RESUMO
Weanling rats from the inbred lines alpha and beta were fed with a soybean-cereal mixture used for human consumption (AN). A group fed with laboratory rat chow was used as reference (AC). Growth and other nutritional parameters as well as intestinal morphohystometry were evaluated from 22 to 44 days of age. Growth rate and final weight were greater with AC in both lines of rats. The greater initial food conversion efficiency of AN diet, compared to AC, decreased rapidly with the progression of age, particularly in the beta strain. Nitrogen (N) and lipid fecal contents were significantly larger for AN in both lines. Apparent nitrogen digestibility, expressed as the difference between N intake and fecal N with respect to N intake was AC < AN (p < 0.01) for line alpha and AC > AN (p < 0.01) for line beta. The weight and the mucosal total width of the small intestine were AC > AN in both lines. AN produced a significant decrease of villi goblet cells in both strains (p < 0.005). Cecum weight was AC > AN (p < 0.01) for the beta strain. These results alert about uncontrolled consumption of soybean products without adequate inhibition of antinutritional factors, a potential risk for growing animal populations.
Assuntos
Proteínas Alimentares/farmacologia , Crescimento/efeitos dos fármacos , Intestinos/efeitos dos fármacos , Proteínas de Soja/farmacologia , Animais , Dieta , Digestão/fisiologia , Feminino , Manipulação de Alimentos/normas , Mucosa Intestinal/metabolismo , Masculino , Valor Nutritivo , Pâncreas/anatomia & histologia , Ratos , DesmameRESUMO
Weanling rats from the inbred lines alpha and beta were fed with a soybean-cereal mixture used for human consumption (AN). A group fed with laboratory rat chow was used as reference (AC). Growth and other nutritional parameters as well as intestinal morphohystometry were evaluated from 22 to 44 days of age. Growth rate and final weight were greater with AC in both lines of rats. The greater initial food conversion efficiency of AN diet, compared to AC, decreased rapidly with the progression of age, particularly in the beta strain. Nitrogen (N) and lipid fecal contents were significantly larger for AN in both lines. Apparent nitrogen digestibility, expressed as the difference between N intake and fecal N with respect to N intake was AC < AN (p < 0.01) for line alpha and AC > AN (p < 0.01) for line beta. The weight and the mucosal total width of the small intestine were AC > AN in both lines. AN produced a significant decrease of villi goblet cells in both strains (p < 0.005). Cecum weight was AC > AN (p < 0.01) for the beta strain. These results alert about uncontrolled consumption of soybean products without adequate inhibition of antinutritional factors, a potential risk for growing animal populations.
RESUMO
Indirect evidence of energy balance in laboratory rats is provided through the study of diurnal body weight variations in two inbred lines: obese beta and nonobese alpha, from birth to 200-300 days of age, with different feeding patterns from 25 to 75 days of age. Nocturnal weight gain (NWG) was the gain recorded after the dark phase, in direct relation to the acquisition of exogenous calories in excess of the current metabolic expenditure at nighttime. Daytime weight variation was either weight gain during lactation (DWG) or weight loss from weaning onwards (DWL), recorded after the light phase. DWL is in direct relation to daytime energy output, when metabolic expenditure exceeds the low rate of acquisition of exogenous calories. The correlation between averaged individual DWL and NWG absolute values was highly significant at every age studied. An increase in absolute DWL values with age was observed and at adulthood DWL was compensated for equivalent NWG. This increasing energy output with age during daytime, is most likely related to the maintenance of increasing biomass and consequently, to progressive reduced growth energy availability. The existence of energy homeostasis and ponderostat with set points genetically prescribed in adults, is suggested. Significant differences between lines found before adulthood give indirect evidence of higher fat accretion in the obese line in those periods of intense growth, known as the active phase of obesity.
Assuntos
Envelhecimento/fisiologia , Peso ao Nascer/fisiologia , Peso Corporal/fisiologia , Metabolismo Energético , Obesidade/genética , Animais , Animais Recém-Nascidos , Ritmo Circadiano , Modelos Animais de Doenças , Ingestão de Alimentos/fisiologia , Feminino , Crescimento/fisiologia , Lactação/fisiologia , Masculino , Ratos , Ratos Mutantes , Aumento de Peso/fisiologiaRESUMO
Legume seeds and fibre rich plant foods usually improve aspects of human diabetes control as they are potential sources of "delayed release" carbohydrates. A regional bakery mixture of soybean and cereals, interesting for its palatability and high content in non starch polysaccharides was chemically and nutritionally evaluated. Comparisons were made with the usual commercial laboratory chow and with a cafeteria mixture. Each one of the three diets was offered ad libitum to adult rats of line IIMb/Fm beta (beta), affected by obesity, hypertriglyceridemia and glucose intolerance or diabetes. Treatments lasted three months and were performed on two groups of male rats: (a) From 100 days old growing significantly. (b) From 200 days old. Meals had similar carbohydrate and calorie contents but acid followed by enzymatica hydrolysis was required to free monosaccharides from the soybean mixture. Cafeteria mixture lacked in fibre, was rich in saturated fats and sodium, and it caused hyperphagia. Each group of rats showed similar food intakes in both ages although weight gain was significantly higher in the younger animals. In the latter, values of glycemic response showed no difference between diets. Cafeteria mixture caused significant hyperglycemia to the elder rats, while the soybean bakery mixture produced a remarkably lower glycemic response; in one case it was even lower than the one produced by the commercial chow. Differential response showed more clearly with age. The results of the feces analysis demonstrated an increased proportion of fecal water for the bakery mixture group, probably due to the amount of undigestible fibre, inducing beneficial effects on large bowel functionality.
Assuntos
Diabetes Mellitus/prevenção & controle , Grão Comestível/metabolismo , Glycine max/metabolismo , Necessidades Nutricionais , Adulto , Fatores Etários , Animais , Diabetes Mellitus/dietoterapia , Diabetes Mellitus Experimental/dietoterapia , Modelos Animais de Doenças , Humanos , Masculino , RatosRESUMO
The female reproductive profile of a fertile genetically obese line of rats, named beta, is characterized. Hypophysis, ovaries, oviducts, and uteri weights do not differ from those of nonobese controls. Histological features in ovary, uterus, and vagina in beta line and alpha controls are similar, in agreement with classical descriptions in the subject. Vaginal opening, number of estrus, number of corpora lutea at ovulation time, and pregnancy patterns (i.e., ovary weight, number of corpora lutea, sites of implantation, and living fetuses, as well as productivity, fertility, litter size, and preweaning mortality) show no significant differences between obese and nonobese animals. From a reproductive standpoint, obese beta line would behave as nonobese. Up to now beta would represent the only fertile genetically obese line of rats, appearing as a profitable biological model to widen and deepen reproductive analysis on obesity.
Assuntos
Obesidade/fisiopatologia , Reprodução , Animais , Corpo Lúteo/citologia , Estro , Feminino , Fertilidade , Morte Fetal , Tamanho da Ninhada de Vivíparos , Masculino , Obesidade/genética , Tamanho do Órgão , Ovário/anatomia & histologia , Ovulação , Gravidez , Complicações na Gravidez/fisiopatologia , Ratos , Ratos Endogâmicos , Vagina/anatomia & histologiaRESUMO
A genetically mild obesity syndrome of pubertal onset in a highly inbred line of rats differentiated as beta (beta) has been described. It was discovered in both sexes fed a stock diet for rodents. Hyperphagia was not noticeable. Total fat content reached 31 percent of total body weight in mature males. Obesity was associated with normal plasma cholesterol values and hypertriglyceridemia. Fasting blood sugar levels at maturity were within the normal range for rats, but significantly higher than in lean alpha (alpha) controls. This syndrome developed into a mild glucose intolerance and glucosuria in older obese rats.