Various dietary fats differentially change the gene expression of neuropeptides involved in body weight regulation in rats.
Various high-fat diets are obesogenic but not to the same extent. The aim of the present study was to investigate the effects of saturated fat n-6 and n-3 polyunsaturated fatty acids (PUFAs) on the central neuropeptidergic system in adult rats. Using reverse transcriptase-polymerase chain reaction and in situ hybridisation, we evaluated the net effect of feeding in these fats, comparing the effects of a high- to low-fat diet, and the diversity of the effects of these fats in the same amount within the diet. We also determined plasma lipids, glucose, insulin and leptin concentrations. Six-week feeding with high-saturated fat evoked hyperpahagia and the largest weight gain compared to both high-PUFA diets. Rats fed high-saturated fat were found to have decreased neuropeptide Y (NPY) mRNA expression in the arcuate nucleus (ARC) and the compact zone of the dorsomedial nucleus (DMHc), unchanged pro-opiomelanocortin (POMC), galanin-like peptide (GALP) mRNA expression in the ARC, as well as melanin-concentrating hormone (MCH) and prepro-orexin (preORX) mRNA expression in the lateral hypothalamus, compared to low-saturated fed rats. By contrast, feeding with both high-PUFA diets increased POMC and GALP mRNA expression in the ARC compared to the corresponding low-fat diet and the high-saturated fat diet. Furthermore, feeding with both low-PUFA diets reduced NPY mRNA expression compared to the low-saturated fat diet exclusively in the DMHc. Uniquely, the high n-3 PUFA feeding halved MCH and preORX mRNA expression in the lateral hypothalamus compared to the other high-fat and low n-3 PUFA diets. In rats fed three high-fat diets, plasma insulin and leptin concentrations were significantly increased and the type of fat had no effect on these hormone levels. Rats fed high-saturated fat had both hyperglycaemia and hypertriacylglycerolemia and rats fed high n-3 PUFA only had hyperglycaemia. The present study demonstrates that various forms of dietary fat differentially change the expression of neuropeptide genes involved in energy homeostasis.
Dziedzic
B
B
Department of Cell-to-Cell Communication, Medical University of Lodz, Lodz, Poland.
Szemraj
J
J
Bartkowiak
J
J
Walczewska
A
A
D000818:Animals; D001069:Appetite Regulation / Q000502:physiology; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000502:physiology*; D004041:Dietary Fats / Q000145:classification / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000502:physiology*; D043371:Fatty Acids, Omega-6 / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology; D044089:Galanin-Like Peptide / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D007028:Hypothalamic Hormones / Q000235:genetics / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D007328:Insulin / Q000097:blood / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D020738:Leptin / Q000097:blood / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D008543:Melanins / Q000235:genetics / Q000378:metabolism; D009478:Neuropeptide Y / Q000235:genetics / Q000378:metabolism; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism*; D000068797:Orexins; D010907:Pituitary Hormones / Q000235:genetics / Q000378:metabolism; D011333:Pro-Opiomelanocortin / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric
D001786:Blood Glucose; D004041:Dietary Fats; D005227:Fatty Acids; D015525:Fatty Acids, Omega-3; D043371:Fatty Acids, Omega-6; D044089:Galanin-Like Peptide; D007028:Hypothalamic Hormones; D007328:Insulin; D047908:Intracellular Signaling Peptides and Proteins; D020738:Leptin; D008055:Lipids; D008543:Melanins; D009478:Neuropeptide Y; D009479:Neuropeptides; D000068797:Orexins; D010907:Pituitary Hormones; D012333:RNA, Messenger; D011333:Pro-Opiomelanocortin; C019463:melanin-concentrating hormone