CD36 mRNA in the gastrointestinal tract is differentially regulated by dietary fat intake in obesity-prone and obesity-resistant rats.
BACKGROUND
The gastrointestinal tract (GI) is important for detection and transport of consumed nutrients and has been implicated in susceptibility to diet-induced obesity in various rat strains.


OBJECTIVE
The current studies investigated the regulation of CD36, a receptor which facilitates uptake of long-chain fatty acids, in the GI tract of obesity-prone Osborne-Mendel and obesity-resistant S5B rats fed a high-fat diet.


METHODS
Osborne-Mendel and S5B rats consumed a high-fat diet (HFD, 55 % kcal from fat) or a low-fat diet (10 % kcal from fat) for either 3 or 14 days. CD36 messenger RNA (mRNA) levels were measured from circumvallate papillae of the tongue and from duodenal enterocytes.


RESULTS
In Osborne-Mendel rats, consumption of HFD for 3 and 14 days led to an increase in CD36 mRNA on circumvallate papillae and in duodenal enterocytes. CD36 mRNA levels were positively correlated with body weight gain and kilocalories consumed at 3 days. In S5B rats, consumption of HFD for 3 days did not alter CD36 mRNA levels on circumvallate papillae or in the duodenum. Duodenal CD36 levels were elevated in S5B rats following 14 days of HFD consumption. CD36 mRNA levels in the duodenum were positively correlated with body weight gain and kilocalories consumed at 14 days.


CONCLUSIONS
These data support the differential sensing of nutrients by two regions of the GI tract of obesity-prone and obesity-resistant rats consuming HFD and suggest a role for CD36 in the strain-specific susceptibility to obesity.
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
D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D018955:CD36 Antigens / Q000235:genetics* / Q000378:metabolism; D059305:Diet, High-Fat; D004041:Dietary Fats / Q000494:pharmacology*; D004386:Duodenum / Q000166:cytology / Q000502:physiology*; D020895:Enterocytes / Q000502:physiology; D005227:Fatty Acids / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D009765:Obesity / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011922:Rats, Mutant Strains; D013045:Species Specificity; D013650:Taste Buds / Q000166:cytology / Q000502:physiology*
D018955:CD36 Antigens; C008132:Cd36 protein, rat; D004041:Dietary Fats; D005227:Fatty Acids; D012333:RNA, Messenger