect of diet of São Paulo State on some biochemical parameters in the liver, brain and plasma of rats at weaning and 90 days was studied. The tissue parameters studied were the amounts of DNA, RNA and protein in the liver and brain. For the plasma were the total protein and albumin. Wistar rat were fed a 13% casein (control) and 13% protein of experimental diet since the gestation. In experimental diet weight at birth, weaning and 90 days were considerably reduced. A comparison of the data of the experimental rats in relation to the control group indicated that: a) organ weight, total organ DNA, RNA and protein were all reduced; b) no differences in total protein and albumin in plasma were observed between the control and the experimental group. These results suggest that the diet experimental is deficient in some nutrients (minerals, vitamins?) and affected the cellular development of brain and liver.
Assuntos
Peso Corporal , Alimentos Formulados , Tamanho da Ninhada de Vivíparos , Prenhez/metabolismo , Animais , Proteínas Sanguíneas/análise , Encéfalo/crescimento & desenvolvimento , Química Encefálica , DNA/análise , Feminino , Alimentos Formulados/análise , Crescimento , Fígado/análise , Fígado/crescimento & desenvolvimento , Masculino , Gravidez , RNA/análise , Ratos , Ratos EndogâmicosRESUMO
The objective of the present work was to study the influence of protein quantity and quality on some biochemical parameters in the liver, brain and plasma of rats at 51 days of age. This profile was sketched through the weight of the liver and brain and their content of DNA, RNA and protein and through the total amount of protein, the ratio NE/E and the activity of transaminase GOT and GPT in the plasma. During gestation and lactation, diets of 20% casein, 8% casein and 8% corn were used. At weaning, five experimental groups, with and without nutritional recuperation, were established. As a result, it was observed that the groups fed on a hypoprotein diet (8% casein or 8% corn) were the most seriously compromised in body weight and biochemical parameters with the group fed on corn being the most seriously affected. The animal which were recuperated nutritionally presented a net improvement in all of the parameters. However, the values describing the development of the body and organs in these groups remained inferior to those obtained in the control group. The success of reversibility will depend on the phase of development during which malnutrition occurred and the duration and intensity of the original deficit and the subsequent rehabilitation treatment. Organs in a phase of accelerated development will be especially sensitive to the irreversible effects of malnutrition.
Assuntos
Aminoácidos/metabolismo , Encéfalo/metabolismo , Crescimento , Fígado/metabolismo , Deficiência de Proteína/fisiopatologia , Animais , Peso Corporal , Encéfalo/patologia , Dieta , Fígado/patologia , Tamanho do Órgão , Deficiência de Proteína/metabolismo , Deficiência de Proteína/patologia , Ratos , Ratos EndogâmicosRESUMO
The influence of protein on some biochemical parameters in the liver, brain and plasma of rats at weaning was studied. The tissue parameters studied were the amounts of DNA, RNA and protein in the liver and brain. For the plasma, the parameters studied were the total amount of protein and the ratio of non-essential to essential amino acids (ratio NE/E). During the gestation and lactation period, the rats were divided into three groups according to the diet received: group 1, 20% casein; group 2, 8% casein; and group 3, 8% corn. As a result we can assert that groups 2 and 3, fed on hypoprotein diets, were seriously compromised in body weight and in the biochemical parameters and these alteration were enhanced by the corn diet. These results suggest that the alterations depend on the duration and intensity of the malnourishment and that the quality of the protein is an important factor to be considered.
Assuntos
Composição Corporal , Complicações na Gravidez , Deficiência de Proteína , Animais , Química Encefálica , DNA/análise , Proteínas Alimentares/administração & dosagem , Feminino , Retardo do Crescimento Fetal/etiologia , Transtornos do Crescimento/etiologia , Fígado/análise , Tamanho do Órgão , Gravidez , Proteínas/análise , RNA/análise , Ratos , Ratos Endogâmicos , DesmameRESUMO
The present study was undertaken to assess the effect of different levels of nutritional restriction during fetal life, suckling, and after weaning of the brain biochemical composition. At 41 days of age, the rats were killed and the brain was processed for analyses of DNA, RNA and protein. The results showed that the brain weights as well as DNA, RNA and protein brain contents were impaired by hypoprotein diet, and these alterations were enhanced by the corn diet.
Assuntos
Encéfalo/crescimento & desenvolvimento , Dieta/efeitos adversos , Desnutrição Proteico-Calórica/fisiopatologia , Animais , Peso Corporal , Química Encefálica , DNA/análise , Proteínas Alimentares/administração & dosagem , Feminino , Lactação , Masculino , Tamanho do Órgão , Gravidez , Desnutrição Proteico-Calórica/etiologia , RNA/análise , Ratos , Zea maysRESUMO
The goal of the present work was to reproduce in laboratory animals situations frequently observed in low-income population, such as the insufficient energetic ingestion associated with protein sources of inferior quality. Corn was chosen as the protein source of low biological value and casein as the reference protein. The latter was administered in adequate quantity (20%) or equal to that of the corn (10%). Several biochemical parameters and the amounts of DNA, RNA and protein in the liver of rats in a phase of rapid growth were studied. In result, we can attest that the group fed on corn were the most seriously compromised in body weight, liver weight and biochemical parameters with the group fed a restricted diet of corn being the most seriously affected. The results suggest that the alterations caused by ingestion of a balanced diet restricted in quantity were less accentuated that those observed when the diet was of corn "ad libitum".
Assuntos
Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Fígado/metabolismo , Deficiência de Proteína/metabolismo , Animais , Modelos Animais de Doenças , Alimentos Formulados , Fígado/análise , Fígado/fisiopatologia , Tamanho do Órgão , Deficiência de Proteína/fisiopatologia , Proteínas/análise , Ratos , Ratos EndogâmicosRESUMO
Procura-se reproduzir em animais de laboratorio situacoes observadas frequentemente em populacoes de baixa renda, tais como insuficiente ingestao energetica associada a fontes proteicas de qualidade inferior. Escolheu-se o milho como fonte protetica de baixo valor biologico e a caseina como proteina de referencia, sendo esta administrada em quantidade adequada (20%) ou igual a do milho (10%) . Estudaram-se alguns parametros bioquimicos e conteudos de DNA, RNA e proteina no figado de ratos em fase aguda de crescimento.Como resultados, podemos assinalar que os grupos alimentados com milho foram os mais comprometidos na avaliacao do peso corporeo, peso do figado e parametros bioquimicos, sendo que o grupo alimentado com milho em restricao foi o mais seriamente afetado. Os resultados sugerem que as alteracoes decorrentes da ingestao de dietas balanceadas em quantidade restrita, foram menos acentuadas do que aquelas observadas quando a dieta utilizada foi o milho "ad libitum"
Assuntos
Animais , Ratos , Proteínas Alimentares , Fígado , Deficiência de ProteínaRESUMO
Verificaram-se os efeitos da restricao alimentar durante a gestacao, lactacao e apos desmame na composicao quimica do cerebro de ratos em crescimento. Aos 41 dias de idade os ratos foram sacrificados e o cerebro foi analisado nos conteudos de DNA, RNA e proteina. Os grupos alimentados com dieta hiproproteica foram os mais gravemente comprometidos na avaliacao do peso cerebral e nos conteudos de DNA, RNA e proteina. Estas alteracoes foram mais acentuadas nos animais alimentados com dieta de milho em restricao alimentar