Retinol lymphatic and portal transport: influence of pH, bile, and fatty acids

1980 ◽  
Vol 239 (3) ◽  
pp. G210-G214 ◽  
Author(s):  
D. Hollander
Keyword(s):  
Fatty Acids ◽  
Micellar Solution ◽  
Octanoic Acid ◽  
Unsaturated Fatty Acids ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Arachidonic Acids ◽  
Influence Of Ph ◽  
Long Chain

Absorption of [3H]retinol into lymph and bile was studied in unanesthetized rats with cannulated thoracic and common bile ducts. Retinol in a micellar solution was infused into the duodenum. Absorption of retinol into lymph increased when the infusate's taurocholate concentration was increased to 10 mM, when the hydrogen ion concentration was increased, or when octanoic acid was added to the infusate. Absorption of retinol into lymph decreased when the taurocholate concentration was decreased to 5 mM or when long-chain unsaturated fatty acids or retinoic acid were added to the duodenal infusate. Retinol absorption into bile increased following additions of linoleic and arachidonic acids to the infusate, but absorption did not change following modifications of the infusate's taurocholate concentration or pH. These experiments, which demonstrate that intraluminal factors do modify the extrusion of retinol into bile and lymph, enhance our overall understanding of the process of absorption of this lipid nutrient.

scholarly journals Interfacial tension and hydrogen-ion concentration

1931 ◽  
Vol 109 (760) ◽  
pp. 88-90 ◽  
Keyword(s):  
Interfacial Tension ◽  
Carboxylic Acids ◽  
Capric Acid ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Dissociation Curve ◽  
Weak Base ◽  
Hydrogen Ion Concentration ◽  
Long Chain ◽  
Hydrion Concentration

(1) Long chain carboxylic acids dissolved in benzene show regular changes in interfacial tension against aqueous "buffered" solutions as the hydrion concentration of these is altered. A fall in interfacial tension starts at p h 5·5 and extends over the range of 4·0 p h 9·3 approximately, tending to vanish at this point. The curve is not identical with a dissociation curve, though it extends over the same range of p h . For a given p h the results are identical for phosphate and glycine "buffered" solutions, and for all acids investigated, except capric acid(C 10 ), which shows an abnormality for phosphate. (2) Hexadecylamine shows similar changes, in the opposite sense between approximately the same p h range, which follow the dissociation curve of a weak base rather closely

scholarly journals STIMULATION OF FUNDULUS BY HYDROCHLORIC AND FATTY ACIDS IN FRESH WATER, AND BY FATTY ACIDS, MINERAL ACIDS, AND THE SODIUM SALTS OF MINERAL ACIDS IN SEA WATER

1934 ◽  
Vol 17 (6) ◽  
pp. 803-816 ◽  
Author(s):  
J. B. Allison ◽  
William H. Cole
Keyword(s):  
Fatty Acids ◽  
Fresh Water ◽  
Sea Water ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Sodium Salts ◽  
Mineral Acids ◽  
Effective Hydrogen ◽  
Stimulation Of

1. Fundulus heteroclitus was found to be a reliable experimental animal for studies on chemical stimulation in either fresh or sea water. 2. The response of Fundulus to hydrochloric, acetic, propionic, butyric, valeric, and caproic acids was determined in fresh water, while the same acids plus sulfuric and nitric, as well as the sodium salts of the mineral acids, were tested in sea water. 3. Stimulation of Fundulus by hydrochloric acid in fresh water is correlated with the effective hydrogen ion concentration. Stimulation by the n-aliphatic acids in the same environment is correlated with two factors, the effective hydrogen ion concentration and the potential of the non-polar group in the molecule. However, as the number of CH2 groups increases the stimulating effect increases by smaller and smaller amounts, approaching a maximum value. 4. Stimulation of Fundulus by hydrochloric, sulfuric, and nitric acids in sea water is correlated with the forces of primary valence which in turn are correlated with the change in hydrogen ion concentration of the sea water. The n-aliphatic acids increase in stimulating efficiency in sea water as the length of the carbon chain increases, but a limiting value is not reached as soon as in fresh water. 5. Only a slight difference in stimulation by hydrochloric acid is found in sea water and in fresh water. However, there is a significant difference in stimulation by the fatty acids in fresh and in sea water, which is partly explained by the different buffering capacities of the two media. It is to be noted that in the same environment two different fish, Fundulus and Eupomotis, give different results, while the same fish (Fundulus) in two different environments responds similarly to mineral acids but differently to fatty acids. These results illustrate that stimulation is a function of the interaction between environment and receptors, and that each is important in determining the response. 6. Stimulation by sodium chloride, nitrate, and sulfate is correlated with equivalent concentrations of the salts added to sea water, or with the forces of primary valence. Although the threshold for stimulation by the salts is considerably higher than for the acids, the efficiency of stimulation by the salts is greater.

Nutritional studies of a flagellated protozoan Hexamita inflata from the Canadian oyster, Crassostrea virginica

1968 ◽  
Vol 14 (8) ◽  
pp. 817-821 ◽  
Author(s):  
B. T. Khouw ◽  
H. D. McCurdy Jr.
Keyword(s):  
Unsaturated Fatty Acids ◽  
Egg Yolk ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration ◽  
Wide Range ◽  
Simple Medium ◽  
Nutritional Studies ◽  
Vitamin Mixture ◽  
Anaerobic Environment

The physical and nutritional requirements for growth of Hexamita inflata have been studied in axenic cultures. The flagellate was capable of growing over a wide range of temperature (5 °C to 25 °C), of hydrogen ion concentration (pH 4.5 to 8.5), and of salinity (3 to 28‰); and required a reducing or anaerobic environment. The requirement of an egg-yolk suspension for growth was partially satisfied by unsaturated fatty acids. Attempts to replace the peptone by mixtures of amino acids were not successful. A simple medium containing a vitamin mixture, linoleic acid, glucose, cysteine, peptone, and salt has been formulated.

INFLUENCE OF pH AND TEMPERATURE ON MYOSIN INACTIVATION

1961 ◽  
Vol 39 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Gérard E. Pelletier ◽  
Ludovic Ouellet
Keyword(s):  
Structural Changes ◽  
Electrostatic Charge ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Kcal Mole ◽  
Order Process ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
Inactivation Process ◽  
Influence Of Ph

The inactivation of myosin adenosine triphosphatase activity was studied in 0.6 M potassium chloride solution at pH ranging from 7.0 to 10.8 and for 5 °C to 40 °C. The inactivation is a first-order process with respect to time and 0.6th order with respect to the concentration of protein. The rate of inactivation is independent of the pH for pH 7.0 to pH 8.5 at 35 °C and increases rapidly with pH at higher pH. At 12 °C, close to pH 10.4, the rate is inversely proportional to the 4.5th power of the hydrogen ion concentration. The energies of activation are 56 kcal mole−1 at pH 8.0 and 58 kcal mole−1 at pH 10.5. A discussion of the data stresses the importance of structural changes and indicates a possible role for the electrostatic charge in the inactivation process.

DEVELOPMENT OF AN EXPERIMENTAL MODEL OF AVITAMINOSIS F

2020 ◽  
Vol 20 (2) ◽  
pp. 38-40
Author(s):  
A. Levitsky ◽  
A. Lapinska ◽  
I. Selivanskaya
Keyword(s):  
Fatty Acids ◽  
Experimental Model ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Coconut Oil ◽  
The Body ◽  
Regulatory Function ◽  
Omega 3 ◽  
White Rats ◽  
Arachidonic Acids

The article analyzes the role of essential polyunsaturated fatty acids (PUFA), especially omega-3 series in humans and animals. The biosynthesis of essential PUFA in humans and animals is very limited, so they must be consumed with food (feed). Тhe ratio of omega-3 and omega-6 PUFA is very important. Biomembranes of animal cells contain about 30% PUFA with a ratio of ω-6/ ω-3 1-2. As this ratio increases, the physicochemical properties of biomembranes and the functional activity of their receptors change. The regulatory function of essential PUFA is that in the body under the action of oxygenase enzymes (cyclooxygenase, lipoxygenase) are formed extremely active hormone-like substances (eicosanoids and docosanoids), which affect a number of physiological processes: inflammation, immunity, metabolism. Moreover, ω-6 PUFA form eicosanoids, which have pro-inflammatory, immunosuppressive properties, and ω-3 PUFAs form eicosanoids and docosanoids, which have anti-inflammatory and immunostimulatory properties. Deficiency of essential PUFA, and especially ω-3 PUFA, leads to impaired development of the body and its state of health, which are manifestations of avitaminosis F. Prevention and treatment of avitaminosis F is carried out with drugs that contain PUFA. To create new, more effective vitamin F preparations, it is necessary to reproduce the model of vitamin F deficiency. An experimental model of vitamin F deficiency in white rats kept on a fat –free diet with the addition of coconut oil, which is almost completely free of unsaturated fatty acids, and saturated fatty acids make up almost 99 % of all fatty acids was developed. The total content of ω-6 PUFA (sum of linoleic and arachidonic acids), the content of ω-3 PUFA (α-linolenic, eicosapentaenoic and docosahexaenoic acids) in neutral lipids (triglycerides and cholesterol esters) defined. Тhe content of ω-6 PUFA under the influence of coconut oil decreased by 3.3 times, and the content of ω-3 PUFA - by 7.5 times. Тhe influence of coconut oil, the content of ω-6 PUFA decreased by 2.1 times, and the content of ω-3 PUFA - by 2.8 times. The most strongly reduces the content of ω-3 PUFA, namely eicosapentaenoic, coconut oil, starting from 5 %. Consumption of FFD with a content of 15 % coconut oil reduces the content of eicosapentaenoic acid to zero, ie we have an absolute deficiency of one of the most important essential PUFAs, which determined the presence of vitamin F deficiency.

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