Short-term dietary conjugated linoleic acid supplementation does not enhance the recovery of immunodepleted dexamethasone-treated rats.
BACKGROUND
Conjugated linoleic acid (CLA) has been reported to decrease fat deposition, and increase lean body mass. This has been broadly inferred to mean that CLA alters protein turnover. However, data to test the effects of CLA on protein turnover are lacking. An enhancement in immune responses by CLA has also been demonstrated.


OBJECTIVE
The objective of this study was to determine the potential for dietary CLA and protein intervention to improve nutritional and functional recovery in an animal model of catabolic stress and immunodepletion.


METHODS
Diets varying in their protein levels in the presence or absence of CLA were tested for their effects on the recovery of glucocorticoid (intraperitoneal injection of dexamethasone, 120 mg/kg) treated rats. Following steroid injection, rats were fed 4 dietary treatments for 4 d. The diets contained 10 or 20 g/100 g protein with or without 0.5 g/100 g CLA.


RESULTS
Dexamethasone treatment resulted in a decreased food intake and loss of weight, independent of dietary treatment. A higher number of blood monocytes occurred in rats fed the high CLA diets. The protein fractional synthesis rate in spleens of rats fed the diets containing either high proteins or CLA were higher compared to those fed diets with low protein content or without CLA, respectively. CLA, consumed post-dexamethasone treatment, did not improve protein turnover in the other tissues studied, including gut mucosa, liver, muscle and thymus.


CONCLUSIONS
The present study was performed to determine the effect of CLA in acute conditions, as opposed to a preventive approach, on the recovery from a catabolic stress with immunodepletion. Overall, no effect of short-term feeding CLA on the recovery from dexamethasone-mediated immunodepletion was observed.
Turini
Marco E
ME
Dept. of Nutrition, Nestlé Research Center, Nestec Ltd., P.O. Box 44, 1000 Lausanne 26, Switzerland. marco.turini@rdls.nestle.com
Boza
Julio J
JJ
Gueissaz
Nathalie
N
Moënnoz
Denis
D
Montigon
Frank
F
Vuichoud
Jacques
J
Gremaud
Gérard
G
Pouteau
Etienne
E
Piguet
Christelle
C
Perrin
Irène
I
Verguet
Clotilde
C
Finot
Paul-André
PA
German
Bruce
B
D000818:Animals; D001772:Blood Cell Count; D003907:Dexamethasone / Q000494:pharmacology*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000378:metabolism; D019587:Dietary Supplements; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005938:Glucocorticoids / Q000494:pharmacology*; D005978:Glutathione / Q000032:analysis; D007111:Immunity, Cellular / Q000187:drug effects*; D007274:Injections, Intraperitoneal / Q000662:veterinary; D008041:Linoleic Acids / Q000008:administration & dosage* / Q000494:pharmacology; D008099:Liver / Q000737:chemistry / Q000187:drug effects; D008213:Lymphocyte Activation / Q000187:drug effects; D018482:Muscle, Skeletal / Q000737:chemistry / Q000187:drug effects; D009929:Organ Size / Q000187:drug effects; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013950:Thymus Gland / Q000187:drug effects
D004044:Dietary Proteins; D005938:Glucocorticoids; D008041:Linoleic Acids; D003907:Dexamethasone; D005978:Glutathione