Deoxycholate radioactive

Figure 6. Elution profile of protein, radioactivity, and thiocyanate from a Sepha-dex G-25 column of reconstituted monooxygenase system from rat liver that had been incubated with [ 5] parathion. The 5-mL incubation mixture contained 20 nmol Cytochrome P-450 (specific activity 16.4 nmol/mg protein), 5 units NADPH-Cytochrome c reductase, 600 fig dilauroyl L-3-phosphatidylchoUne, 600 fig sodium deoxycholate, and 1 X IO M p 5] parathion. The remainder of the incubation mixture is described in Figure 4. The incubation time was 5 min. One-milliliter fractions were collected. The radioactivity (x) represents cpm/0.1 mL. The OOggo (o) was measured on each 1-mL fraction (20).

Worms washed to remove free label. Homogenised in buffer + enzyme inhibitors + Na deoxycholate. Extracted at 4°C and centrifuged. Radioactivity counted... 

Experimentally, C14-aminoacyl sRNA was incubated with rat liver microsomes or ribosomes, GTP, various fractions obtained from the nonparticulate portion of rat liver homogenates, and buffered salt-sucrose medium in a total volume of approximately 2 ml. (6-10). The C14-aminoacyl sRNA was prepared by the phenol-extraction procedure from the pH 5 amino acid-activating enzymes, fraction of rat liver after incubation with C14-L-amino acids (9, 13). C14-leucyl sRNA (approximately 1000 c.p.m.), having a specific radioactivity of approximately 55,000 c.p.m. per mg. of RNA, and containing a complement of endogenous, unlabeled, bound amino acids, was used in most of these studies. The microsomes were sedimented from the post-mitochondrial supernatant at 104,000 x g (10) and the ribosomes were prepared from them by extraction with deoxycholate (16). 

Fig. 1. Time course of ADP-ribosylation of Rho. 1 ng of recombinant GST-Rho (fusion protein) was incubated with 20 (iM of [ P]-NAD and 3ng of the wild type ( ) or the E173Q (o) mutant of C3 exoenzyme in a total volume of 50 nl of ADP-ribosylation buffer, as described in the text, at 30°C for times indicated. The reaction was terminated by the addition of trichloroacetic acid and Na deoxycholate. After centrifugation, the pellets were subjected to SDS polyacrylamide gel electrophoresis, followed by staining with Coomassie Brilliant Blue and autoradiography. P-ADP-ribosylation of Rho was quantified by cutting out the radiolabeled GST-Rho bands and determining their radioactivities. The relative ADP-ribosylation was expressed as the ratio of the P incorporation into GST-Rho at each point to the maximal P incorporation by the wild type C3 exoenzyme... 

Fig. 4. Composition of residual C radioactivity in duodenal fluid obtained 24 hr after intravenous injection of either taurochoIate- C or glycochoIate- C to patients with disorders of the distal small bowel (see Table I). Data are expressed in terms of percentage of radioactivity contributed by each bile salt fraction to the total recoverable radioactivity. GDC, glycodeoxycholate GC, glycocholate TDC, tauro-deoxycholate TC, taurocholate. In part from Heaton et al. (3).

Studies with radioactive glycocholate or taurocholate demonstrated a virtual absence of the enterohepatic circulation of bile acids in patients with jejunotransversocolostomy (77). The small amount of absorbed bile acids contained some deconjugated cholate and deoxycholate (which had been reconjugated in the liver), indicating a rapid bacterial action during an apparently fast intestinal passage. Under these conditions, steatorrhea is apparently not solely due to bile salt deficiency induced impairment of micelle formation, but reduced absorptive area may play an important contributory role. No direct measurement of bile acid synthesis by fecal determination has been performed in this condition. 

The demonstration by Bergstrom et al. (4,5) in 1953 of the conversion of deoxycholic acid to taurocholic acid in the rat in vivo and by rat liver slices paved the way for studies on 7a-hydroxylation and conjugation of bile acids. The early work on the synthesis of bile acid conjugates in vitro utilized slices or homogenates of rat and human liver, and the enzymatic reaction was followed by the incorporation of radioactivity from carboxyl- C-labeled bile acids into the corresponding taurine and glycine conjugates (6,7). The... 

The RC was first identified as a membrane-associated structure in the cytoplasm of poliovirus-infected cells. Treatment with deoxycholate liberated a fast-sedimentation component (average 250 S), which contained most of the label after short pulses with radioactive uridine. Ribosomes were not associated with the complex, as EDTA did not modify its sedimentation behaviour (52). 

Partial separations of the substituted methyl allocholanoates have now been achieved by crystallization. Kallner (41, 45) has reported the removal of 82% of the radioactivity after three crystallizations of a mixture of methyl allolithocholate- H and methyl lithocholate 90% of the tritium was removed by several crystallizations of a mixture of methyl lithocholate- H and allolithocholate. Similarly, more than 90% of the radioactivity was removed from a mixture of methyl deoxycholate- H and allodeoxycholate after three crystallizations from aqueous acetic acid or aqueous methanol. Methyl 3/3,12a-dihydroxy-5 -cholanate was separated from methyl deoxy-cholate by crystallization from aqueous methanol. Thomas et al. (46) reported the separation of 3a,6/3-dihydroxy-5 - or 3a,6a-dihydroxy-5 -cholanoic acid from 3a,6/3-dihydroxy-5 -cholanoic acid by crystallization from aqueous acetone or a mixture of methanol, ether, and hexane. 

Heptakls-(, 6-dl-0-methyl)-beta-cyclodextrin (DIMES) (Chinoin Pharm.-Chem. Works) At least 90% of the substance corresponds to the above mentioned chemical name. The remaining 10% is a mixture of different, very closely related methylated derivatives. The heavy metal content is less than 10 ppm, the organic solvent residue is less than 100 ppm. [a]o 161 (0.1% H2O). Sodium deoxycholate (Reanal) 9,10-3-H-stearic acid (Izocommerc), specific radioactivity >1110 GBq/mmol (labelled stearic acid was diluted with appropriate amount of non-labelled stearic acid (Reanal) before the experiments) edible oil. 

Blood radioactivity level was considerably higher (2 to 15 fold) in DIMEB-treated groups than in those administered 3-H-stearic acid alone. The absorption enhancing effect of DIMEB was most apparent in the first two hours. On the contrary, a slow increase of blood radioactivity was observed in the case of animals treated with 3-H-stearic acid and sodium deoxycholate. In this case, a more apparent increase was observed only after the 6th hour. 

The radioactively labeled proteins of the mitochondrial membranes were separated using an amphipathic chromatographic system The stationary phase of this system is polymethacrylic acid resin, some of the carboxylic groups of which are linked to oleylamine by means of an amide bond (as outlined in Fig. 3). The mobile phase is a solution of the detergents cholate and deoxycholate. Thus, the mobile phase and the resin... 

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