Cellular and molecular aspects of fat metabolism in the small intestine

Association between the FABP2 Ala54Thr and CRP+1059C/G polymorphisms and small dense LDL level in patients with atherosclerosis: a case-control study

BACKGROUND

The polymorphisms of fatty acid-binding protein 2 (FABP2) and C-reactive protein (CRP) might act as genetic risk factors for atherosclerosis. The study aimed to investigate the relationship between FABP2 Ala54Thr and CRP+1059C/G polymorphisms and atherosclerosis as well as the association of Small dense-LDL (sd-LDL).

METHODS

A total of 255 subjects (125 controls and 130 patients) were included. The FABP2 and CRP polymorphisms were determined by PCR-RFLP and AS-PCR methods, respectively. Sd-LDL was measured based on Hirano et al method.

RESULTS

There were no significant distinctions between the patient and control groups concerning FABP2 and CRP polymorphisms (p > .05). No significant relationship was observed between studied polymorphisms and sd-LDL level in the patient group (p > .05). However, patients group had higher level of sd-LDL compared to controls (p < .05).

CONCLUSION

FABP2 Ala54Thr and CRP+1059G/C polymorphisms were not associated with atherosclerosis and sd-LDL level. However, the increased sd-LDL level was known as a risk factor for atherosclerosis.

Upregulated absorption of dietary palmitic acids with changes in intestinal transporters in non-alcoholic steatohepatitis (NASH)

BACKGROUND

Palmitic acid is an important risk factor for the pathogenesis of non-alcoholic steatohepatitis (NASH), but changes in palmitic acid intestinal absorption in NASH are unclear. The aim of this study was to clarify changes in palmitic acid intestinal absorption and their association with the pathogenesis of NASH.

METHODS

A total of 106 participants were recruited to the study, of whom 33 were control subjects (control group), 32 were patients with NASH Brunt stage 1-2 [early NASH (e-NASH)], and 41 were patients with NASH Brunt stage 3-4 [advanced NASH (a-NASH)]. ¹³C-labeled palmitate was administered directly into the duodenum of all participants by gastrointestinal endoscopy. Breath ¹³CO₂ levels were measured to quantify palmitic acid absorption, and serum Apolipoprotein B-48 (ApoB-48) concentrations were measured after a test meal to quantify absorbed chylomicrons. Expressions of fatty acid (FA) transporters were also examined. The associations of breath ¹³CO₂ levels with hepatic steatosis, fibrosis and insulin resistance was evaluated using laboratory data, elastography results and liver histology findings.

RESULTS

Overall, ¹³CO₂ excretion was significantly higher in e-NASH patients than in the control subjects and a-NASH patients (P < 0.01). e-NASH patients had higher serum ApoB-48 levels, indicating increased palmitic acid transport via chylomicrons in these patients. Jejunal mRNA and protein expressions of microsomal triglyceride transfer protein and cluster of differentiation 36 were also increased in both NASH patient groups. The ¹³CO₂ excretion of e-NASH patients was significantly correlated with the degree of hepatic steatosis, fibrosis and insulin resistance (P = 0.005, P < 0.001, P = 0.019, respectively).

CONCLUSIONS

Significantly upregulated palmitic acid absorption by activation of its transporters was evident in patients with NASH, and clinical progression of NASH was related to palmitic acid absorption. These dietary changes are associated with the onset and progression of NASH.

Rapid alternative absorption of dietary long-chain fatty acids with upregulation of intestinal glycosylated CD36 in liver cirrhosis

BACKGROUND

Dietary long-chain fatty acid (LCFA) intake is an important risk factor for hepatic inflammation and hepatocarcinogenesis. An alternate route of dietary LCFA absorption has been suggested in patients with liver cirrhosis (LC).

OBJECTIVE

We aimed to determine this alternate route and to identify its mechanism.

DESIGN

Twenty healthy control subjects and 47 patients with LC-n = 23 with portal hypertension [PH(+)LC] and 24 without portal hypertension [PH(-)LC)]-were enrolled. [¹³C]Palmitate (an LCFA) and octanoate (a medium-chain fatty acid [MCFA]) were administered by using gastrointestinal endoscopy. Breath ¹³CO₂ was measured to quantify metabolized fatty acids. We also examined intestinal specimens of patients in these groups.

RESULTS

A more rapid increase in metabolized palmitate, which showed a pattern similar to that of octanoate metabolism, was observed in patients with LC than in healthy control subjects. The increase in the PH(-)LC group was higher than that in the PH(+)LC group. However, the concentration of metabolized palmitate increased with treatment of the PH(+)LC group with a portal-systemic shunt. Morphologic changes such as expanded lymph and blood vessels were present, and glycosylated CD36 increased in the jejunum of the PH(+)LC group. This group had high serum concentrations of glucagon-like peptide-2. These data suggest that dietary LCFAs, similar to MCFAs, are absorbed via blood vessels in patients with LC.

CONCLUSIONS

Rapid absorption of LCFAs by an alternative method occurred in patients with LC. This altered LCFA processing is likely related to upregulation of intestinal glycosylated CD36 and could contribute to pathogenesis in patients with LC.

Metabolic syndrome and ALA54THR polymorphism of fatty acid-binding protein 2 in obese patients

The prevalence of metabolic syndrome (MS) has been estimated to be approximately 25% of the population at large. A transition G to A at codon 54 of fatty acid-binding protein 2 (FABP2) results in an amino acid substitution (ala54 to Thr54), and this polymorphism was associated with some cardiovascular risk factors. The aim of our study was to investigate the relationship between MS and Thr54 polymorphism in the FABP2 gene in obese patients. A population of 750 (body mass index >30) obese patients was analyzed in cross-sectional survey. Bioimpedance, blood pressure, and serial assessment of nutritional intake with 3-day written food records and biochemical analysis were performed. The statistical analysis was performed for the combined Ala54/Thr54 and Thr54/Thr54 as a mutant group and wild-type Ala54/Ala54 as second group. Prevalence of MS with Adult Treatment Panel III definition was 49.7% (373 patients; 24.9% male and 75.1% female), and 50.3% of the patients had no MS (n = 377; 34.2% male and 65.8% female). Prevalence of FABP genotypes was similar in patients with MS (55.5% wild genotype and 44.5% mutant genotype) and without MS (54.6% wild genotype and 45.4% mutant genotype). Prevalence of each criteria of MS was calculated in wild- and mutant-type genotypes, without statistical differences. No differences in anthropometric and biochemical parameters were detected between genotypes in the same group of MS. The finding of our study is the lack of association of the Thr54/Ala54 and Thr54/Thr54 FABP2 genotypes with MS.

Fatty acid-binding protein-2 genotype influences lipid and lipoprotein response to eicosapentaenoic acid supplementation in hypertriglyceridemic subjects

OBJECTIVE

The blood lipid-lowering effects of eicosapentaenoic acid (EPA) on hypertriglyceridemic subjects with different fatty acid-binding protein-2 (FABP2) genotypes have not, to our knowledge, been previously studied.

METHODS

Twenty-three FABP2 Ala54 and 23 Thr54 carriers with hypertriglyceridemia (triacylglycerol level >200mg/dL) were enrolled in this study. Participants took 2g of pure EPA daily for 8 wk. Fasting blood lipid and lipoprotein profiles were determined and changes from baseline were measured.

RESULTS

Blood lipids and lipoprotein responses of the FABP2 genotypes differed after EPA supplementation. Changes from baseline for triacylglycerol (19.2% decrease for Ala54 and 60.5% for Thr54, P<0.001), very low-density lipoprotein (20.0% decrease for Ala54 and 60.5% for Thr54, P<0.001), apolipoprotein CIII (22.8% decrease for Ala54 and 36.4% for Thr54, P<0.01), and high-density lipoprotein cholesterol (17.6% increase for Ala54 and 30.7% for Thr54, P<0.01) differed significantly between the two carrier groups. However, changes in total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B were not significant. EPA supplementation increased plasma EPA in Ala54 and Thr54 carriers. Although EPA supplementation increased the level of plasma EPA in both carrier groups, this effect was more pronounced in the Thr54 carriers.

CONCLUSION

Therefore, EPA consumption has more favorable effects on blood lipids of hypertriglyceridemics with Thr54 genotype rather than those with Ala54. The level of plasma EPA increases after EPA supplementation. Because the FABP2 Thr54 polymorphism appears to be prevalent in hypertriglyceridemic subjects, increasing EPA intake in these subjects could be an effective strategy for reducing blood triacylglycerol concentration.

Role of intestinal transporters in neonatal nutrition: carbohydrates, proteins, lipids, minerals, and vitamins

To support rapid growth and a high metabolic rate, infants require enormous amounts of nutrients. The small intestine must have the complete array of transporters that absorb the nutrients released from digested food. Failure of intestinal transporters to function properly often presents symptoms as "failure to thrive" because nutrients are not absorbed and as diarrhea because unabsorbed nutrients upset luminal osmolality or become substrates of intestinal bacteria. We enumerate the nutrients that constitute human milk and various infant milk formulas, explain their importance in neonatal nutrition, then describe for each nutrient the transporter(s) that absorbs it from the intestinal lumen into the enterocyte cytosol and from the cytosol to the portal blood. More than 100 membrane and cytosolic transporters are now thought to facilitate absorption of minerals and vitamins as well as products of digestion of the macronutrients carbohydrates, proteins, and lipids. We highlight research areas that should yield information needed to better understand the important role of these transporters during normal development.

Fatty acid- and cholesterol transporter protein expression along the human intestinal tract

Background

Protein distribution profiles along the human intestinal tract of transporters involved in the absorption of cholesterol and long-chain fatty acids (LCFA) have been scarcely evaluated.

Methodology/Principal Findings

In post-mortem samples from 11 subjects, intestinal transporter distribution profiles were determined via Western Blot. Differences in transporter protein levels were statistically tested using ANOVA and Tukey's Post Hoc comparisons. Levels in all segments were expressed relative to those in duodenum. Except for ABCG5 and FATP4, levels (mean±SEM) were the highest in the ileum. For ABCA1, ileal levels (1.80±0.26) differed significantly from those in duodenum (P = 0.049) and proximal colon (0.92±0.14; P = 0.029). ABCG8 levels in ileum (1.91±0.30) differed from those in duodenum (P = 0.041) and distal colon (0.84±0.22; P = 0.010) and jejunum (1.64±0.26) tended to be higher than distal colon (0.84±0.22; P = 0.087). Ileal NPC1L1 levels (2.56±0.51) differed from duodenum levels (P = 0.019) and from distal colon (1.09±0.22; P = 0.030). There was also a trend (P = 0.098) for higher jejunal (2.23±0.37) than duodenal NPC1L1 levels. The levels of ABCG5 did not correlate with those of ABCG8. FAT/CD36 levels in ileum (2.03±0.42) differed from those in duodenum (P = 0.017), and proximal and distal colon (0.89±0.13 and 0.97±0.15 respectively; P = 0.011 and P = 0.014). FABPpm levels in ileum (1.04±0.13) differed from proximal (0.64±0.07; P = 0.026) and distal colon (0.66±0.09; P = 0.037).

Conclusions/Significance

The distribution profiles showed a bell-shape pattern along the GI-tract with the highest levels in ileum for ABCA1, ABCG8, NPC1L1, FATCD36 and FABPm, suggesting a prominent role for ileum in transporter-mediated uptake of cholesterol and LCFAs.

Influence of Ala54Thr polymorphism of fatty acid-binding protein 2 on weight loss and insulin levels secondary to two hypocaloric diets: a randomized clinical trial

OBJECTIVE

A transition G to A at codon 54 of FABP2 was associated with high insulin resistance and different dietary response. The aim of our study was to investigate the influence of this polymorphism on weight loss and metabolic changes secondary to two hypocaloric diets.

SUBJECTS AND METHODS

A sample of 204 obesity patients was analyzed. Before and after 2 months of hypocaloric diet, a nutritional evaluation was performed. Patients were randomly allocated to diet I (low-fat diet) or II (low carbohydrate diet).

RESULTS

With diet Type I and in the wild group (Ala54/Ala54), BMI, weight, fat mass, waist circumference, waist to hip ratio, systolic and diastolic blood pressures, total cholesterol, triglyceride and insulin levels decreased. In the mutant group (Ala54/Thr54 and Thr54/Thr54), BMI, weight, waist circumference and fat mass decreased. In the wild group with diet Type II, the same parameters that group I decreased and glucose levels, too. In the mutant group, BMI, weight, waist circumference and fat mass decreased. Only leptin levels have a significant decrease in the wild group with both diets (diet I: 30.7%; p<0.05 and diet II: 15.85%; p<0.05).

CONCLUSION

Similar weight loss is associated with different changes, depending on the FABP genotype with both diets. Weight loss is associated with a more deep decrease in serum leptin concentration with low-fat diet.

Influence of Ala54Thr polymorphism of fatty acid-binding protein-2 on clinical results of biliopancreatic diversion

OBJECTIVE

Bariatric surgery is the most effective long-term treatment for morbid obesity, reducing obesity-associated comorbidities. The purpose of the present study was to evaluate the fatty acid-binding protein-2 Ala54Thr polymorphism outcomes 1 y after biliopancreatic diversion in morbidly obese patients.

METHODS

A sample of 41 morbidly obese patients (body mass index >40 kg/m(2)) were operated upon from December 2004 to December 2006. Weight, fat mass, blood pressure, basal glucose, triacylglycerides, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol were measured at the basal visit and at each visit. The frequency of patients with diabetes mellitus, hypertension, and hyperlipidemia was recorded at each visit.

RESULTS

Twenty-three patients (56.1%) had genotype Ala54/Ala54 (wild group) and 18 patients had genotype Ala54/Thr54 (15 patients, 36.5%) or Thr54/Thr54 (3 patients, 7.4%; mutant group). In the wild group, body mass index, weight, fat mass, systolic blood pressure, glucose, total cholesterol, low-density lipoprotein cholesterol, and triacylglycerol concentrations decreased. Diastolic blood pressure remained unchanged. In the mutant group, the same parameters improved, without statistical differences from the wild group. Initial excess weight percent loss at 1 y of follow-up was similar in both genotype groups (61.8% versus 61.9%, NS).

CONCLUSION

Polymorphism Ala54Thr of fatty acid-binding protein did not have an effect on weight loss or clinical outcomes after bariatric surgery.

Genes, diet and type 2 diabetes mellitus: a review

Diabetes mellitus is widely recognized as one of the leading causes of death and disability. While insulin insensitivity is an early phenomenon partly related to obesity, pancreatic beta-cell function declines gradually over time even before the onset of clinical hyperglycemia. Several mechanisms have been proposed to be responsible for insulin resistance, including increased non-esterified fatty acids, inflammatory cytokines, adipokines, and mitochondrial dysfunction, as well as glucotoxicity, lipotoxicity, and amyloid formation for beta-cell dysfunction. Moreover, the disease has a strong genetic component, although only a handful of genes have been identified so far. Diabetic management includes diet, exercise and combinations of antihyperglycemic drug treatment with lipid-lowering, antihypertensive, and antiplatelet therapy. Since many persons with type 2 diabetes are insulin resistant and overweight, nutrition therapy often begins with lifestyle strategies to reduce energy intake and increase energy expenditure through physical activity. These strategies should be implemented as soon as diabetes or impaired glucose homoeostasis (pre-diabetes) is diagnosed.

Influence of ALA54THR Polymorphism of Fatty Acid Binding Protein 2 on Lifestyle Modification Response in Obese Subjects

BACKGROUND/AIM

It has been found that the expression of fatty acid binding protein 2 (FABP2) mRNA is under dietary control. A G-to-A transition at codon 54 of FABP2 results in an amino acid substitution (from Ala 54 to Thr 54). This polymorphism was associated with high insulin resistance and high fasting insulin concentrations. The aim of our study was to investigate the influence of Thr54 polymorphism in the FABP2 protein on the response to a lifestyle modification (Mediterranean hypocaloric diet and exercise) in obese patients.

METHODS

A population of 69 obese (body mass index > 30) nondiabetic outpatients was analyzed in a prospective way. Before and after 3 months of the lifestyle modification program, indirect calorimetry, tetrapolar electrical bioimpedance measurement, blood pressure recording, serial assessment of the nutritional intake (3 days of written food records), and biochemical analysis were performed. The lifestyle modification program consisted of a hypocaloric diet (1,520 kcal; 52% carbohydrates, 25% lipids, and 23% proteins). The exercise program consisted of aerobic exercise for at least three times/week (60 min each). Statistical analysis was performed for combined Ala54/Thr54 and Thr54/Thr54 as a mutant group and wild-type Ala54/Ala54 as second group.

RESULTS

The mean age was 45.5 +/- 16.7 years, the mean body mass index was 34.1 +/- 5.1, and there were 14 males (20.3%) and 55 females (79.7%) with a weight loss of 3.17 +/- 3.5 kg (3.5%). Thirty-seven patients (53.6%) had the genotype Ala54/Ala54 (wild-type group) and 32 (46.4%) patients either the genotype Ala54/Thr54 (26 patients, 30.2%) or the genotype Thr54/Thr54 (6 patients, 16.2%). The percentage of responders (weight loss) was similar in both groups (89.2 vs. 90.6%). In the wild-type group, body mass index, weight, fat mass, low-density lipoprotein cholesterol level, and waist circumference decreased, whereas the VO2 (oxygen consumption) increased. In the mutant group, glucose, body mass index, weight, waist circumference, and systolic blood pressure decreased, and VO2 increased. No differences were detected between basal values in both groups. Only the leptin levels showed a significant decrease in the wild-type group (23.85%; p < 0.05), with no statistically significant difference in the mutant group (2.59%; NS). Resistin, tumor necrosis factor alpha, interleukin 6, insulin, and C-reactive protein remained without changes in both groups.

CONCLUSIONS

Weight loss is associated with different changes, depending on the FABP2 genotype. Carriers of the Thr54 allele have a different response than wild-type obese subjects, with a significant decrease of systolic blood pressure and glucose levels in Thr54 carriers and a significant decrease in fat mass, low-density lipoprotein cholesterol, and leptin in wild-type patients.

Expression of PPAR, RXR isoforms and fatty acid transporting proteins in the rat and human gastrointestinal tracts

Dietary fatty acid (FA) absorption across the gastrointestinal (GI) tract is of critical importance for sustenance, however, excessive FA absorption has also been linked to metabolic syndrome and associated disorders. The expression of isoforms that regulate the dietary FA absorption are not as well characterized in the GI tract as they are elsewhere. Peroxisome proliferator-activated receptors (PPARalpha, beta, and gamma) and 9-cis-retinoic acid receptors (RXRalpha, beta, and gamma) are nuclear hormone transcription factors that control FA homeostasis, in part through the regulation of expression of membrane-bound FA transporting proteins. The present study was designed to elucidate the expression of PPAR and RXR isoforms and FA transporting proteins (FABPpm and FAT/CD36) in the rat and human GI tracts using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemical staining. The results revealed rat GI expression of all the PPAR and RXR isoforms, FABPpm and FAT/CD36. PPARalpha, PPARbeta, PPARgamma, RXRalpha, FABPpm, and FAT/CD36 isoforms exhibited ubiquitous expression in human GI tract, whereas RXRbeta was not detected. RXRgamma was observed in a majority of the human GI samples. These results provide a physiological foundation for rational drug design and drug delivery for the mitigation of metabolic syndrome and associated disorders to normalize intestinal FA absorption.

Intestinal solute carriers: an overview of trends and strategies for improving oral drug absorption

A large amount of absorptive intestinal membrane transporters play an important part in absorption and distribution of several nutrients, drugs and prodrugs. The present paper gives a general overview on intestinal solute carriers as well as on trends and strategies for targeting drugs and/or prodrugs to these carriers in order to increasing oral bioavailability and distribution. A number of absorptive intestinal transporters are described in terms of gene and protein classification, driving forces, substrate specificities and cellular localization. When targeting absorptive large capacity membrane transporters in the small intestine in order to increase oral bioavailabilities of drug or prodrug, the major influence on in vivo pharmacokinetics is suggested to be dose-dependent increase in bioavailability as well as prolonged blood circulation due to large capacity facilitated absorption, and renal re-absorption, respectively. In contrast, when targeting low-capacity transporters such as vitamin transporters, dose independent saturable absorption kinetics are suggested. We thus believe that targeting drug substrates for absorptive intestinal membrane transporters could be a feasible strategy for optimizing drug bioavailability and distribution.

Lymphatic delivery and in vitro pancreatic lipase hydrolysis of glycerol esters of conjugated linoleic acids in rats

We examined the intestinal delivery of conjugated linoleic acids (CLA) given in their triacylglycerol form in the mesenteric lymph of rats. Emulsions containing a mixture of the trilinolein/triester of CLA (9:1) and a tri-[1-(14)C]-linoleyl-sn-glycerol tracer were administered by force-feeding. Lymph was collected over two time periods (0-6 and 6-24 h), and the apparent recovery of CLA was determined relative to that of [1-(14)C]-18:2(n-6). A mixture of CLA-triester/trilinolein (1:9), trilinolein or CLA-triester was separately subjected to pancreatic lipase hydrolysis in vitro to determine whether the lymphatic recovery of CLA was correlated with the initial step of digestion. Lymphatic recovery of CLA was similar to that of 18:2(n-6) (95.6+/-9.0% of the linoleic acid recovery), and isomer repartition was similar in lymph and in the oil fed, indicating that all the CLA isomers were equally absorbed by the enterocytes. Unexpectedly, the in vitro release of CLA into the absorbable forms (free fatty acids and 2-monoacyl-sn-glycerol) was consistently lower than that of 18:2(n-6). Moreover, the 9c, 11t-isomer of CLA was also released faster into the absorbable forms than its 10t,12c homolog (P = 0.05). We cannot ascribe a distinct cellular accumulation or a difference in the biological effects of different CLA isomers on the ground of a selective intestinal absorbability. Also, the physiological conditions prevailing in vivo in the digestive tract are likely to overcome the relative resistance of CLA ester bonds to pancreatic lipase hydrolysis and allow a lymphatic recovery of CLA similar to that of linoleic acid.

Genetic predictors of plasma lipid response to diet intervention

There is a growing interest in determining the genetic predictors of plasma lipid response to diet intervention. Several candidate gene loci, namely, apolipoprotein (APO) A1, APOA4, APOC3, APOB, APOE, CETP, LPL, and FABP2, have been shown to explain a significant, but still rather small, proportion of the interindividual variability in dietary response. Other gene loci code for products that play a relevant role in lipoprotein metabolism and are prime candidates for future studies (ie, CYP7). Future progress in this complex area will come from experiments carried out using animal models and from carefully controlled dietary protocols in humans.

Chick small intestine brush border contains lipase and phospholipase activity

1. Uptake of triglycerides and phosphoglycerides was demonstrated in ligated washed chick intestinal segments in situ. Mucosal uptake was observed both in the jejunum and ileum of chicks and was not accompanied by significant luminal hydrolysis of acylglycerides. 2. Brush border membrane vesicles were prepared and lipase and phospholipase activities were demonstrated. These activities were enriched in parallel to the increase in activity of maltase and gamma-glutamyl transpeptidase in all small intestinal areas. 3. In order to determine if the pancreatic and brush border membrane lipolytic activities were similar different properties of these activities were examined. The relative activities of pancreatic and brush border membranes towards triolein and phosphatidylcholine differed. The pH-triolein activity curve and the use of different additives showed some diverging effects between the activities. These differences were not, however, sufficient to conclude that the brush border activity towards triolein is distinct from that of pancreatic lipase. 4. Lipolytic activity in the brush border may play a role in acylglyceride digestion, uptake and transport in the small intestine of the chick.

Localization and regulation of the putative membrane fatty-acid transporter (FAT) in the small intestine. Comparison with fatty acid-binding proteins (FABP)

The expression of the putative membrane fatty-acid transporter (FAT) was investigated in the small intestine. The FAT mRNA level was higher in the jejunum than in the duodenum and was lower in the ileum, as observed for cytosolic fatty-acid-binding proteins (FABP) expressed in this tissue. No FAT transcript was found in the stomach or colon. FAT mRNA was constitutively expressed in the epithelial cells located in the upper two thirds of villi, while it was undetectable in the crypt cells and submucosal cells. In jejunal mucosa, immunochemical studies showed that FAT protein was limited to the brush border of enterocytes. No fluorescence was found in the goblet cells. To determine whether FAT responded to changes in fat intake, as reported for FABP, the effect of two high-fat diets, which essentially contained either medium-chain fatty acids or long-chain fatty acids (sunflower-oil diet), was investigated. The sunflower-oil diet greatly increased FAT mRNA abundance throughout the small intestine. In contrast, a weak effect of medium-chain fatty acids was observed only in the jejunum. As found for FABP expression, treatment with the hypolipidemic drug bezafibrate affected FAT expression. These data demonstrate that FAT and FABP are co-expressed in enterocytes, as has been shown in adipocytes, myocytes and mammary cells. The data suggest that these membrane and cytosolic proteins might have complementary functions during dietary-fat absorption.