High fat diet differentially regulates the expression of olfactory receptors in the duodenum of obesity-prone and obesity-resistant rats.
BACKGROUND
The gastrointestinal tract is important in the regulation of food intake, nutrient sensing and nutrient absorption. Obesity-prone Osborne-Mendel (OM) rats are less sensitive to the satiating effects of a duodenal infusion of fatty acids than obesity-resistant S5B/Pl (S5B) rats, suggesting that the gastrointestinal tract differentially senses the presence of fat in these two strains. A microarray analysis was conducted to identify genes that were differentially expressed in the duodenal enterocytes of OM and S5B rats.


OBJECTIVE
The present experiment evaluated the expression of olfactory receptors in the duodenal enterocytes of OM and S5B rats. It was hypothesized that olfactory receptors present in the duodenum of OM and S5B rats would be differentially regulated by the intake of a high fat diet.


METHODS
The mRNA levels of four olfactory receptors (Olr1744, Olr50, Olr124, Olr1507) were assessed from the duodenal enterocytes of OM and S5B rats consuming a high fat diet for 14 days.


RESULTS
The duodenal mRNA levels of Olr1744, Olr124 and Olr1507 were significantly elevated in OM rats fed the high fat diet, but not S5B rats. No differences in the expression of Olr50 receptor mRNA were detected.


CONCLUSIONS
These data suggest that several olfactory receptors present in the duodenum are selectively regulated by high fat diet intake in obesity-prone OM rats. Therefore, these receptors may play a role in the sensing and regulation of dietary fat, and may be important for the individual susceptibility to obesity in these two strains.
Joint Diabetes, Endocrinology and Metabolism Program, Louisiana State University System, Louisiana State University Health Science Center-New Orleans, New Orleans, LA 70112, USA. sprime@lsuhsc.edu
Stefany D
SD
Primeaux
H Douglas
HD
Braymer
George A
GA
Bray
D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D004386:Duodenum / Q000378:metabolism*; D020895:Enterocytes / Q000378:metabolism; D005227:Fatty Acids / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D020022:Genetic Predisposition to Disease; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009765:Obesity / Q000235:genetics / Q000378:metabolism*; D040081:Protein Array Analysis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D004041:Dietary Fats; D005227:Fatty Acids; D008565:Membrane Proteins; D012333:RNA, Messenger