scholarly journals Cellular uptake of retinoic acid in vitro

1980 ◽  
Vol 190 (3) ◽  
pp. 839-842 ◽  
Author(s):  
C K Banerjee ◽  
B P Sani
Keyword(s):  
Retinoic Acid ◽  
Chick Embryo ◽  
Acid Concentration ◽  
Cellular Uptake ◽  
Protein Complex ◽  
Incubation Medium ◽  
Temperature Dependent ◽  
Colon Tumour ◽  
Mouse Colon

Incubation of chick embryo skin and mouse colon tumour 26 with [3H]retinoic acid resulted in the formation of a complex of retinoic acid and its cellular binding protein both in cytosol and in nuclei. Formation of the ligand—protein complex was temperature-dependent and increased with increases in retinoic acid concentration in the incubation medium. About 3—8% of the ligand present in the cytosol was associated with the nuclei.

scholarly journals A new coactivator complex required for retinoic acid-dependent regulation of embryonic symmetry

2016 ◽  
Author(s):  
Goncalo C. Vilhais-Neto ◽  
Marjorie Fournier ◽  
Jean-Luc Plassat ◽  
Mihaela E. Sardiu ◽  
Anita Saraf ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Rna Polymerase Ii ◽  
Protein Complex ◽  
Target Genes ◽  
Bilateral Symmetry ◽  
Molecular Control ◽  
Mouse Mutants ◽  
Proteomic Approach

Bilateral symmetry is a striking feature of the vertebrate body plan organization. Vertebral precursors, called somites, provide one of the best illustrations of embryonic symmetry. Maintenance of somitogenesis symmetry requires Retinoic acid (RA) and its coactivator Rere/Atrophin2. Here, using a proteomic approach we identify a protein complex, containing Wdr5, Hdac1, Hdac2 and Rere (named WHHERE), which regulates RA signalling and controls embryonic symmetry. We demonstrate that Wdr5, Hdac1 and Hdac2 are required for RA signalling in vitro and in vivo. Mouse mutants for Wdr5 and Hdac1 exhibit asymmetrical somite formation characteristic of RA-deficiency. We also identify the Rere-binding histone methyltransferase Ehmt2/G9a, as a RA coactivator controlling somite symmetry. Upon RA treatment, WHHERE and Ehmt2 become enriched at RA target genes to promote RNA Polymerase II recruitment. Our work identifies a novel protein complex linking key epigenetic regulators acting in the molecular control of embryonic bilateral symmetry.

Patterning of motor neurons by retinoic acid in the chick embryo hindbrain in vitro

2003 ◽  
Vol 23 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Sonia Guidato ◽  
Camilla Barrett ◽  
Sarah Guthrie
Keyword(s):  
Retinoic Acid ◽  
Chick Embryo ◽  
Motor Neurons

STUDIES ON THE BINDING OF CORTISOL-4-14C BY HUMAN LEUCOCYTES IN VITRO

1963 ◽  
Vol 42 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Melvin M. Ketchel ◽  
Elaine Garabedian
Keyword(s):  
Methylene Blue ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Linear Relationship ◽  
Salt Solution ◽  
Incubation Medium ◽  
Fold Increase ◽  
Temperature Dependent

ABSTRACT The amount of cortisol-4-14C bound by human leucocytes in a non-protein balanced salt solution was found to have a linear relationship to the concentration of cortisol-4-14C for a given number of leucocytes, and a linear relationship to the number of leucocytes for a given concentration of cortisol-4-14C. The binding was not affected by 10−3 m concentrations of arsenate, cyanide, fluoroacetate, dinitrophenol, fluoride, methylene blue, malonate, hydroxylamine or semicarbazide. The binding of cortisol-4-14C by leucocytes was found to be temperature dependent. At 0° C, no binding of cortisol-4-14C was detected. From 10° to 80°, each 10° rise resulted in an approximately two fold increase in amount of cortisol-4-14C bound, but no further increase occurred between 80° and 100°. Experiments in which leucocytes were exposed to various specific temperatures without cortisol, and then incubated with cortisol-4-14C at 37° revealed that exposure to lower temperatures had no effect on the uptake of cortisol-4-14C at 37°, but that exposure to higher temperatures had increased the binding of cortisol-4-14C at 37°. The addition of either human plasma or human serum albumin to the incubation medium markedly reduced the uptake of cortisol-4-14C by the leucocytes. Approximately 2/3 of the cortisol-4-14C (or metabolite) was removed upon incubation for 30 minutes at 37° C with either Hanks's solution (non-protein), plasma or serum albumin.

EFFECT OF 17α-METHYL-β-NORTESTOSTERONE (SK & F 7690) ON THE BINDING IN VITRO OF 5α-DIHYDROTESTOSTERONE TO MACROMOLECULAR COMPONENTS FROM THE RAT VENTRAL PROSTATE

1971 ◽  
Vol 66 (2) ◽  
pp. 352-356 ◽  
Author(s):  
Kjell J. Tveter
Keyword(s):  
Tissue Culture ◽  
Protein Complex ◽  
Incubation Medium ◽  
Culture Medium ◽  
Tissue Culture Medium ◽  
Male Rats ◽  
Ventral Prostate ◽  
Nuclear Fraction ◽  
Rat Ventral Prostate

ABSTRACT Slices from prostate glands of castrated male rats were incubated with [3H] 5α-dihydrotestosterone in Eagle's tissue culture medium. The labelled androgen was associated with androphilic macromolecules both in the prostatic cytosol and the nuclei. The addition of the anti-androgenic compound, 17α-methyl-β-nortestosterone (SK & F 7690) to the incubation medium inhibited the formation of the nuclear 5α-dihydrotestosterone-protein complex, and markedly reduced the cytosol 5α-dihydrotestosterone-protein complex. Likewise, the uptake of [3H] 5α-dihydrotestosterone by the prostatic nuclear fraction was reduced by about 40%.

Metabolism of thyroid hormones in isolated rat hepatocytes: studies on the influences of carbamazepine and phenytoin

1983 ◽  
Vol 104 (4) ◽  
pp. 479-484 ◽  
Author(s):  
Sylvi Aanderud ◽  
Jarle Aarbakke ◽  
Johan Sundsfjord
Keyword(s):  
Thyroid Hormones ◽  
Cellular Uptake ◽  
Incubation Medium ◽  
Rat Hepatocytes ◽  
Isolated Rat Hepatocytes ◽  
Isolated Rat

Abstract. The in vitro handling of thyroid hormones was studied in isolated rat hepatocytes by measuring 1) the cellular uptake of T4, 2) the conversion of T4 to T3 and 3) the degradation of T4 and T3. The in vitro conversion of T4 to T3 increased significantly by adding ethanol 2% or carbamazepine (CBZ) 400 μm in ethanol 2% to the incubation medium. As there was no difference between ethanol and CBZ/ethanol on the T3 formation, this effect was probably caused by ethanol. The T3 formation was unaffected by phenytoin (PHT) in conc. up to 400 μm, while propylthiouracil (PTU) 100 and 400 μm inhibited the conversion completely. The T4 to T3 conversion in hepatocytes from rats pretreated with CBZ or PHT for 2 weeks was not significantly different from untreated controls. The cellular uptake of T4 was reduced by about 30% in the presence of PHT and unaltered by CBZ and ethanol. The degradation of T4 and T3 was not influenced by the in vitro addition of CBZ or PHT, nor was the degradation of T4 and T3 significantly different from untreated controls in hepatocyte suspensions from CBZ or PHT pretreated rats. Our findings suggest that the handling of thyroid hormones in isolated rat hepatocytes is not influenced by the in vitro or in vivo exposure to CBZ or PHT.

In Vitro Effects of Urokinase — Prevention by Different Inhibitors

1990 ◽  
Vol 64 (03) ◽  
pp. 402-406 ◽  
Author(s):  
M D Oethinger ◽  
E Seifried
Keyword(s):  
In Vitro Study ◽  
Thrombin Time ◽  
Plasma Samples ◽  
Temperature Dependent ◽  
Chloromethyl Ketone ◽  
Control Value ◽  
Dose Time ◽  
In Vitro Effects ◽  
Full Protection

SummaryThe present in vitro study investigated dose-, time- and temperature-dependent effects of two-chain urokinase plasminogen activato(u-PA, urokinase) on normal citrated plasma. When 10 μg/ml u-PA wereadded to pooled normal plasma and incubated for 30 min at an ambient temperature (25° C), α2-antiplas-min decreased to 8% of the control value. Incubation on ice yielded a decrease to 45% of control,whereas α2-antiplasmin was fully consumed at 37° C. Fibrinogen and plasminogen fell to 46% and 39%, respectively, after a 30 min incubation at 25° C. Thrombin time prolonged to 190% of control.Various inhibitors were studied with respect to their suitability and efficacy to prevent these in vitro effects. Aprotinin exhibited a good protective effect on fibrinogen at concentrations exceeding 500 KlU/ml plasma. Its use, however, was limited due to interferences with some haemostatic assays. We could demonstrate that L-Glutamyl-L-Glycyl-L-Arginyl chloromethyl ketone (GGACK) and a specific polyclonal anti-u-PA-antibody (anti-u-PA-IgG) effectively inhibited urokinase-induced plasmin generation without interfering with haemostatic assays. The anti-u-PA-antibody afforded full protection ofα2-antiplasmin at therapeutic levels of u-PA.It is concluded that u-PA in plasma samples from patients during thrombolytic therapy may induce in vitro effects which should be prevented by the use of a suitable inhibitor such as GGACK or specific anti-u-PA-antibody.

ALDOSTERONE STIMULATION IN VITRO

1965 ◽  
Vol 50 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Jürg Müller
Keyword(s):  
Ammonium Chloride ◽  
Human Urine ◽  
Incubation Medium ◽  
The Other ◽  
Ammonium Ions ◽  
Response Curves ◽  
Urine Extract ◽  
Similar Dose ◽  
Aldosterone Production

ABSTRACT An extract of human urine, which was previously shown to stimulate aldosterone production by rat adrenal sections, was further purified. Evidence was obtained that its aldosterone-stimulating effect was due to the presence of ammonium ions. Addition of ammonium chloride and of urine extract to the incubation medium caused identical increases in aldosterone production in vitro. In addition to ammonium ions, rubidium and caesium ions also stimulated aldosterone production up to 250% that of control values without a significant effect on corticosterone production. Similar dose-response curves were obtained when increasing concentrations of potassium, ammonium, rubidium and caesium ions were tested. Aldosterone production was maximal at concentrations of 7 mval/1 and was significantly lower at higher concentrations. When ammonium chloride and ACTH were simultaneously added to the incubation medium, the production of aldosterone and of corticosterone was lower than with ACTH alone. On the other hand, the stimulating activity on aldosterone and corticosterone production by »TPN« (NADP) and glucose-6-phosphate was enhanced by the simultaneous addition of ammonium chloride.

IN VITRO UPTAKE OF TRITIATED OESTRADIOL BY THE ANTERIOR HYPOTHALAMUS AND HYPOPHYSIS OF THE RAT

1970 ◽  
Vol 64 (4) ◽  
pp. 687-695 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Incubation Medium ◽  
Posterior Hypothalamus ◽  
Anterior Hypothalamus ◽  
Ovariectomized Rats ◽  
Free Medium ◽  
Cortex Cerebri ◽  
Anterior Hypophysis ◽  
In Vitro Uptake

ABSTRACT The anterior, middle, and posterior hypothalamus, the cortex cerebri, the anterior hypophysis as well as the diaphragm of adult ovariectomized rats were incubated in vitro with tritiated 17β-oestradiol. The uptake of tritiated oestradiol was differentially distributed intracerebrally with higher accumulation in the anterior hypothalamus and the hypophysis. Lowering the temperature of the incubation medium caused a reduction in the uptake of radioactivity by the anterior hypothalamus as compared to that found in other brain tissues. Tritiated oestradiol taken up in vitro by the anterior hypothalamus and the hypophysis tended to be retained after further incubation in a steroid-free medium. The addition of non-radioactive 17β-oestradiol to the medium inhibited the uptake of tritiated oestradiol by these tissues. Moreover, pretreatment with non-radioactive 17β-oestradiol in vivo prevented the preferential accumulation of tritiated oestradiol in vitro in the anterior hypothalamus and the hypophysis. These results indicate that oestradiol is preferentially taken up in vitro by the anterior hypothalamus and the hypophysis of the rat.

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