Effects of protein quality on appetite and energy metabolism in normal weight subjects / Efeitos da qualidade proteica no apetite e metabolismo energético de indivíduos eutróficos

OBJECTIVE: The purpose of this study was to compare the effects of consumption of different protein sources on food intake and energy expenditure in normal weight subjects. SUBJECTS AND METHODS: Breakfast preparations (casein, soy protein, whey protein or control) were ingested during seven consecutive days. Appetite, food intake, and energy expenditure were assessed. RESULTS: Casein consumption led to a lower energy intake than whey protein. There was lower energy intake on day 7 than on day 1 of the casein session. Soy protein preparations resulted in higher diet induced thermogenesis (DIT) than in control preparations. The respiratory quotient (RQ) obtained in the whey protein session was lower than the control and soy protein sessions. CONCLUSION: These results suggest that the consumption of different protein types leads to distinct effects on satiety (casein), DIT (soy protein), and/or RQ (whey protein).

OBJETIVO: O objetivo deste estudo foi comparar os efeitos do consumo de diferentes fontes proteicas na ingestão alimentar e gasto energético em indivíduos eutróficos. SUJEITOS E MÉTODOS: Preparações (caseína, proteína da soja, proteína do soro de leite ou controle) foram ingeridas no desjejum, durante sete dias consecutivos. RESULTADOS: A caseína resultou em menor ingestão calórica do que o soro de leite. Houve uma menor ingestão calórica no último dia da sessão da caseína em relação ao primeiro dia. Preparações contendo proteína da soja resultaram em maior termogênese induzida pela dieta (TID) em comparação às preparações controle. O cociente respiratório (CR) obtido na sessão do soro de leite foi menor que na sessão controle e da proteína da soja. CONCLUSÃO: Esses resultados sugerem que o consumo de diferentes tipos de proteínas resulta em efeitos distintos na saciedade (caseína), TID (proteína da soja) e/ou CR (proteína do soro).

Rapid restoration of colonic goblet cells induced by a hydrolyzed diet containing probiotics in experimental malnutrition

PURPOSE: To investigate the effects of the addition of probiotic bacteria to a hydrolyzed diet on the recovery of goblet cells during renutrition in an animal model of malnutrition. METHODS: Twenty-six male Wistar rats (200-250g) were included in the study. Six were kept under normal conditions (sham group) while twenty received an aproteic diet for 15 days, and were randomized thereafter to receive a hydrolyzed diet containing (n=6; probiotic group) or not (n=6; hydrolyzed group) probiotics (10(6) cfu/g of Streptococcus thermophilus e Lactobacillus helveticus); or immediately killed (n=8; aproteic group). Histological slides containing cecal and sigmoid biopsies were used to counting the number of goblet cells and the goblet cells/colonocytes ratio. RESULTS: Malnutrition diminished the population of goblet cells in all sites. Goblet cells/colonocytes ratio of the probiotic group was significantly greater than hydrolyzed group at the ceccum (0.39 ± 0.03 vs. 0.34 ± 0.02; p=0.02). Only rats fed with probiotics showed complete restoration of the normal goblet cells/colonocytes ratio at the sigmoid (0.37 ± 0,02 vs. 0.22 ± 0,03; p<0,001). CONCLUSION: Streptococcus thermophilus and Lactobacillus helveticus added to a renutrition diet enhance the recovery of mucocal atrophy induced by malnutrition and especially induce a rapid restoration of goblet cells population in the malnourished colonic mucosa.

OBJETIVO: Investigar os efeitos da adição de probióticos em uma dieta hidrolisada na recuperação de células caliciformes durante a renutriçao em um modelo animal de desnutrição. MÉTODOS: Vinte e seis ratos Wistar (200-250g) foram incluídos no estudo. Seis foram mantidos em condições normais (grupo sham) enquanto que 20 receberam uma dieta aproteica por 15 dias, e foram randomizados para receber uma dieta hidrolisada com (n=6; grupo probiótico) ou sem (n=6; grupo hidrolisado) probióticos (10(6) cfu/g of Streptococcus thermophilus e Lactobacillus helveticus); ou foram sacrificados imediatamente (n=8; grupo aproteico). Cortes histológicos contendo biopsias do ceco e sigmoide foram examinados e o número de células caliciformas e a razão caliciformes/colonócitos foram contados. RESULTADOS: A desnutrição diminuiu o número de células caliciformes em todo o cólon. A razão células caliciformes/colonócitos do grupo probiótico foi significantemente maior que o do grupo hidrolizado no ceco (0.39 ± 0.03 vs. 0.34 ± 0.02; p=0.02). Somente os ratos alimentados com probióticos mostrou restauração completa da relação células caliciformes/colonócitos no sigmóide (0.37 ± 0,02 vs. 0.22 ± 0,03; p<0,001). CONCLUSÃO: Streptococcus thermophilus and Lactobacillus helveticus adicionados a uma dieta de renutrição melhora a recuperação da atrofia mucosa induzida pela desnutrição e especialmente induzem a uma rápida restauração da população de células caliciformes na mucosa colônica desnutrida.

Hypocholesterolemic effect of protein prepared from Phaseolus aconitifolius (Jacq.).

Hypocholesterolemic effect of protein concentrate (PC) prepared from moth bean (Phaseolus aconitifolius Jacq.) seeds relative to that of pigeon pea PC and casein were investigated in rats fed on hypercholesterolemic diet containing two per cent cholesterol. The test diets containing casein and legume PCs at 10% protein level were fed to albino rats (Wistar strain) for 45 days. Compared to casein, the two legume PCs produced significantly lower levels of liver total lipid and cholesterol levels except that pigeon pea PC produced only non-significant decrease of total cholesterols in the heart. In addition, the legume PCs produced significantly lower levels of serum triglycerides and total lipids as well as lower levels of total and low-density lipoprotein cholesterol. Moreover, only moth bean PC produced a significantly higher level of serum high-density lipoprotein cholesterol. Generally, PC of moth bean seemed to be more potent at lowering the elevated hepatic and serum lipids and cholesterol levels, which were attributed to the amino acid profile of this lesser-known legume as these indices well correlated with serum cholesterol levels.

Prevention of adrenocortical hyperactivity by dietary casein in rats exposed to forced swimming stress.

Adrenal weight, adrenal hydroxysteroid dehydrogenase activity and serum corticosterone level were significantly higher in rats fed with 5% casein diet after 7 days of swimming stress (45 min/day) as compared to their controls. All the parameters were similar to their control levels in rats receiving 20% casein diet and exposed to swimming stress. The results suggest that casein can play an important role in preventing adrenocortical hyperactivity in swimming stressed rats.

Alteraciones intestinales y disminucion del crecimiento en ratas prepuberes alimentadas con soja / Intestinal alterations and reduction of growth in prepuberal rats fed with soybean

Ratas al destete de las líneas endocriadas alpha y beta, genéticamente diferentes, fueron alimentadas con una mezcla de soja y cereales formulada para consumo humano disponible en el comercio, (AN). Se usó como testigo un balanceado comercial (AC). Se evaluaron el crecimiento, variables nutricionales y la morfohistoletría intestinal. El aumento de peso vivo y la biomasa final fueron mayores con AC para ambas líneas. La eficiencia de conversión de alimento en biomasa de AN respecto de AC fue mayor inicialmente pero menor al final, especialmente en beta. Los contenidos fecales de nitrógeno y grasa fueron significativamente mayores con AN para ambas líneas. La digestibilidad aparente de nitrógeno (N), definida como la diferencia entre el N ingerido y el N excretado en heces respecto del N ingerido en la línea alpha fue AC < AN (p< 0.01) y AC> AN en la línea beta (p<0.01). El peso de intestino delgado y el espesor de su mucosa fueron AC > AN en ambas líneas. La dieta AN disminuyó significativamente el número de células caliciformes vellositarias (p<0.005) en las dos líneas de ratas. El peso del ciego en la línea beta fue AC > AN (p<0.01). Los resultados alertan respecto del consumo indiscriminado de productos en base a soja sin tratamientos addecuados de inhibición de antinutrientes, particularmente riesgosos para animales en crecimiento.

Efeitos da dieta proteica na cicatrizaçäo de fraturas distais de fêmur imobilizadas com pinos intramedulares em cäo / Diet's effects on bone healing of femur distal fracture imobilized with internal pins in dogs

No presente experimento vinte cäes sem raça definida, pesando em média 6 Kg, com idade variando entre 4 e 12 anos, vindos do Biotério Central da Universidade Federal de Santa Maria (UFSM), foram distribuidos em dois grupos com 10 animais, cada grupo dividido em dois subgrupos com 5 cäes, denominados IA, IB, 2A e 2B. Os animais do grupo 1 receberam tratamento por 90 dias, e os do grupo 2 por 60 dias após a cirurgia. O subgrupo A correspondem a tratamento com raçäo crescimento contendo 27 por cento de proteina bruta e o subgrupo B raçäo manutençäo com 21 por cento de proteina bruta. Todos os cäes sofreram fratura distal de fêmur, experimental, reduzidas com dois pinos intramedulares, introduzidos através da superfície articular da trócrea. Os cäes ficaram confinados em canis individuais até a remoçäo dos pontos e em canis comuns para no máximo 5 cäes até o término do experimento. Foi feita avaliaçäo clínica, radiográfica e histológica da evoluçäo da cicatrizaçäo óssea a qual demonstrou que o tratamento com raçäo com maior teor de proteina proporcionou melhor regeneraçäo e que a técnica de osteossíntese utilizada manteve estabilidade na linha de fratura

Effect of protein supplemented cassava diet in rats.

The effect of feeding rats with cassava diet (tapioca) has been investigated with respect to the activities of superoxide dismutase, catalase and levels of TBARS. By varying the levels of protein in the diet and cyanide content of cassava, the possible role of a high protein diet in the prevention of oxidant stress has been shown. Rhodanese which detoxifes cyanide is also found to be inhibited in rats fed low protein diet while the inhibition was only marginal in the high protein fed groups.

Effect of dietary protein manipulation on translocation of protein kinase C activity in various tissues of rats.

Ingestion of protein deficient diet is known to decrease the enzyme load, particularly drug metabolising enzymes in liver. It also leads to decrease in polyphosphoinositide pool in brain and kidney. Therefore, changes in protein kinase C activity and its translocation were speculated and studied in brain, lung, heart, spleen, liver and kidney of rats maintained on three different diets, viz. casein (20% protein) deficient (4% protein, rice flour as protein source) and supplemented (deficient diet supplemented with L-lysine and DL-threonine), for 28 days. A significant alteration in total protein kinase C activity and/or its translocation was observed in these tissues in the deficient group in comparison to casein group. Supplementation of diet with L-lysine and DL-threonine could partially reverse the affect. These changes in protein kinase C activity and its translocation indicate alteration in the mechanism of signalling system in dietary protein deficiency and hence an altered response of tissues to the external stimuli in dietary protein deficiency.

Influence of dietary protein on DDT-induced immune responsiveness in rats.

The influence of protein deficiency was evaluated on immune responsiveness after subchronic DDT exposure in albino rats. Rats were given 20%, 12% and 3% protein diets and exposed to DDT (20, 50 or 100 ppm) for 4 weeks. DDT (50 and 100 ppm) induced humoral and cellular immune suppression only in rats fed on 3% protein diet. There was (a) an increase in the albumin/globulin ratio, (b) suppression in IgM and IgG levels, and (c) attenuation in the tetanus toxoid-induced antibody responses. Further, in rats immunized with tetanus toxoid, the leucocyte and macrophage migration inhibition were also attenuated. Moreover, these animals maintained on 3% protein diet showed depression in humoral and cellular immune responses to antigen in a dose-dependent pattern after exposure to DDT at dose levels which were not immunosuppressive for rats on 12% or 20% protein diet. These results suggest that dietary protein content may predispose to the immunotoxic effects of DDT exposure, and also be a crucial determinant in DDT detoxification.

Effects of dietary protein, angiotensin I converting enzyme inhibition and mesangial overload on the progression of adriamycin-induced nephropathy

Adriamycin, a commonly used antineoplastic antibiotic, induces glomerular lesions in rats, resulting in persistent proteinuria and glomerulosclerosis. We studied the effects of dietary protein and of an angiotensin I converting enzyme inhibitor on the progression of this nephropathy and the evolution of the histological lesions, as well as mesangial macromolecule flow. Adriamycin nephropathy was induced by injecting a singl iv dose of adriamycin (3 mg/kg body weight) into the tail vein of male wistar rats (weight, 180-200 g). In Experiment I animals with adriamycin-induced nephropathy were fed diets containing 6 percent (Low-Protein Diet Group = LPDG), 20 percent (Normal-Protein Diet Group = NPDG) and 40 percent (High-Protein Diet Group = HPDG) protein and were observed for 30 weeks. In Experiment II the rats with adriamycin nephropathy were divide into 2 groups: ADR, that received adriamycin alone, and ADR-ENA, that received adriamycin plus enalapril, an angiotensin I converting enzyme inhibitor. The animals were sacrificed after a 24-week observation period. Six hours before sacrifice the animals were injected with 131I-ferritin and the amount of 131I-ferritin in the glomeruli was measured. In Experiment III, renal histology was performed 4, 8 and 16 weeks after adriamycin injection. At the end of Experiment I the tubulointerstitial lesion index was 2 for LPDG, 8 for NPDG, and 7.5 for HPDG (P,0.05); the frequency of glomerulosclerosis was 19 + or - 6.1 percent in LPDG, 42.6 + or - 6 percent in NPDG, and 54 + or - 9 percent in HPDG (P,0.05); and proteinuria was 61.1 + or - 25 mg/24 h in LPDG, 218.7 + or - 27.5 mg/24 h in NPDG, and 324.5 + or - 64.8 mg/24 h in HPDG (P,0.05). In Experiment II, at sacrifice, 24-h proteinuria was 189 + or - 16.1 mg in ADR, and 216 + or - 26.1 mg in ADR-ENA (P.0.05); the tubulointerstitial lesion index was 5 for ADR, and 5 for ADR-ENA (P.0.05); the frequency of glomerulosclerosis was 40 + or - 5.2 percent in ADR and 44 + or - 6 percent in ADR-ENA (P.0.05); the amount of 131I-ferritin in the mesangium was 214.26 + or - 22.71 cpm/mg protein in ADR and 253.77 + or - 69.72 cpm/mg protein in ADR-ENA (P.0.05). In Experiment III, sequential histological analysis revealed an acute tubulointerstitial cellular infiltrate at week 4, whigh was decreased at week 8. Tubular casts and dilatation were first seen at week 8 and increased at week 16 when few glomerular lesions were found. The results suggest that the tubulointerstitial lesions may play a role in the development of glomerulosclerosis in adriamycin-induced nephropathy

Effects of protein deficiency and natural intestinal infection with Giardia lamblia on jejunal intraepithelial lymphocytes in rats of different ages

1. The interaction between experimental protein deprivation and natural intestinal infection by Giardia lamblia was studied in terms of its effects on the intraepithelial lymphocyte (IEL) population and morphology of the jejunal mucosa of rats of different ages. 2. Young, adult and old male Wistar rats received a protein-deficient diet (2 casein) or a control diet (20 casein) for 42 days. Mucosal height and the number of lymphocytes located among 500 consecutive epithelial cells (EC) along the villi or crossing the basement membrane were determined in PAS-stained jejunal fragments. 3. The number of IEL increased progressively with animal age, from 14 to 25 per 100 epithelial cells, with significant differences between age ranges. However, the number of IEL did not differ between control and protein-deficient rats in any of the age groups. The proportion of lymphocytes crossing the basement membrane was approximately two-fold greater in young (2.8/100 EC) and adult (5.8/100 EC) protein-deficient animals than in their respective controls (1.6 and 2.8/100 EC). The intensity of parasite colonization was moderate, from 3 to 5/100 EC and did not differ between groups. The pattern of morphologic changes of jejunal mucosa in protozoal infection did not differ between control and protein-deficient animals in any of the three age groups. 4. We conclude that intestinal infection with Giardia lamblia probably stimulated the local immune response, masking the reduction of the IEL population induced by protein deficiency. The increase in lymphocyte numbers with age may be related to prolonged antigenic stimulation promoted by infection.

Comparison of the effects of lab chow and casein diets based on body and brain development of rats

1. In order to study the effects of protein quantity and quality on development, Wistar rats were submitted to four different diets during lactation and post-lactation periods. Three isocaloric diets were utilized with 6 per cent (M), 16 per cent (W16) and 20 per cent (W20) of protein (casein), and the fourth diet (C) consisted of a commercial lab chow containing 22 per cent protein. 2. During the lactation and post-lactation periods the body weights of dams and pups were recorded weekly. On the 49th day of age (21 days of suckling and 28 days of ad libitum chow), all animals were sacrificed and the brains removed and weighed. 3. Dams from all groups increased food intake during the lactation period, but dams of the M group consumed a lower amount of diet as compared with other groups. Only the body weight of M dams was affected by diet during the lactation period, but the body weight of pups from the M and C groups was lower than in the other two groups. At 49 days of age C and M pups showed a significantly lower brain weight compared with W16 and W20 pups. 4. Thus, a commercial lab chow diet does not promote normal body and brain development as compared with balanced diets containing 16 or 20 per cent protein. These results emphasize the need for further studies in order to evaluate other biological and behavioral parameters that might be altered by a lab chow diet

Effect of macrocomponents of food on the pharmacokinetics of a long acting preparation of anhydrous theophylline.

In a single dose crossover study, the effect of macrocomponents of food on the pharmacokinetics of a long acting preparation of anhydrous theophylline was investigated. Compared to fasting subjects, carbohydrate and fat rich diet caused an enhancement of absorption half life and a lower Cmax with a delayed tmax and elimination of the bronchodilator. Protein coadministration decreased AUCO-OC of the drug without significantly altering its absorption or elimination kinetics.

Nutrient interaction in relation to glycaemic and insulinaemic response.

Although it is known that protein, fat and fibre reduce the postprandial glycaemia following an oral carbohydrate load, the nature and extent of interaction of different nutrients with one another in this respect is not well understood. The present study was designed to explore systematically the glycaemic and insulinaemic response to glucose (G) alone, or in combination with one or more of the following: casein (CS), maize oil (MO), cellulose (CL) and pectin (P). Besides 100 g G, eleven isoenergetic and six isocarbohydrate meals were studied on healthy adult males using an incomplete block design. Addition of other nutrients to G led to a lowering of the glycaemic response. The lowest glycaemic responses were seen in case of meals containing the largest number of nutrients. P was more effective in reducing postprandial glycaemia than CL. As in case of glycaemic response, low insulinaemic responses were also associated with P-containing meals, and meals containing the largest number of nutrients. But unlike in case of glycaemic response, there was a tendency for elevation of the insulinaemic response in case of CL-containing meals. The degree of attenuation of glycaemic response observed with meals containing several nutrients was roughly predictable on the basis of the attenuation observed with meals in which only one nutrient had been added at a time to G. But the glycaemic response of natural foods is unlikely to be predictable on the basis of their nutrient composition because of the overriding influence of several other factors such as physical form, cooking, processing, storage and antinutrient content of the food.

Effects of protein restriction on functional properties of rat peritoneal macrophages.

Rats were maintained on 20% and 4% protein diets for 3 weeks. The functional properties of thioglycollate (TG) elicited macrophages from these groups were compared with the non elicited resident cells from the protein fed group. Elicitation of macrophages in response to TG was low in the protein deficient group. These cells also exhibited low adherence in overnight cultures compared to those isolated from the protein fed group; however their viability and total protein content remained unaltered. Normal resident and TG elicited cells from 4% protein fed group exhibited an initial lag period in H2O2 production in response to zymosan stimulation. The lag period could be correlated to the high endogeneous catalase activity in these cells. Incubation with zymosan resulted in rapid decline in catalase levels, facilitating evolution of H2O2. On prolonged incubation, the elicited cells from the protein fasted rats evolved about 87% H2O2 compared to the protein fed samples. In the absence of zymosan all the samples possessed comparable NADPH oxidase activity. Zymosan induced activation of this enzyme was higher in TG cells from the protein fed groups, compared to the protein fasted and the resident samples. The cellular enzyme activity, however was not altered in the TG cells of both the groups though it declined rapidly in the corresponding resident cells. Significant reduction (congruent to 50%) in both serum iron and transferrin in the low protein fed samples did not correspondingly affect the oxidative burst process. However the engulfment of yeast cells was greatly impaired due to protein restriction. Adherence and phagocytic properties of macrophages are regulated by the activity of their membrane constituents.(ABSTRACT TRUNCATED AT 250 WORDS)

Additive effects of dietary protein and energy deficiencies on diaphysis and bone tissue of rat femurs as determined by bending tests

El estudio presente fue diseñado con el objeto de estudiar los efectos de dietas moderadamente restringidas en proteínas o en calorías derivadas de glúcidios sobre parámetros morfométricos (propiedades geométricas) y comportamento biomecánico de diáfisis (propiedades estructurales) y de tejido óseo cortical (propiedades estructurales y de tejido óseo cortical (propiedades materiales) de fémures de rata mediante ensayos de flexión. Ratas macho de 30 días de edad fueron divididas en cuatro grupos, a saber: NN = proteína normal y energía normal, NPLE = proteína normal, energía reducida, LP = proteína reducida, energía normal y LPLE = proteína reducida, energía reducida. Cada grupo fue alimentado con su correspondiente dieta durante un lapso de 20 días. Tanto el peso corporal como la longitud femoral, índices de crecimiento corporal generalizado y de crecimiento longitudinal del esqueleto, respectivamente, fueron mayores en el grupo NN y menores en el LPLE que en los grupos NPLE y LP. Las variables geométricas y estracturales (con excepción de la relación pared/lumen) mostraron cambios paralelos a los observados en el peso corporal, mientras que las propiedades materiales mostraron un comportamiento independiente y menos marcado. Por lo tanto los niveles ensayados de restricción de nutrientes plásticos y/o energéticos parecieran alterar la biomecánica ósea en forma proporcional a la forma en que afectan el crecimiento corporal y óseo

Plant lectins, chemical and biological aspects

Lectins, carbohydrate-binding proteins of non-immune origin, that agglutinate cells or precipitate polysaccharides and glycoconjugates, are well distributed in nature, mainly in the Plant Kingdom. The great majority of the plante lectins are present in seed cotyledons where they are found in the cytoplasm or int he protein bodies, although they have also been found in roots, stems and leaves. Due to their peculiar properties, the lectins are used as a tool both for analytical and preparative purposes in biochemistry, cellular biology, immunology and related areas. In agriculture and medicine the use of lectins greatly improved in the last few years. The lextins, with few exceptions, are glycoproteins, need divalent cations to display full activity and are, in general, oligomers with variable molecular weight. Although the studies on lectins have completed a century, their role in nature is yet ynknown . Several hypotheses on their physiological functions have been suggested. Thus, lectins could play important roles in defense against pathogens, plant-microorganism symbiosis, cell organization, embryo morphogenesis, phagocytosis, cell wall elongation, pollen recognition and as reserve proteins. A brief review on the general properties and roles of the lectins is given.

Maternal nutrition and development of intestinal functions: II--Effect of feeding high protein and high fat diets to lactating rats.

Effects of feeding high-protein (HP) and high-fat (HF) diets to lactating rats have been studied on the development of microvillus membrane enzymes and glycosylation in suckling rats. The activities of sucrase and lactase were significantly (P less than 0.01) decreased in the pups reared on HP fed dams. Alkaline phosphatase (AP), leucine aminopeptidase (LAP) and gamma-glutamyl-transpeptidase (gamma-GTP) activities were essentially similar in HP and pair-fed groups. Pups reared on dams fed HF-diet, revealed nearly a 20% increase in disaccharidase levels and a significant (P less than 0.05) decrease in AP activity compared to the pair-fed controls. The activities of LAP and GTP were unaffected under these conditions. Sialic acid content was unaltered, however, fucose level of the membranes was significantly reduced in pups nursed by mothers fed HP-(P less than 0.05) or HF-(P less than 0.01) diet. The binding of 125I-labelled wheat germ agglutinin and Ulex europeus agglutinin was in agreement to the data on sialic acid and fucose contents of the membranes. The binding of peanut agglutinin to microvillus membranes was enhanced by 31% and 21% in HP and HF groups, respectively. These findings suggest that the quality of maternal nutrition affects the enzymes and glycosylation of brush-borders in developing rat intestine.