Submitted to: Journal of Nutrition
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/27/2001
Publication Date: 10/20/2001
Citation: Poulos, S.P., Sisk, M., Hausman, D.B., Azain, M.J., Hausman, G.J. 2001. Pre- and postnatal dietary conjugated linoleic acid alters adipose development, body weight gain and body composition in sprague-dawley rats. Journal of Nutrition. Interpretive Summary: Conjugated linoleic acid (CLA) is a dietary supplement composed of a group of positional and geometric isomers of linoleic acid that favorably influence the quality and composition of pig carcasses. Most dietary CLA studies have focused on the growing phase but very few studies have focused on the gestation or lactation period. Rats were used in this study to examine the potential influence of CLA fed to dams during gestation and lactation on fat deposition in the offspring. The expression of a major DNA binding protein that regulates fat cell gene expression was increased in fat tissue of 21 day-old offspring from dams fed CLA during gestation and lactation. Feeding CLA during gestation and lactation also decreased the number of large fat cells and increased the number of small fat cells in 21 day -old offspring. Therefore, feeding CLA during gestation and lactation may predispose the offspring to reduced fat deposition later in life.
Technical Abstract: An experiment was conducted to determine the effects of CLA during gestation and lactation on adipocyte development. Sprague-Dawley rats were fed either a control diet containing 7% soy oil or a CLA diet containing 6.5% soy oil and 0.5% CLA beginning on day 7 of gestation until day 21 of lactation. At birth, total litter weights were not different between control and CLA-fed animals. Pups from each litter were sacrificed and body cross sections (posterior end) at birth and the inguinal adipose depot at day 21 (weaning) were collected. CLA incorporation into body sections (birth) and inguinal adipose depot ( day 21) resulted in age and sex dependant changes in the fatty acid composition. At birth, there was no significant difference in lipid accretion in the inguinal depot of CLA fed litters as compared to control fed litters (p<0.05). CLA did not alter adipocyte proliferation at birth or at day 21. Western blot analysis of CCAAT/ Enhancer Binding Protein (C/EBP ) showed that fat tissue C/EBP expression in weaning male rats was not influenced by dietary CLA but was increased six fold (P<0.01) in female weaning rats . Therefore, response to CLA treatment may depend on sex and age of the animal. These results suggest CLA fed during gestation and lactation could alter fat accretion and body composition.