Lipid Absorption Capacity Research Articles

Techno-functional properties of black soldier fly (Hermetia illucens) larvae

Quality, nutritional and techno-functional properties of whole black soldier fly larvae (BSFL) were investigated to determine its potential as a food ingredient. The effect of age, feed and killing method (blanching or frozen) on these characteristics were determined; all three factors influenced the characteristics investigated. The BSFL were freeze dried and milled into a powder and analysed for physical (larvae size, pH, colour, proximate composition) and techno-functional properties (water absorption capacity, lipid absorption capacity, emulsifying activity, emulsifying stability, and gel formation). Older larvae were found to have a higher ash, fat, and chitin content, whilst having lower moisture and protein contents than the younger larvae (P<0.05). The pH of the BSFL ranged from 6.79 (frozen) to 8.94 (blanched), with blanching causing a lighter coloured BSFL than freezing. The water absorption capacity of the BSFL ranged from 56.27 to 80.77% and the lipid absorption capacity ranged from 50.83 to 68.62%, both of which are lower than that of other insect species. Five-day aged frozen larvae could form a gel at 5% inclusion, whilst blanching had a negative effect on gel formation and required an inclusion of 30% BSFL to form a gel. Emulsion capacity (EC) (43%) and stability (ES) (32%) compared well to other insect species; however, blanching had a negative effect on these properties, reducing both EC (10%) and ES (5%). Overall, the results indicate that freezing is the preferred killing method for ingredient functionality and these findings demonstrate some promising potential for BSFL as a functional ingredient.

Retraction Note to: Effect of a high fat diet on lipid absorption and fatty acid transport in a rat model of short bowel syndrome

Long chain fatty acids (LCFAs) appear to be powerful stimulants for small bowel adaptation in patients with short bowel syndrome (SBS). However, the dietary lipid content may alter intestinal lipid transport. The aim of this study was to investigate the effects of a high fat diet (HFD) on in vivo lipid absorption and molecular and cellular mechanisms of LCFAs uptake by the remaining bowel. Male Sprague-Dawley rats (240–280) were randomly assigned to one of three groups: sham rats fed normal chow (sham-NC), SBS rats fed NC (SBS-NC) and SBS rats fed HFD (SBS-HFD). SBS rats underwent a 75% small bowel resection. Rats were sacrificed on day 3 or 14. Body weight, fat intake and fat clearance (total fecal fat) were measured twice a week. Fat absorbability was calculated as intake minus clearance and was expressed as percent of intake. Total RNA from the mucosa of duodenum, jejunum and ileum was extracted using TRIZOL Reagent. Northern blot analysis was performed to determine FAT/CD36 mRNA levels. Enterocyte LCFA transport was measured on day 14. LCFA uptake was determined by measuring cellular [3H]-oleate uptake over time (4–120 s). Mean (±SE) FAT/CD36 mRNA levels and oleate uptake kinetic parameters were analyzed using ANOVA. Fat absorbability diminished after bowel resection, suggesting fat malabsorption. Remaining bowel in SBS-NC rats responded by an increase in FAT/CD36 mRNA levels in the duodenum and ileum on day 3, and the duodenum and jejunum on day 14 compared to sham-NC animals, and was accompanied by an increase in enterocyte LCFA transport in all segments. Exposure to a HFD for 14 days resulted in significantly increased fat absorbability after 3 days compared to SBS-NC rats. However, FAT/CD36 mRNA levels (vs. SBS-NC) decreased in all segments on day 3. On day 14, FAT/CD36 mRNA levels were decreased in the duodenum and ileum and were accompanied by reduced oleate uptake by isolated enterocytes in the ileum (vs. SBS-NC). In a rat model of SBS, early high fat diet increased lipid absorptive capacity of the intestinal remnant as seen by increased fat absorbability. The main mechanisms of this effect may be an acceleration of structural intestinal adaptation resulting in an increased number of enterocytes. However, at molecular and cellular levels HFD decreased mucosal FAT/CD36 mRNA levels and oleic acid uptake by isolated enterocytes.

Propiedades y posibles aplicaciones de las proteínas de salvado de trigo

El salvado de trigo se destina principalmente al consumo animal, por lo que algunos de sus componentes son subutilizados, representando oportunidades de valor agregado. Constituye las capas externas del grano y contiene hasta 18 % en peso de proteínas con mejor calidad que las de la harina. Estas proteínas no son aprovechadas debido a que la mayoría están protegidas por una matriz de polisacáridos, indigerible para el sistema gastrointestinal humano, por lo que es necesaria su extracción. Tradicionalmente, las proteínas de salvado han sido recuperadas mediante extracción alcalina y se han propuesto como ingredientes para la elaboración de productos alimenticios. Sin embargo, su uso es casi inexistente, debido a que los procesos de extracción son agresivos y no redituables. El objetivo del presente trabajo fue describir las propiedades de las proteínas del salvado de trigo, así como sus usos potenciales. Entre sus propiedades destacan la digestibilidad, el per l de aminoácidos y la capacidad de absorción de grasa. La fracción soluble en agua de estas proteínas, por su fácil extracción, podría tener valor agregado al utilizarse en tecnologías emergentes: como fuente de péptidos bioactivos, en la producción de nanopartículas con aplicaciones industriales o como matrices para procesos de biomineralización artificial.

Lipid is absorbed in the stomach by epithelial neoplasms (adenomas and early cancers): a novel functional endoscopy technique.

Background and study aims: The authors have successfully demonstrated that the white opaque substance (WOS) identified in gastric epithelial neoplasms is an accumulation of minute lipid droplets on the epithelial neoplasm. It is not known whether the lipid droplets originate from externally ingested lipids (typically foods). The purpose of this study was to investigate whether the oral ingestion of foods containing emulsified fats increases the density of the WOS in epithelial neoplasms. Patients and methods: We examined 92 gastric epithelial neoplastic lesions in 89 patients. The patients were given emulsified fatty foods before the procedure, and magnifying endoscopy with narrow-band imaging (M-NBI) was used to image the lesions. An increase in WOS density after the ingestion of emulsified fatty foods was defined as a positive fat-loading test result.The patients were divided into the following groups: control group, no emulsified fat administered; group 1, fatty food administered 16 hours prior; group 3, fatty food administered both 16 and 4 hours prior. The proportion of positive fat-loading test results was determined in all groups. Results: The rates of positive fat-loading test results were as follows: control group, 9 %; group 1, 26 %; group 2, 52 %; group 3, 78 %. The increase in the rates of positive fat-loading test results in groups 2 and 3 relative to the rate in the control group was statistically significant (chi-squared test). Conclusions: This study demonstrated for the first time that the ingestion of external lipids causes lipid droplets to aggregate in situ on the gastric epithelial neoplasm. These results can be used to develop a novel functional endoscopy technique that harnesses the lipid absorption capacity of neoplasms.

Isolation of bioactive polysaccharide from acorn and evaluation of its functional properties

The aim of this study was to evaluate the prebiotic potential and some functional properties of polysaccharides isolated from acorn fruit. The FTIR spectrum of isolated acorn polysaccharide (IAP) showed the typical bands corresponding to sugars and polysaccharides. The IAP was resistant to simulated acidic and enzymatic digestion even more than Inulin (In). The prebiotic activity, which was tested using IAP as a carbon source, showed significant increase in the growth and viability of Lactobacillus plantarum A7 (probiotic). Viability of Lactobacillus plantarum A7 in IAP and In supplemented media was stable even after 72h, whereas in glucose supplemented medium, bacterial growth showed a notable decrease after 24h. Lipid absorption capacity (LAC) and water holding capacity (WHC) of IAP were 5.44±0.02 (g oil/g DM) and 4.33±0.03 (g water/g DM), respectively, which were comparable to some dietary fibers and were more than In. IAP scavenged DPPH radicals by 82.24%. IAP was found to have a high scavenging ability compared to the reference prebiotic (In), giving a scavenging ability of about 20%. Therefore, due to prebiotic capability, high WHC, LAC and good antioxidant activity, IAP can be a suitable candidate for technological applications and health improving effects in functional food.

From fatty-acid sensing to chylomicron synthesis: Role of intestinal lipid-binding proteins

Today, it is well established that the development of obesity and associated diseases results, in part, from excessive lipid intake associated with a qualitative imbalance. Among the organs involved in lipid homeostasis, the small intestine is the least studied even though it determines lipid bioavailability and largely contributes to the regulation of postprandial hyperlipemia (triacylglycerols (TG) and free fatty acids (FFA)). Several Lipid-Binding Proteins (LBP) are expressed in the small intestine. Their supposed intestinal functions were initially based on what was reported in other tissues, and took no account of the physiological specificity of the small intestine. Progressively, the identification of regulating factors of intestinal LBP and the description of the phenotype of their deletion have provided new insights into cellular and molecular mechanisms involved in fat absorption. This review will discuss the physiological contribution of each LBP in the main steps of intestinal absorption of long-chain fatty acids (LCFA): uptake, trafficking and reassembly into chylomicrons (CM). Moreover, current data indicate that the small intestine is able to adapt its lipid absorption capacity to the fat content of the diet, especially through the coordinated induction of LBP. This adaptation requires the existence of a mechanism of intestinal lipid sensing. Emerging data suggest that the membrane LBP CD36 may operate as a lipid receptor that triggers an intracellular signal leading to the modulation of the expression of LBP involved in CM formation. This event could be the starting point for the optimized synthesis of large CM, which are efficiently degraded in blood. Better understanding of this intestinal lipid sensing might provide new approaches to decrease the prevalence of postprandial hypertriglyceridemia, which is associated with cardiovascular diseases, insulin resistance and obesity.

Doxorubicin treatment inhibits PPARγ and may induce lipotoxicity by mimicking a type 2 diabetes-like condition in rodent models

Doxorubicin-treated animals show elevated serum triglyceride and blood glucose levels. Adipocytes play an important role in buffering blood glucose and lipids. A raise in serum lipid level triggers adipogenesis in order to increase the lipid absorption capacity of adipose tissue. Doxorubicin inhibits adipogenesis through the down-regulation of PPARγ, a crucial component of the lipid metabolic pathway which controls the expression of glucose and fatty acid transporters. Doxorubicin-mediated down-regulation of PPARγ inhibits blood glucose and lipid clearance thereby causing hyperglycemia and hyperlipidemia resulting in lipotoxicity, glucotoxicity, inflammation and insulin resistance. Therefore we hypothesize that doxorubicin treatment could mimic a type 2 diabetic condition.

The effects of retinoblastoma (Rb) deletion on intestinal lipid absorption

BackgroundThe Retinoblastoma protein (Rb) may play a role in modulating the absorption of lipids within the small bowel. Rb null mice are characterized by an increased intestinal surface area compared to wild‐type (WT) mice. This study investigates the effects of Rb deficiency on lipid absorptive capacity with normal and high fat diets.MethodsRb null and WT mice were maintained on normal and high fat diets for short and long–term periods. Mice where weighted weekly. Fat absorption and fecal fat were determined using an extraction protocol. Lean mass and body fat were determined via nuclear magnetic resonanceResultsNo differences in weight were found between Rb null and WT mice. The Rb null mice on normal chow had higher fecal fat compared to WT; however no significant difference in fat absorption was seen between the groups. Similar results were observed after the same mice were placed on a short‐term high fat diet. An extended high fat diet showed Rb null mice maintained a higher fecal fat while fat absorption increased in WT mice. No significant differences in body fat or lean mass were found between Rb null and WT mice on a prolonged high fat diet.ConclusionRegardless of the type of diet given, Rb null mice absorb lipids at a lower capacity compared to WT mice. Enhanced bowel surface area seems to serves no advantage in regards to lipid absorption.Research supported by NIH grant DK 59288‐06A2

Development and Physiological Regulation of Intestinal Lipid Absorption. I. Development of intestinal lipid absorption: cellular events in chylomicron assembly and secretion

The newborn mammal must efficiently absorb dietary fat, predominantly as triacylglycerol, and produce chylomicrons to deliver this lipid to peripheral tissues. The cellular mechanisms involved in enterocyte chylomicron assembly have recently been elucidated, and data on their regulation in the immature gut are beginning to emerge. This review focuses on key proteins involved in chylomicron assembly: apolipoprotein B-48, microsomal triglyceride transfer protein, and apolipoprotein A-IV. Recent studies support a role for apolipoprotein A-IV in enhancing chylomicron secretion by promoting production of larger particles. These proteins are regulated in a manner to maximize the lipid absorptive capacity of the newborn intestine.

Chronic high-fat diet affects intestinal fat absorption and postprandial triglyceride levels in the mouse

The effects of chronic fat overconsumption on intestinal physiology and lipid metabolism remain elusive. It is unknown whether a fat-mediated adaptation to lipid absorption takes place. To address this issue, mice fed a high-fat diet (40%, w/w) were refed or not a control diet (3%, w/w) for 3 additive weeks. Despite daily lipid intake 7.7-fold higher than in controls, fecal lipid output remained unchanged in mice fed the triglyceride (TG)-rich diet. In situ isolated jejunal loops revealed greater [1-(14)C]linoleic acid uptake without TG accumulation in mucosa, suggesting an increase in lipid absorption capacity. Induction both in intestinal mitotic index and in the expression of genes involved in fatty acid uptake, trafficking, and lipoprotein synthesis was found in high-fat diet mice. These changes were lipid-mediated, in that they were fully abolished in mice refed the control diet. A lipid load test performed in the presence or absence of the LPL inhibitor tyloxapol showed a sustained blood TG clearance in fat-fed mice likely attributable to intestinal modulation of LPL regulators (apolipoproteins C-II and C-III). These data demonstrate that a chronic high-fat diet greatly affects intestinal physiology and body lipid use in the mouse.

Dietary manipulation of the sow milk does not influence the lipid absorption capacity of the progeny

A control diet without supplemental fat and four diets containing 8% of coconut oil, rapeseed oil, fish oil or sunflower oil were fed to lactating sows in order to investigate the lipid absorption capacity of their progeny in terms of pancreatic enzyme activity, hormonal regulation, and bile salt concentration. In addition, the effect of age was studied during the four week suckling period, and during a three week postweaning period, in which a standard weaner diet was fed to all piglets. It is concluded that fat source and level in the maternal diet plays a minor role in comparison to piglet age with regard to lipid absorption capacity of the progeny postweaning.

Effect of a high fat diet on lipid absorption and fatty acid transport in a rat model of short bowel syndrome.

Long chain fatty acids (LCFAs) appear to be powerful stimulants for small bowel adaptation in patients with short bowel syndrome (SBS). However, the dietary lipid content may alter intestinal lipid transport. The aim of this study was to investigate the effects of a high fat diet (HFD) on in vivo lipid absorption and molecular and cellular mechanisms of LCFAs uptake by the remaining bowel. Male Sprague-Dawley rats (240-280) were randomly assigned to one of three groups: sham rats fed normal chow (sham-NC), SBS rats fed NC (SBS-NC) and SBS rats fed HFD (SBS-HFD). SBS rats underwent a 75% small bowel resection. Rats were sacrificed on day 3 or 14. Body weight, fat intake and fat clearance (total fecal fat) were measured twice a week. Fat absorbability was calculated as intake minus clearance and was expressed as percent of intake. Total RNA from the mucosa of duodenum, jejunum and ileum was extracted using TRIZOL Reagent. Northern blot analysis was performed to determine FAT/CD36 mRNA levels. Enterocyte LCFA transport was measured on day 14. LCFA uptake was determined by measuring cellular [3H]-oleate uptake over time (4-120 s). Mean (+/-SE) FAT/CD36 mRNA levels and oleate uptake kinetic parameters were analyzed using ANOVA. Fat absorbability diminished after bowel resection, suggesting fat malabsorption. Remaining bowel in SBS-NC rats responded by an increase in FAT/CD36 mRNA levels in the duodenum and ileum on day 3, and the duodenum and jejunum on day 14 compared to sham-NC animals, and was accompanied by an increase in enterocyte LCFA transport in all segments. Exposure to a HFD for 14 days resulted in significantly increased fat absorbability after 3 days compared to SBS-NC rats. However, FAT/CD36 mRNA levels (vs. SBS-NC) decreased in all segments on day 3. On day 14, FAT/CD36 mRNA levels were decreased in the duodenum and ileum and were accompanied by reduced oleate uptake by isolated enterocytes in the ileum (vs. SBS-NC). In a rat model of SBS, early high fat diet increased lipid absorptive capacity of the intestinal remnant as seen by increased fat absorbability. The main mechanisms of this effect may be an acceleration of structural intestinal adaptation resulting in an increased number of enterocytes. However, at molecular and cellular levels HFD decreased mucosal FAT/CD36 mRNA levels and oleic acid uptake by isolated enterocytes.

Impaired enterocyte triglyceride synthesis after trauma-hemorrhage and resuscitation.

Although gut lipid absorptive capacity is depressed after trauma and hemorrhagic shock, it remains unknown whether this is associated with an impairment in the enterocyte triglyceride (TG) synthesis, and if so, whether villus or crypt cells participate in the lipid absorption under such conditions. To study this, midline laparotomy (i.e., trauma induction) was performed in the rats, and then the animals were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of shed blood volume was returned in the form of Ringer's lactate. The rats were then resuscitated with four times the volume of maximal bleedout with Ringer's lactate over 60 min. For lipid loading test, 1 mL of olive oil was given intraduodenally as a bolus injection upon the completion of resuscitation. The enterocytes along the crypt-villus axis from the proximal small intestine were isolated at either 0, 1.5, or 5 h after fat feeding. The intracellular and pre-chylomicron TG contents as well as the microsomal enzyme activities associated with TG synthesis were determined thereafter. The results indicated that intracellular and pre-chylomicron TG contents and lipid esterifying enzyme (i.e., acyl-coenzyme A:monoglyceride acyltransferase) activity decreased significantly in villus tip cells after trauma-hemorrhage and resuscitation. The intracellular TG content and lipid esterifying enzyme activity in crypt cells after trauma and hemorrhagic shock were also reduced. However, there was no significant decrease in pre-chylomicron TG content in the crypt cells isolated from trauma-hemorrhaged rats. It is unlikely that crypt cells participate in lipid transport after trauma and hemorrhagic shock. In contrast, the TG synthesis in villus tip cells decreased significantly following trauma-hemorrhage and resuscitation, which may contribute, at least in part, to the impaired gut lipid absorptive capacity observed under such conditions.

INTESTINAL ALKALINE PHOSPHATASE

Although studies have indicated that the gut lipid absorptive capacity is impaired after trauma and hemorrhagic shock, the mechanism responsible for this remains unknown. The aim of this study, therefore, was to determine whether intestinal alkaline phosphatase (IAP) plays any role in the depressed gut lipid absorptive function observed under such conditions. To determine this, 5 cm midline laparotomy (i.e., trauma induced) was performed in the rats, and animals were then bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of shed blood volume was returned in the form of Ringer's lactate. The rats were resuscitated with four times the volume of maximal bleedout with Ringer's lactate over 60 min. For in vivo lipid loading test, 1 mL olive oil was given intraduodenally upon the completion of resuscitation. The enterocytes were isolated at either 0, 1.5, or 5 h after fat feeding, and the soluble, membranous and pre-chylomicron (pre-CM) IAP activities as well as triglyceride contents were determined thereafter. The results indicated that the soluble IAP activity in the villus tip cells isolated from trauma-hemorrhaged rats increased significantly at 0, 1.5, or 5 h after fat feeding. The pre-CMIAP activity, however, decreased markedly in villus tip cells at 1.5 or 5 h after lipid administration, which was associated with the decreased pre-CM triglyceride contents in villus tip cells under such conditions. The altered IAP activity in villus tip cells, therefore, appears to play a role in the depressed gut lipid absorption and transport following trauma-hemorrhage and resuscitation.

Impaired gut lipid absorptive capacity after trauma-hemorrhage and resuscitation.

Although the barrier function of the intestinal mucosa is impaired after hemorrhage, it remains unclear whether this is associated with a deficit in mucosal function. The aim of this study, therefore, was to determine whether trauma-hemorrhage affects the in vivo lipid absorptive capacity of the gut and, if so, to characterize the uptake process of free fatty acids in isolated enterocytes. To study this, rats were anesthetized, a laparotomy was performed (i.e., trauma was induced), and various blood vessels were cannulated. For in vivo lipid absorption, the main intestinal lymph vessel was cannulated and a jejunostomy feeding tube was inserted. The animals were bled to and maintained at a mean arterial pressure of 40 mmHg until 40% of shed blood volume was returned in the form of Ringer lactate. They were then resuscitated with four times the volume of maximal bleed out with Ringer lactate. The in vivo and in vitro lipid absorptive capacities were assessed by measuring lymph triglyceride output after a fat load and by determining the linoleic acid uptake rates on isolated enterocytes, respectively. The results show that the in vivo lipid absorption capacity of the gut is severely depressed after trauma-hemorrhage and resuscitation. Similarly, in enterocytes isolated from hemorrhaged rats, fatty acid uptake capacity, as reflected by the decreased maximal uptake rates, was significantly reduced: 1.2 +/- 0.2 and 2.6 +/- 0.6 nmol.min-1 x 10(6) cells-1 for hemorrhaged and sham, respectively. Thus gut lipid absorptive function is depressed after trauma-hemorrhage and resuscitation, which is at least partially due to the depressed uptake mechanism of the enterocyte.

PHYSICOCHEMICAL, FUNCTIONAL AND SENSORY PROPERTIES OF PROTEIN EXTRACTED FROM DESICCATED COCONUT

Coconut protein (CNP) was extracted from desiccated coconut in 1.0 M sodium chloride (1:15), precipitated by HCI, ultra filtered, and freeze‑dried. The physicochemical, functional, and sensory characteristics of the material were compared with those of soy protein. The composition and chemical analyses included measurements of protein, fat, moisture, carbohydrate, ash, minerals, and amino acids. Other measurements included determination of die contents of sulfhydryl and disulfide groups, hydrophobicity values, and electrophoretic patterns of CNP and soy protein. The bulk density of the protein preparations was also measured. Chemical analyses showed that CNP was comparable in overall composition to the reference soy protein with the exception of high sodium content (4.7%). Amino acid analysis revealed a higher content of arginine and a lower content of aspartic acid and lysine. A test for relatedness among, proteins (S ΔQ) showed very little similarity between the amino acid profiles of the two protein entities. CNP was found to be more hydrophobic than soy protein and contained slightly less sulthydryl and disulfide groups. The disparity in the above values was reflected in dissimilarity in the electrophoretic patterns between CNP and soy protein. CNP exhibited a lower solubility but possessed a similar water binding and a higher lipid absorption capacity than soy protein. Sensory evaluation using crackers prepared with different amounts of the two proteins showed that crackers with added CNP were preferred over crackers with added soy protein. The overall results of this study suggest a potential use of CNP as an alternative protein source to soy protein for use in manufactured foods where solubility is not a critical factor.

Perinatal ontogeny of fatty acid binding protein activity in porcine small intestine

Growth and functional maturation of porcine small intestine was characterized in relation to stage of perinatal development. Fatty acid binding activity of specific low molecular weight, cytosolic proteins (FABPs) was measured in the small intestinal mucosae of young pigs. Intestinal mucosa mass, soluble protein content, DNA content and oleic acid-binding capacity were determined for pigs (n=4) at −4, 2, 4, 7, 14, 22, 28 and 35 days of age. FABP activity of mucosa from the proximal half of intestine displayed a cubic pattern of change (P<.01) with age, increasing from 15.2 nmol oleic acid bound at −4 days to 542.1 nmol bound at 14 days. Oleic acid-binding decreased to 240 nmol at 22 days (day 1 postweaning) but remained elevated above preweaning values at day 28. Distal-region small intestinal FABP activity corresponded to 13.5 nmol oleic acid bound at −4 days, increased to 124.3 nmol bound at day 7, and decreased to 103.0 nmol bound at day 14. Immediately postweaning, distal-region intestinal FABP activity increased three-fold relative to the day 14 values. Proximal intestine FABP activities exceeded distal intestine activities for all days except at day 22. Total FABP activity, adjusted per mg DNA, exhibited a nine-fold increase in the proximal region of the small intestine between −4 days and day 7. The developmental variation in intestinal FABP activity suggests that FABPs may represent markers of neonatal intestinal differentiation and lipid absorptive capacity in the neonate.

Effect of ethanol on intestinal lipid absorption in the rat.

The effect of ethanol infusion on intestinal lipid absorption was studied in rats with a duodenal cannula. Rats were infused with ethanol overnight and ethanol was included in a trioleoylglycerol emulsion infusion given for 3 hr the next day. These rats were compared to control animals infused with glucose (isocalorically). The ethanol-infused rats had a greatly impaired lipid absorptive capacity. The monoacylglycerol and free fatty acid contents in the intestinal lumen in the ethanol-infused rats were 4- and 7-fold greater, respectively, than controls. The inhibition of absorption was not due to an effect of ethanol on lipolytic activity. The lipase content of the ethanol-infused rats was greater than controls and the separate infusion of monoacylglycerol and fatty acids demonstrated impaired absorption of these end products of lipolysis as compared to controls. To observe if these changes were due to an effect of ethanol on the enterocyte brush border membrane, the membrane lipids were analyzed. The phosphatidylcholine, lysophosphatidylcholine, and phosphatidylethanolanine content was reduced but not the neutral lipids, sphingomyelin, or phosphatidylserine. The uptake of fatty acid into intestinal rings was also shown to be impaired by ethanol infusion. Lastly, the specific activity of the neutral lipids remaining in the intestinal lumen after [3H]glycerol-labeled trioleoylglycerol-infusion was similar to controls even though the mass was much greater. It is concluded that ethanol impairs neutral lipid absorption due to an effect on the enterocyte brush border membrane and by increasing the efflux of low specific activity lipid from the enterocyte back out into the intestinal lumen. A potential pathway for this efflux is the recently described increased porosity of the apical junctional complex in response to ethanol infusion.