Dietary docosahexaenoic acid-enriched phospholipids normalize urinary melatonin excretion in adult (n-3) polyunsaturated fatty acid-deficient rats.
Melatonin (MEL) plays an essential role in physiologic functions associated with darkness. We examined the effects of docosahexaenoic acid (DHA)-enriched phospholipids from pig brains (BPL) or hen eggs (EPL), as sources of DHA, on lipid FA composition of pineal membranes and daytime and nighttime concentrations of 6-sulfatoxymelatonin (aMT6) in adult male control and (n-3)-deficient rats fed BPL and EPL diets for 5 wk. In two experiments, at 3 wk of age, rats were divided into subgroups and fed semipurified diets containing either peanut oil [(n-3)-deficient group] or peanut plus rapeseed oil (control group) and two dietary formulas containing either 3.5 g/100 g diet of BPL (Experiment 1) or 5.0 g/100 g diet of EPL (Experiment 2). BPL and EPL diets provided approximately 200 mg of DHA/100 g diet. During the daytime, aMT6 concentrations were not significantly different among groups. Conversely, the (n-3)-deficient rats had significantly lower nighttime aMT6 concentrations than the control rats. BPL and EPL did not affect urinary nighttime aMT6 concentration in the control group, whereas (n-3)-deficient + BPL or EPL groups exhibited significantly higher nighttime aMT6 concentrations than the (n-3)-deficient group (76 and 110%, respectively). The level of DHA was significantly higher in the pineal glands of control rats than in (n-3)-deficient rats. In rats fed EPL and BPL, the level of DHA reached a plateau, between 10 and 11 mg/100 mg total fatty acids in control + BPL or EPL and (n-3)-deficient + BPL or EPL groups. These findings suggest that new DHA-enriched formulas may be used as an efficient alternative source of (n-3) polyunsaturated fatty acids to normalize MEL secretion.
Zaouali-Ajina
M
M
Laboratoire de Physiologie de l'Environnement, Faculté de Médecine Lyon Grange-Blanche, 69373 Lyon Cedex 08, France.
Gharib
A
A
Durand
G
G
Gazzah
N
N
Claustrat
B
B
Gharib
C
C
Sarda
N
N
D000818:Animals; D002645:Chickens; D002940:Circadian Rhythm; D004041:Dietary Fats / Q000008:administration & dosage; D004281:Docosahexaenoic Acids / Q000008:administration & dosage* / Q000494:pharmacology; D005227:Fatty Acids / Q000032:analysis*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D008297:Male; D008550:Melatonin / Q000031:analogs & derivatives* / Q000652:urine; D010743:Phospholipids / Q000008:administration & dosage* / Q000378:metabolism; D010870:Pineal Gland / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D013552:Swine
D004041:Dietary Fats; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D010743:Phospholipids; C054513:6-sulfatoxymelatonin; D004281:Docosahexaenoic Acids; D008550:Melatonin