Archivos Latinoamericanos de Nutrición (Jun 2007)
Estudio comparativo entre dos fuentes alimentarias aportadoras de ácidos grasos poliinsaturados n-3 y su efecto sobre el timo y el perfil lipídico de ratas
Abstract
En este trabajo se estudia el efecto que diferentes dietas de recuperación enriquecidas en ácidos grasos poliinsaturados n-3 (AGPI n-3) producen sobre el timo y el perfil lipídico sérico. Ratas Wistar con desnutrición proteica severa al destete (grupo D) fueron divididas en tres grupos que recibieron durante 10 días dieta a base de caseína al 20% suplementada con EPA+DHA (grupo Cas), dieta al 20% de proteína preparada usando una leche en polvo parcialmente descremada enriquecida en ácidos linoleico y linolénico (grupo L) y dieta a base de caseína al 20% (grupo control C). Cas y L aportan cada una 24 mg/día de AGPI n-3 siendo la relación n-6/n-3 de 8.1/1 y 7.6/1, respectivamente. Se extrajo y pesó el timo, determinándose el recuento de timocitos; se extrajo sangre midiéndose en suero: colesterol, triglicéridos, HDL y LDL-colesterol y los ácidos: mirístico, palmítico, esteárico, oleico, linoleico, linolénico, araquidónico, EPA y DHA. La información se analizó aplicando test de Anova. El recuento de timocitos de Cas (44.48±8.20) y L (56.45±14.72) fue superior (pComparative study between two different sources of n-3 poliunsaturated fatty acids and it effect on thymus and lipid profile in rats. In the present paper we analyzed the effect caused by different recovery diets enriched with n-3 polyunsaturated fatty acids (PUFA n-3) on thymus and serum lipid pattern. Severe depleted weanling Wistar rats (D) were divided in three groups that received during 10 days a 20% casein diet supplemented with EPA+DHA (group Cas), a 20% protein milk diet prepared using a commercial reduced-fat product enriched with linolenic and linoleic acids (group L) and a 20% casein diet as control group C. Cas and L gave each other 24 mg/day of PUFA n-3 being the ratio n-6/n-3 8.1/ 1 and 7.6/1, respectively. Thymus was removed and weighted and cell number were determined; blood was recollected and Total cholesterol, triacylglycerol, HDL and LDL-cholesterol fractions and myristic, palmitic, stearic, oleic, linoleic, linolenic, araquidonic, EPA and DHA fatty acid concentrations were measured in serum. Statistical analysis was performed using Anova test. Cell number were higher (p<0.01) in Cas (44.48±8.20) and in L (56.45±14.72) when compared to group D (1.80±0.70) and group C (23.70±4.04). L presented lower values of cholesterol, HDL and LDL-cholesterol (p<0.01) and higher values of triacylglycerol (p<0.05) when compared to Cas, being EPA (p<0.05) and DHA (p<0.01) higher in Cas. Being PUFA n-3 contribution the same in Cas and L, both diets were able to reverse the thymic athropy presenting a different hipolipemic behavior due to the different sources of PUFA n-3 used in the diets
