Transport of vitamin A in vitro across normal isolated rat intestine and intestine subjected to ‘partial’ resection

1959 ◽  
Vol 197 (6) ◽  
pp. 1333-1336 ◽  
Author(s):  
M. R. Loran ◽  
T. L. Althausen
Keyword(s):  
Vitamin A ◽  
Tween 80 ◽  
Iodoacetic Acid ◽  
Anaerobic Conditions ◽  
Sorbitan Monooleate ◽  
Aerobic Conditions ◽  
Total Transport ◽  
Normal Intestine ◽  
Resected Intestine

The transport of vitamin A across normal and resected intestine was studied in vitro by the method of Darlington and Quastel. The results showed that under aerobic conditions the rate of transport of vitamin A across normal and resected intestine was identical. In contrast, under anaerobic conditions transport was reduced 50% for resected intestine and totally inhibited for control intestine. These results were duplicated under aerobic conditions when 2, 4, dinitrophenol was added to the mucosal solution. Thus for the control intestine, transport is entirely dependent on DNP-sensitive phosphorylation mechanisms which require a wetting agent (polyoxyethylene sorbitan monooleate, ‘Tween 80’) as a solubilizer on the serosal side for the transport of vitamin A across the intestine. The DNP-insensitive mechanisms responsible for 50% of the total transport across the resected intestine were inhibited by iodoacetic acid and sodium fluoride. Chromatographic analysis of intestinal homogenates and mucosal solution at the end of the perfusion demonstrated that vitamin A palmitate is converted to the alcohol either in the lumen or on the surface of the epithelial cells and is then re-esterified in the intestinal mucosa. Transport of this vitamin is via ‘active’ energy-requiring mechanisms. In the normal intestine energy is supplied by oxidative phosphorylation, and in the resected intestine by oxidative as well as anaerobic glycolytic phosphorylation.

METABOLISM OF RAM TESTICULAR SPERMATOZOA IN THE PRESENCE OF TESTOSTERONE AND RELATED STEROIDS

1970 ◽  
Vol 65 (3) ◽  
pp. 565-576 ◽  
Author(s):  
J. K. Voglmayr ◽  
R. N. Murdoch ◽  
I. G. White
Keyword(s):  
Aerobic Glycolysis ◽  
Rete Testis ◽  
Glycolytic Metabolism ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Testicular Spermatozoa ◽  
Almost All ◽  
Oxidation Of Glucose

ABSTRACT The effects of testosterone* and related steroids on the oxidative and glycolytic metabolism of freshly collected ram testicular spermatozoa and of spermatozoa stored under air in rete testis fluid for 3 days at 3°C have been studied. When freshly collected testicular spermatozoa were incubated with glucose under aerobic conditions only a small proportion of the utilized glucose could be accounted for as lactate. The addition of a number of steroids, including testosterone, androstanedione, 5β-androstanedione, androsterone, epiandrosterone and 5β-androsterone, greatly increased aerobic glycolysis, the oxidation of the substrate and the proportion of the utilized substrate converted to lactic acid. After 3 days storage at 3°C, testicular spermatozoa respired at a greater rate than spermatozoa freshly collected from the testes. Although the stimulating effect of steroids on aerobic glycolysis increased after storage, they depressed rather than stimulated the oxidation of glucose by stored testicular spermatozoa. With the exception of androstanedione, which slightly stimulated glycolysis, storage of testicular spermatozoa for 3 days in the presence of steroids did not significantly influence their subsequent metabolism when washed free of the steroids. Both freshly collected and stored ram testicular spermatozoa displayed a marked Pasteur effect, and utilized more glucose and produced more lactate under anaerobic than under aerobic conditions. In the absence of oxygen the steroids did not stimulate glycolysis to any extent. However, epiandrosterone depressed the glycolysis of freshly collected spermatozoa under anaerobic conditions and after storage, 5β-androsterone had a similar effect. Androstanedione, 5β-androstanedione, epiandrosterone and 5β-androsterone were the most effective steroids in altering the metabolism of testicular spermatozoa and, under almost all conditions of incubation, depressed the synthesis of amino acids from glucose. The results suggest that the effects of testosterone and related steroids in vitro may depend on the age of the spermatozoa after their release from the Sertoli cells; the steroid effects may have important consequences in vivo in relation to sperm maturation.

The energy metabolism of adult Haemonchus contortus, in vitro

Parasitology ◽  
1978 ◽  
Vol 77 (3) ◽  
pp. 255-271 ◽  
Author(s):  
P. F. V. Ward ◽  
N. S. Huskisson
Keyword(s):  
Energy Metabolism ◽  
Haemonchus Contortus ◽  
Aerobic Incubation ◽  
Anaerobic Conditions ◽  
Physically Active ◽  
Aerobic Conditions ◽  
Aerobic And Anaerobic ◽  
Aerobic And Anaerobic Conditions

SummaryA comparison was made of the major excretory products when adult Haemonchus contortus worms were incubated with D-[U-14C]glucose under aerobic and anaerobic conditions. Catabolites measured were propan-1-ol, acetate, n-propionate and CO2 and the only major difference was that nearly twice as much CO2 both in terms of quantity and radioactivity was excreted under aerobic than anaerobic conditions. The worms were also much more physically active under aerobic conditions. When worms were incubated under aerobic conditions with increasing amounts of fluoroacetate their CO2 production was progressively reduced to the anaerobic level. Their movement and their ability to clump together was also progressively reduced. After aerobic incubation with fluoroacetate and D-[U-14C]g1ucose the quantity and radioactivity of citrate within worms increased greatly. When worms were similarly incubated anaerobically no increase in citrate occurred, no radioactivity was associated with the citrate and the worms appeared physically unaffected. When worms were incubated aerobically with fluoro[1-14C]acetate they produced radioactive fluorocitrate.

In vitro germination and pollen tube growth of maize (Zea mays) pollen. IX. Pollen source genotype and nonionic surfactant interactions

1980 ◽  
Vol 58 (5) ◽  
pp. 557-561 ◽  
Author(s):  
P. L. Pfahler ◽  
H. F. Linskens ◽  
M. Wilcox
Keyword(s):  
Pollen Tube ◽  
Calcium Nitrate ◽  
Pollen Grains ◽  
Tween 80 ◽  
Tube Length ◽  
In Vitro Germination ◽  
Sorbitan Monooleate ◽  
Germination Characteristics ◽  
Surfactant Effects

Because of their structure and active metabolic state, pollen grains are vulnerable to any agent in the in vitro germination medium. Surfactants are used in biological systems to reduce surface tension but are also known to produce subtle biochemical effects. This study investigated the effect of three nonionic surfactants on the germination characteristics of pollen grains from three pollen source genotypes. Pollen grains from three single cross hybrids (Wf9 × H55, K64 × K55, Ky228 × Ky226) were cultured on an artificial medium (15% sucrose, 0.6% bacto-agar, 0.03% calcium nitrate, 0.01% boric acid) supplemented with all possible combinations of three concentrations (10, 100, 1000 ppm, v/v) of the following surfactants: (i) Tween 80 (polyoxyethylene sorbitan monooleate); (ii) X-114 (alkyl phenoxypolyethoxy ethanol); and (iii) commercial sticker spreader (alkyl olefin aromatic polymers). A control containing no supplement was included. Over all genotypes, increasing concentrations of Tween 80 had the least effect on the germination characteristics measured (germination and ruptured percent, pollen tube length at 1, 2, and 3 h after inoculation) and X-114 had the greatest effect with no germination found above 10 ppm. For most of the germination characteristics, highly significant pollen source genotype X concentration interactions were found for each surfactant. The direction and magnitude of the surfactant effects depended on the surfactant, its concentration, the germination characteristic involved, and the pollen source genotype.

Lactate distribution in culture medium of human myometrial biopsies incubated under different conditions

2009 ◽  
Vol 297 (6) ◽  
pp. E1414-E1419 ◽  
Author(s):  
Helena Åkerud ◽  
Gunnar Ronquist ◽  
Eva Wiberg-Itzel
Keyword(s):  
Amniotic Fluid ◽  
Elective Caesarean Section ◽  
Anaerobic Conditions ◽  
Extracellular Medium ◽  
Aerobic Conditions ◽  
Myometrial Cells ◽  
Labor Dystocia ◽  
Production And Distribution ◽  
Membrane Bound

It is generally believed that a relationship exists between muscle fatigue and intracellular accumulation of lactate. This reasoning is relevant to obstetrical issues. Myocytes in uterus work together during labor, and the contractions need to be strong and synchronized for a child to be delivered. At labor dystocia, the progress of labor becomes slow or arrested after a normal beginning. It has been described that, during labor dystocia, when the force of the contractions is low, the uterus is under hypoxia, and anaerobic conditions with high levels of lactate in amniotic fluid dominate. The purpose of this study was to examine whether myometrial cells are involved in the production of lactate in amniotic fluid and whether there are differences in production and distribution of lactate in cells incubated under aerobic and anaerobic conditions. We also wanted to elucidate the involvement of specific membrane-bound lactate carriers. Women undergoing elective caesarean section were included. Myometrial biopsies from uteri were collected and subjected to either immunohistochemistry to identify lactate carriers or in vitro experiments to analyze production of lactate. The presence of lactate carriers named monocarboxylate transporters 1 and 4 was verified. Myometrial cells produced lactate extracellularly, and the lactate carriers operated differently under anaerobic and aerobic conditions; while being mainly unidirectional under anaerobic conditions, they became bidirectional under aerobic conditions. Human myometrial cells produced and delivered lactate to the extracellular medium under both anaerobic and aerobic conditions. The delivery was mediated by lactate carriers.

The metabolism of glucose and pyruvate in rat retina

1962 ◽  
Vol 156 (963) ◽  
pp. 139-143 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Lactic Acid ◽  
Quantitative Data ◽  
Lactate Production ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Rat Retina ◽  
Adult Rat ◽  
Total Glucose

The metabolism of [U- 14 C]glucose and [3- 14 C]pyruvate in the adult rat retina is described. In vitro under aerobic conditions, in either phosphate or bicarbonate medium, glucose was converted into lactate, carbon dioxide, glutamate, γ -aminobutyrate, aspartate, glutamine and alanine. Under anaerobic conditions, total glucose metabolized was reduced to 60 to 70% of that under aerobic conditions, lactic acid being the only metabolic product detected. Under aerobic conditions [3- 14 C]pyruvate was converted by the retina into the same metabolites as was glucose. The quantitative data for oxygen uptake and 14 CO 2 formation were similar to those obtained with glucose as substrate; lactate production was lower and amino acid formation higher.

scholarly journals Use of Tween 40 and Tween 80 to deliver a mixture of phytochemicals to human colonic adenocarcinoma cell (CaCo-2) monolayers

2004 ◽  
Vol 91 (5) ◽  
pp. 757-764 ◽  
Author(s):  
Sinead M. O'Sullivan ◽  
Julie A. Woods ◽  
Nora M. O'Brien
Keyword(s):  
Synergistic Effects ◽  
Tween 80 ◽  
Colonic Adenocarcinoma ◽  
Sorbitan Monooleate ◽  
Lipophilic Compounds ◽  
Cells In Culture ◽  
Adenocarcinoma Cells ◽  
Human Colonic Adenocarcinoma Cell ◽  
Tween 40

Epidemiological evidence suggests that dietary intake of carotenoids and tocopherols may influence the risk of certain chronic diseases, such as cancer and CVD. In vitro studies investigating the synergistic effects of mixtures of carotenoids and tocopherols have been hindered due to the difficulty of solubilising these lipophilic compounds. The objective of the present study was to develop a system for delivering tocopherols and carotenoids simultaneously to cells in culture. Differentiated human colonic adenocarcinoma cells (CaCo-2) were incubated with a mixture of these phytochemicals for 24 h. The phytochemical mixture included carotenoids (astaxanthin, canthaxanthin, lutein, lycopene, α-carotene, β-carotene) and tocopherols (α-tocopherol and γ-tocopherol). The emulsifiers polyoxyethylene sorbitan monopalmitate (Tween 40) and polyoxyethylene sorbitan monooleate (Tween 80) were employed as the delivery vehicles, and were compared with tetrahydrofuran (THF). Each vehicle was added at a maximum concentration of 1 ml/l. No toxic effects to the CaCo-2 cells were noted when Tween 40 or Tween 80 were used. Both Tween 40 and Tween 80 resulted in greater solubility of the mixture and delivered substantially more carotenoids and tocopherols to the cells than THF. In particular, lycopene was detected within the cells when Tween 40 and Tween 80 were employed, whereas it was below the limits of detection by HPLC when THF was used as the delivery vehicle. The phytochemicals were retained within the cells for 24 h after supplementation. Tween 40 and Tween 80 have potential as simple, rapid and non-toxic methods for delivering mixtures of carotenoids and tocopherols to cells in culture.

Incomplete free fatty acid oxidation by ascites tumor cells under low oxygen tension

1983 ◽  
Vol 244 (1) ◽  
pp. R84-R92
Author(s):  
M. Ookhtens ◽  
N. Baker
Keyword(s):  
Fatty Acid ◽  
Maximum Rate ◽  
Acid Oxidation ◽  
Ascites Tumor ◽  
Low Oxygen ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Oxidation Rates

We tried to understand why our earlier estimates of fatty acid (FA) oxidation rates under the nearly anaerobic state of the Ehrlich ascites tumor (EAT) in vivo were even greater than those found in vitro under aerobic conditions. Using tracers [1–14C]linoleate, [1–14C]-, and [9,10–3H]palmitate, and NaH14CO3, we estimated essential and nonessential FA oxidation rates to CO2 + H2O by EAT in living mice and in vitro under aerobic and anaerobic conditions. Sequestration of intraperitoneally (ip)-injected 14C-FFA allowed a selective labeling of the tumor versus the host; thus, breath 14CO2 could be used to estimate the maximum rate of FA oxidation in vivo by the tumor. Initially, we measured breath 14CO2 following NaH14CO3 injections and developed a multicompartmental model to simulate the tumor-host HCO-3-CO2 system. This model was integrated with our earlier model for tumor FA turnover. The integrated model was fitted to breath 14CO2 data from mice injected ip with 14C-FFA to compute tumor FA oxidation rates. Both essential and nonessential FA were oxidized to CO2 at similar rates. The maximum rate of total FA oxidation to CO2 was 5–6 nmol FA X min-1 X 7-ml tumor-1, about 5–10 times lower than all previous estimates obtained in vitro and in vivo. To resolve this dilemma we used doubly labeled [1–14C; 9,10–3H]palmitate and found that under aerobic conditions, in vitro, EAT formed 3H2O and 14CO2 at nearly equal rates. These rates were suppressed markedly but unequally at low PO2. Anaerobic suppression of 14CO2 formation greatly exceeded that of 3H2O formation. As a result 3H2O/14CO2 reached a value of congruent to 10 at low PO2. Our data indicate that under the nearly anaerobic conditions of a growing EAT in vivo, the partial beta-oxidation of FA to 2C + H2O takes place at a 5 to 10 times faster rate than the complete oxidation of FA to CO2 + H2O. This finding can account for earlier apparent inconsistencies in the literature, since aerobic studies of 14C-FA oxidation to 14CO2 in vitro and of 3H-FA oxidation to 3H2O under nearly anaerobic conditions would both overestimate greatly the rate of FA oxidation to CO2 by EAT in vivo.

Effects of different vehiculization strategies for the allium derivative propyl propane thiosulfonate during dynamic simulation of the pig gastrointestinal tract

2019 ◽  
Vol 99 (2) ◽  
pp. 244-253 ◽  
Author(s):  
Paloma Abad ◽  
Natalia Arroyo-Manzanares ◽  
E. Rivas-Montoya ◽  
J.M. Ochando-Pulido ◽  
Enrique Guillamon ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Gastrointestinal Tract ◽  
Plug Flow ◽  
Tubular Reactor ◽  
Tween 80 ◽  
Continuous Stirred Tank Reactor ◽  
Sorbitan Monooleate ◽  
In Series ◽  
The One

This paper evaluates the bioavailability of allium derivative propyl propane thiosulfonate (PTSO) in the pig gastrointestinal tract by means of an in vitro dynamic gastrointestinal tract simulator system (GITSS). The GITSS is based on a membrane bioreactor comprising a continuous stirred-tank reactor connected in series to a continuous plug-flow tubular reactor. Bioavailability values have been evaluated for different vehiculization strategies, including mere carriers such as polyethylene glycol sorbitan monooleate (a nonionic surfactant also known as Tween 80) and encapsulation matrices (β-cyclodextrin vs. mono- and di-glycerides of edible fatty acids mixed with hydrogenated sunflower oil) and compared with the absorption of free PTSO. The net absorbed amount of PTSO in the GITSS when Tween 80 was used as a carrier was over 3.5 times higher than the one for free PTSO. Neither the encapsulated PTSO in β-cyclodextrin nor by means of mono- and di-glycerides of fatty acids plus a vegetable oil succeeded to improve absorption values for free PTSO. These promising results indicate that Tween 80 provides an interesting and high resistance to the PTSO molecule against the simulated digestive conditions in the stomach, and thus it enables favorably the subsequent absorption process of PTSO along the intestine.

An in vitro model for investigation of vitamin A effects on wound healing

2021 ◽  
pp. 1-6
Author(s):  
Hoda Keshmiri Neghab ◽  
Mohammad Hasan Soheilifar ◽  
Gholamreza Esmaeeli Djavid
Keyword(s):  
Wound Healing ◽  
Endothelial Cell ◽  
Vitamin A ◽  
In Vitro Model ◽  
Cellular Proliferation ◽  
Endothelial Cell Migration ◽  
Normal Fibroblast ◽  
Anti Inflammatory ◽  
Vitro Model

Abstract. Wound healing consists of a series of highly orderly overlapping processes characterized by hemostasis, inflammation, proliferation, and remodeling. Prolongation or interruption in each phase can lead to delayed wound healing or a non-healing chronic wound. Vitamin A is a crucial nutrient that is most beneficial for the health of the skin. The present study was undertaken to determine the effect of vitamin A on regeneration, angiogenesis, and inflammation characteristics in an in vitro model system during wound healing. For this purpose, mouse skin normal fibroblast (L929), human umbilical vein endothelial cell (HUVEC), and monocyte/macrophage-like cell line (RAW 264.7) were considered to evaluate proliferation, angiogenesis, and anti-inflammatory responses, respectively. Vitamin A (0.1–5 μM) increased cellular proliferation of L929 and HUVEC (p < 0.05). Similarly, it stimulated angiogenesis by promoting endothelial cell migration up to approximately 4 fold and interestingly tube formation up to 8.5 fold (p < 0.01). Furthermore, vitamin A treatment was shown to decrease the level of nitric oxide production in a dose-dependent effect (p < 0.05), exhibiting the anti-inflammatory property of vitamin A in accelerating wound healing. These results may reveal the therapeutic potential of vitamin A in diabetic wound healing by stimulating regeneration, angiogenesis, and anti-inflammation responses.

The Reaction of Thiol Compounds with the Vitamin-K Dependent Clotting Factors

1969 ◽  
Vol 21 (03) ◽  
pp. 573-579 ◽  
Author(s):  
P Fantl
Keyword(s):  
Prothrombin Time ◽  
Vitamin K ◽  
Anaerobic Conditions ◽  
Clotting Factors ◽  
Thiol Compounds ◽  
Aerobic Conditions ◽  
One Stage ◽  
Factor Ii ◽  
Ph Dependent ◽  
The One

SummaryTreatment of human and dog oxalated plasma with 0.2 to 1.0 × 10−1 M 2.3-dithiopropanol (BAL) or dithiothreitol (DTT) at 2–4° C for 30 min results in the reduction of the vitamin-K dependent clotting factors II, VII, IX and X to the respective-SH derivatives. The reaction is pH dependent. Under aerobic conditions the delayed one stage prothrombin time can be partly reversed. Under anaerobic conditions a gradual prolongation of the one stage prothrombin time occurs without reversal.In very diluted plasma treated with the dithiols, prothrombin can be converted into thrombin if serum as source of active factors VII and X is added. In contrast SH factors VII, IX and X are inactive in the specific tests. Reoxidation to active factors II, VII, IX and X takes place during adsorption and elution of the SH derivatives. The experiments have indicated that not only factor II but also factors VII, IX and X have active-S-S-centres.

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