Mechanism of pH effect on oleic acid and cholesterol absorption in the rat

1987 ◽  
Vol 252 (4) ◽  
pp. G506-G510
Author(s):  
K. Chijiiwa ◽  
W. G. Linscheer
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Small Bowel ◽  
Ph Effect ◽  
Sodium Taurocholate ◽  
Cholesterol Absorption ◽  
The Other ◽  
Micellar Solutions ◽  
Solution Ph ◽  
Lower Ratio

Previous experiments [K. Chijiiwa and W. G. Linscheer, Am. J. Physiol. 246 (Gastrointest. Liver Physiol. 9): G492-G499, 1984] have shown higher rates of absorption of oleic acid (OA) and cholesterol (CH) from micellar solutions perfused through segments of small bowel at pH 5.5 than at pH 6.5. Both solutions contained equal amounts of these lipids in addition to sodium taurocholate (30 mM). It was hypothesized that there may be two reasons to explain this observation. First, the micelles of one of the two solutions (pH 6.5) became depleted of these lipids during the perfusion procedure, while the micelles of the other solution (pH 5.5) were kept saturated with these lipids by the presence of emulsified particles in the perfusate. Second, the pH difference resulted in a much lower ratio of protonated vs. ionized OA in the pH 6.5 solution. Most investigators assume that primarily protonated fatty acid (FA) is absorbed and very little ionized FA is absorbed. The purposes of the present study are to evaluate further the factor of lipid saturation of the micelles by comparison of rates of absorption from two partially lipid-depleted micellar solutions containing equal amounts of OA and CH, in which the micelles of one solution were much more lipid depleted than the micelles of the other. This was caused by the pH difference. The second purpose is to evaluate the effect of the pH-related difference in protonate vs. ionized OA on absorption of OA from nonmicellar aqueous solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative Effects of Bile Salt and Fatty Acid on Cholesterol Absorption in the Rat

1958 ◽  
Vol 193 (1) ◽  
pp. 41-46 ◽  
Author(s):  
George V. Vahouny ◽  
C. H. Woo ◽  
C. R. Treadwell
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Bile Salt ◽  
Sodium Taurocholate ◽  
Cholesterol Absorption ◽  
Thoracic Duct Lymph ◽  
Lipid Fractions ◽  
Duct Lymph ◽  
Bile Fistula ◽  
Relationship Of

The influence of various molar proportions of oleic acid and sodium taurocholate on the absorption of cholesterol and upon the lipid partition of thoracic duct lymph has been studied. In bile fistula rats a marked reduction of all lipid fractions of lymph was evident. The administration of oleic acid, taurocholate and cholesterol, singly or in various combinations to these animal preparations failed to elevate the lipid levels to those found in the fasting control animals having a normal bile circulation. The inclusion of up to 430 mg of taurocholate in an intragastric emulsion containing 50 mg of cholesterol and an excess of fatty acid failed to produce significant absorption of cholesterol, emphasizing the importance of the continuous circulation of the bile constituents for the absorption of cholesterol. In lymph fistula animals a molar relationship of oleic acid, taurocholate and cholesterol of 8:4:1 was found to be most effective for lipid and cholesterol absorption from the intestine and phospholipid production by the intestinal mucosa. Several levels of cholesterol greater than 50 mg were administered in emulsions in which the contents of fatty acid and bile salt were optimum for cholesterol absorption at the 50-mg level. No increase in absorption occurred either in absolute amounts or in percentage of the administered sterol. The results of these studies indicate the necessity of fatty acid, bile salt and cholesterol, present at the same time and in the proper molar amounts, for optimal transfer of fatty acid and cholesterol in the rat.

The Toxic Effects of Fatty Acids and Their Salts on the Balsam Woolly Aphid, Adelgespiceae (Ratz.)

1975 ◽  
Vol 5 (4) ◽  
pp. 515-522 ◽  
Author(s):  
George S. Puritch
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Saturated Fatty Acid ◽  
Capric Acid ◽  
The Other ◽  
Toxic Effects ◽  
Life Stages ◽  
Woolly Aphid ◽  
Oleic And Linoleic Acids

Fatty acids and their potassium soaps were screened for their toxicity to different life stages and eggs of the balsam woolly aphid (Adelgespiceae (Ratz.)). The most effective fatty acids for causing aphid mortality were in two major groups, one centering around capric acid (C10) within the low-chain saturated fatty acid series and the other around oleic acid (C18:1), within the unsaturated 18-carbon fatty acids. The potassium soaps were better aphicides than the corresponding acids; the soaps of caprylic, capric, oleic, and linoleic acids were the most effective. Eggs were less sensitive to the soaps than later stages of the aphid, and there was a large variation in their response to the soap treatments. The possibility of using fatty acids and soaps as a control for the balsam woolly aphid is discussed.

Factors Facilitating Cholesterol Absorption From the Intestine Via Lymphatic Pathways

1957 ◽  
Vol 188 (2) ◽  
pp. 342-346 ◽  
Author(s):  
George V. Vahouny ◽  
Isa Fawal ◽  
C. R. Treadwell
Keyword(s):  
Oleic Acid ◽  
Free Cholesterol ◽  
Sodium Taurocholate ◽  
Cholesterol Absorption ◽  
Intestinal Lumen ◽  
Thoracic Duct Lymph ◽  
Intragastric Administration ◽  
Lipid Fractions ◽  
Duct Lymph ◽  
Lymphatic Pathways

The lipid fractions of thoracic duct lymph in unanesthetized rats were determined following intragastric administration of saline-albumin emulsions containing various combinations of cholesterol, taurocholate and oleic acid. Sodium taurocholate or oleic acid alone produced significant increases in the total lipid, neutral fat and phospholipid fractions, but had no effect on the level of free and ester cholesterol. Administration of cholesterol alone was without effect on any of the fractions. The combination of taurocholate and oleic acid gave the same levels of lipid fractions as when they were administered singly except that there was an elevation of ester cholesterol indicating increased absorption of endogenous cholesterol. Cholesterol plus taurocholate or oleic acid produced the same increases in the fractions as the salt or acid alone except that with both combinations there were highly significant increases in the total and ester cholesterol fractions. Administration of the three factors together gave further increases in all fractions except neutral fat and free cholesterol. The amount of free cholesterol was constant throughout all groups, even in those in which there was absorption of exogenous cholesterol. The percentage of ester cholesterol in the total cholesterol of lymph ranged from 66 to 81 with the higher percentages in the groups where cholesterol absorption occurred. The esterification of the ‘extra’ cholesterol in lymph due to cholesterol absorption ranged from 86 to 92%. It is suggested that essentially all of the cholesterol transferred from the intestinal lumen to the lacteals is esterified.

Changes in Lipid Composition of Lymph During Cholesterol Absorption in the Rat

1957 ◽  
Vol 191 (1) ◽  
pp. 179-184 ◽  
Author(s):  
George V. Vahouny ◽  
C. R. Treadwell
Keyword(s):  
Oleic Acid ◽  
Total Nitrogen ◽  
Sodium Taurocholate ◽  
Experimental Period ◽  
Cholesterol Absorption ◽  
Thoracic Duct Lymph ◽  
Lipid Levels ◽  
Comparable Group ◽  
Lipid Fractions ◽  
Duct Lymph

Time studies of the appearance of lipid fractions in the thoracic duct lymph of rats were performed following the administration of emulsions containing cholesterol, oleic acid and sodium taurocholate. The influence of added protein on lipid levels and the total nitrogen of lymph was also studied. Addition of albumin to administered saline was without effect on lymph flow, lipid fractions or total nitrogen. In those animals receiving cholesterol, oleic acid and taurocholate, in addition to albumin, a rapid increase in total lipid was evident during the initial 3 hours, followed by a gradual fall in this fraction to near preabsorptive levels at the end of 9 hours. Comparable changes were observed in the ester cholesterol, neutral fat and phospholipid fractions. Animals receiving a similar emulsion lacking albumin displayed less marked increases in the lipid fractions which were, however, prolonged throughout the experimental period. In contrast to the other lipid fractions in this group, the amount of lymph cholesterol for the 24-hour period was significantly greater than in the comparable group receiving albumin. During cholesterol absorption in both experimental groups, the increase in total lymph cholesterol was attributable almost entirely to an increase in the esterified fraction, which comprised between 84 to 92% of the absorbed sterol.

Effect of intraluminal pH on cholesterol and oleic acid absorption from micellar solutions in the rat

1984 ◽  
Vol 246 (5) ◽  
pp. G492-G499
Author(s):  
K. Chijiiwa ◽  
W. G. Linscheer
Keyword(s):  
Oleic Acid ◽  
Small Bowel ◽  
Ph Effect ◽  
Fecal Excretion ◽  
Micellar Phase ◽  
Phase Measurements ◽  
Proximal Small Bowel ◽  
In Vitro Measurements ◽  
Bowel Segments

We have studied the effects of intraluminal pH on micellar solubilization and on absorption rate of oleic acid (OA) and cholesterol in proximal small bowel segments and the total small bowel in rats. In addition, pH effect on fecal excretion of [3H]cholesterol was studied over a period of 4 days after duodenal administration of cholesterol in solutions at different pH using beta-sitosterol as a nonabsorbable marker. Rates of absorption of OA and cholesterol were, respectively, 1.8 and 1.9 times higher at pH 5.5 in both proximal bowel segments as compared with pH 6.5 (P less than 0.001). Similar observations were made when the whole small bowel was perfused. At pH 5.5, 1.8 times more OA was absorbed and 1.5 times more cholesterol than at pH 6.5 (P less than 0.001). Also, fecal output of radioisotope following administration of pH 5.5 solution was only 47% of the excretion using the pH 6.5 solution. Excretion of beta-sitosterol, which serves as a nonabsorbable marker, was not affected by pH differences. In vitro measurements of micellar solubility at the two pH levels by ultracentrifugation showed that an increase of one pH unit resulted in a decreased number of particles in the oil phase (oleic acid and cholesterol in the emulsified particles in pH 6.5 solution is 37 and 34%, respectively, of that in the pH 5.5 solution) due to increased solubilization into the micellar phase. Measurements of monomer activities of OA and cholesterol using a polyethylene disk technique showed a significantly higher activity at the lower pH.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Animal Models of Chronic Pancreatitis

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Makoto Otsuki ◽  
Mitsuyoshi Yamamoto ◽  
Taizo Yamaguchi
Keyword(s):  
Fluid Flow ◽  
Oleic Acid ◽  
Chronic Pancreatitis ◽  
Animal Models ◽  
Pancreatic Duct ◽  
Sodium Taurocholate ◽  
Pancreatic Injury ◽  
The Other ◽  
Fatty Tissue ◽  
Pancreatic Fluid

Animal models for CP in rats can be classified into 2 groups: one is noninvasive or nonsurgical models and the other is invasive or surgical models. Pancreatic injury induced by repetitive injections of supramaximal stimulatory dose of caerulein (Cn) or by intraductal infusion of sodium taurocholate (NaTc) recovered within 14 days, whereas that caused by repetitive injection of arginine or by intraductal infusion of oleic acid was persistent. However, the destroyed acinar tissues were replaced by fatty tissues without fibrosis. Transient stasis of pancreatic fluid flow by 0.01% agarose and minimum injury of the pancreatic duct by 0.1% NaTc solution induced progressive pancreatic injury although one alone is insufficient to cause persistent pancreatic injury. However, the damaged tissue was replaced by fatty tissue without fibrosis. Continuous pancreatic ductal hypertension (PDH) caused diffuse interlobular and intralobular fibrosis closely resembling human CP.

Differential intestinal absorption of two fatty acid isomers: elaidic and oleic acids

1987 ◽  
Vol 253 (6) ◽  
pp. G751-G759 ◽  
Author(s):  
A. Bernard ◽  
B. Echinard ◽  
H. Carlier
Keyword(s):  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Elaidic Acid ◽  
Lipid Emulsion ◽  
Lymphatic Vessel ◽  
Sodium Taurocholate ◽  
Adult Rats ◽  
High Degree ◽  
Palmitic Acids

The absorption of 14C-labeled oleic acid and 14C-labeled elaidic acid was studied in bile- and pancreatic juice-diverted adult rats. In some cases these acids were compared with 14C-labeled palmitic acid absorption. Sodium taurocholate-emulsified test infusates containing an equimolar mixture of monopalmitin and two fatty acids (oleic and elaidic or palmitic), one of which was 14C labeled, were infused through a duodenal canula. The chyle was collected from the mesenteric lymphatic vessel by plastic tubing. Among the three fatty acids studied, oleic acid exhibited the highest lymphatic recovery rate (43-50%). Elaidic and palmitic acids appeared more slowly and in lesser amounts (10-17%). Simultaneously, the highest amount of chylomicrons was observed when the lipid emulsion contained oleic acid alone; the lowest was observed when elaidic acid was the only unsaturated fatty acid. Experimental data have also shown that compared with elaidic acid, oleic acid is preferentially incorporated into the lymph triglycerides. We can conclude from the data presented that the enterocytic enzymes involved in the absorption of lipids show a high degree of specificity related to the fatty acid isomery, since the absorption of elaidic acid differs markedly from its isomer oleic acid.

scholarly journals Development of Fatty Acid-Producing Corynebacterium glutamicum Strains

2013 ◽  
Vol 79 (21) ◽  
pp. 6776-6783 ◽  
Author(s):  
Seiki Takeno ◽  
Manami Takasaki ◽  
Akinobu Urabayashi ◽  
Akinori Mimura ◽  
Tetsuhiro Muramatsu ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Palmitic Acid ◽  
Acid Production ◽  
Type Strain ◽  
Wild Type Strain ◽  
The Other ◽  
Pcr Analysis ◽  
Wild Type ◽  
Selection Of

ABSTRACTTo date, no information has been made available on the genetic traits that lead to increased carbon flow into the fatty acid biosynthetic pathway ofCorynebacterium glutamicum. To develop basic technologies for engineering, we employed an approach that begins by isolating a fatty acid-secreting mutant without depending on mutagenic treatment. This was followed by genome analysis to characterize its genetic background. The selection of spontaneous mutants resistant to the palmitic acid ester surfactant Tween 40 resulted in the isolation of a desired mutant that produced oleic acid, suggesting that a single mutation would cause increased carbon flow down the pathway and subsequent excretion of the oversupplied fatty acid into the medium. Two additional rounds of selection of spontaneous cerulenin-resistant mutants led to increased production of the fatty acid in a stepwise manner. Whole-genome sequencing of the resulting best strain identified three specific mutations (fasR20,fasA63up, andfasA2623). Allele-specific PCR analysis showed that the mutations arose in that order. Reconstitution experiments with these mutations revealed that onlyfasR20gave rise to oleic acid production in the wild-type strain. The other two mutations contributed to an increase in oleic acid production. Deletion offasRfrom the wild-type strain led to oleic acid production as well. Reverse transcription-quantitative PCR analysis revealed that thefasR20mutation brought about upregulation of thefasAandfasBgenes encoding fatty acid synthases IA and IB, respectively, by 1.31-fold ± 0.11-fold and 1.29-fold ± 0.12-fold, respectively, and of theaccD1gene encoding the β-subunit of acetyl-CoA carboxylase by 3.56-fold ± 0.97-fold. On the other hand, thefasA63upmutation upregulated thefasAgene by 2.67-fold ± 0.16-fold. In flask cultivation with 1% glucose, thefasR20 fasA63upfasA2623triple mutant produced approximately 280 mg of fatty acids/liter, which consisted mainly of oleic acid (208 mg/liter) and palmitic acid (47 mg/liter).

Determination of fatty acid content in some edible insects of Mexico

2016 ◽  
Vol 2 (1) ◽  
pp. 37-42 ◽  
Author(s):  
J.M. Pino Moreno ◽  
A. Ganguly
Keyword(s):  
Oleic Acid ◽  
Fatty Acid ◽  
Acid Content ◽  
Periplaneta Americana ◽  
Fatty Acid Content ◽  
Capric Acid ◽  
Caproic Acid ◽  
Insect Species ◽  
Edible Insects

In the present paper we have determined the fatty acid content of some edible insects of Mexico. A comparative analysis of the insect species studied in this research showed that caproic acid was present in a minimal proportion which ranged between 0.01 for Periplaneta americana (nymphs) and 0.06 (g/100 g, dry basis) for Euschistus strenuus. The highest proportion of caprilic acid (0.09) was found in Tenebrio molitor (adults). Atta sp. had the highest amount of capric acid (0.26). Polistes sp. was found to be rich in lauric acid (0.77) and for myristic acid it had the highest content (5.64). Dactylopius sp. and E. strenuus were rich in palmitic acid (14.89). Euschistus taxcoensis had the highest quantity of palmitoleic acid (12.06). Llaveia axin exhibited the highest quantity of stearic acid (22.75). Polistes sp. was found to be rich in oleic acid (38.28). The highest quantity of linoleic acid was observed in T. molitor (larvae) (10.89), and in L. axin the highest content of linolenic acid (7.82) was obtained. A comparison between the species under the present investigation revealed that, in general, the insects are poor in caproic, caprilic, capric, lauric, myristic, palmitoleic and linolenic acids, because the quantities were either minimal or could not be detected at all. They had moderate quantities of stearic, palmitic and linoleic acids and had high quantities of oleic acid. Finally it was concluded that although a particular insect species is unable to fulfil the total fatty acid need for a human, if consumed in combination they could definitely be able to supply a good amount of this highly valued nutrient.

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