Inés Fernandez

Nutrition disorder and immunologic parameters: study of the intestinal villi in growing rats

OBJECTIVE The aim of the present work was to study how a diet in which cereals were the only protein source would affect B and T lymphocytes and a cell population positive for thymus-expressed chemokine (TECK) in the intestinal villi of growing rats. METHODS Wistar rats were fed a 6.5% precooked maize protein diet for 18-20 d (M group). An age-matched control group received stock diet (C group). Body weight (grams) was determined, ponderal growth rate (grams per day per 100 g) was calculated, and intestines were removed and processed by Saint-Maries technique. Tissue sections were studied by indirect immunofluorescence. CD5(+) T cells and the T-cell subsets TCRalphabeta(+), TCRgammadelta(+), CD4(+), CD8alpha(+), and CD8beta(+) in the lamina propria (LP) and intraepithelium, in addition to immunoglobulin A-positive B cells in the LP were determined (n cells/30 fields were read). In addition, the presence of the TECK(+) cell population was qualitatively assessed. RESULTS The M versus C group showed statistically significant differences in body weight and ponderal growth rate. The number of immunoglobulin A-positive B cells in the LP and the CD5(+) T cells and CD4(+), CD8alpha(+), CD8beta(+), TCRalphabeta(+), and TCRgammadelta(+) T-cell subpopulations of the M group in the LP and intraepithelium of the gut villi were significantly decreased compared with the C group (P < 0.001). The M group also showed differences in the size and cellularity of the gut villi and in the distribution of TECK. CONCLUSION The results show that intake of a low concentration of a low-quality dietary protein as the only source of protein produces an important disorder in the mucosal immunity of experimental rats.

Dietas con diferentes fuentes lipídicas: su efecto en el perfil de ácidos grasos séricos de la rata

El perfil de lipidos de una dieta es importante para prevenir enfermedades cronicas y mejorar la calidad de vida de los individuos. Objetivo: estudiar el efecto de dietas con diferentes fuentes y concentraciones lipidicas sobre el perfil de acidos grasos en suero de ratas en periodo de crecimiento activo. Las dietas experimentales, contenian 15 y 40 Kcal% de lipidos aportados por: manteca (M); aceite de oliva (O); aceite de girasol alto oleico (AO) y aceite de girasol (G). El control recibio dieta normocalorica (fuente lipidica: aceite de soja). Los grupos M, O y AO presentaron un aumento en los niveles sericos del acido oleico, con disminucion de los acidos grasos esenciales (AGE) con respecto al grupo C. Estos resultados se observan independientemente del F% de la dieta. El grupo G muestra aumento de acido linoleico solo cuando el F% de la dieta fue 40. La administracion de estas dietas provoco cambios en el perfil de acidos grasos en suero en respuesta a las diferentes fuentes aportadas por las dietas, solo algunos cambios observados en el grupo G fueron tambien en respuesta al alto porcentaje de grasa

Effects of high-fat diets from different sources on serum and thymus lipid profile: study in an experimental model.

BACKGROUND A balanced diet is important to maintain an optimal health status and to prevent noncommunicable chronic diseases. The principal objective of this study was to analyze the effect of diets containing high fat levels from different sources, on serum and thymus lipid profile, in adult rats. METHODS Experimental diets contained 50% kcal of fat, provided by butter (B) or sunflower oil (S); control diet (C) was isocaloric, with 15 kcal of fat per 100 total kcal, provided by soy oil. Diets were otherwise complete in all nutrients and were administered for 40 days. RESULTS Group B had higher levels of total cholesterol and triglycerides than C; S serum lipid profile did not differ from C, despite the higher fat content. Regarding serum and thymus FA profile, B showed an increase of saturated fatty acids and lower levels of ω6 and ω3 FA, and S had lower levels of ω3 fatty acids. CONCLUSIONS The administration of high-fat diets, during 40 days to adult rats, provoked specific variations on serum and thymus fatty acids, as a consequence of differences in FA profile of their lipid sources. These results reflect the impact that eating habits have on health status. It is important to put emphasis not only on the reduction of total fat intake, but also on choosing healthy sources of fat, replacing saturated fatty acids by polyunsaturated and including oils with higher content of ω3 to keep a balanced ω6/ω3 ratio.

Effect of a quinoa (Chenopodium quinoa W) based diet on the intestinal mucosa of growing Wistar rats

.The aim of the present study was to Þnd out the effect of a variety of quinoa from Campo Tapial de Colanzuli, Iruya, Salta, withoutwashing treatment, on the intestinal mucosa of growing rats.In this study, Wistar rats ( n = 6/group) from weaning to 7 days fed a 10% protein diet with 1) unwashed quinoa (Q), 2) commercialwashed quinoa (QR), and 3) casein (C) as control group. Body weight (BW, g) and diet intake (I, g/day) were determined, and PonderalGrowth Rate (PGR, g/day/100g) was calculated. Intestines were removed, processed by Saint Marie «s technique and stained with AlcianBlue-H/E. Goblets cells/100 epithelial cells (GC) were determined in 10 intestinal villi/rat. Tissue sections were studied by indirectimmunosuorescence technique

ω3 polyunsaturated fatty acids and maize flour diets

OBJECTIVES Nutrition disorders caused by a 6.5% maize protein diet (M), unbalanced in its indispensable amino acid pattern, provokes an arrest on cellular proliferation and maturation in the thymus of growing rats. We investigated the effect of diet supplementation with different amounts of omega3 polyunsaturated fatty acid (M = 0 mg/d, M1 = 12 mg/d, M2 = 24 mg/d, respectively) on thymus, plasma lipid concentrations, and hepatic tissue. METHODS A well-nourished age-matched control group received stock diet from weaning. The animals (8 to 10 per group) received the diets for 9 d. At the end of the experimental period, they were killed, thymuses were removed, and cell number, absolute number of T cells labeled by the monoclonal antibody W3/13, plasma lipid profile (total cholesterol, triacylglycerols, high- and low-density lipoprotein cholesterols), and oxidative stress in hepatic tissue were determined. RESULTS Only M2 reached the values of the control group when cell number and absolute number of T cells were compared. No statistical differences were observed among the M, M1, M2, and control group when high- and low-density lipoprotein cholesterols and hepatic lipid peroxidation were considered. CONCLUSIONS The supplementation of a 6.5% maize protein diet with 24 mg/d of omega3 polyunsaturated fatty acid can recover the proliferation and absolute number of T cells labeled with W3/13 without affecting lipid profile and hepatic lipid peroxidation.