• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.111-114
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• 2008

Adsorption isotherm with the most fundamental information related to chromatography process is obtained experimentally. The adsorption isotherm of 2-deoxyuridine (dUrd) and 2-deoxycytidine (dCyd) with ${\mu}$-Bondapak $C_{18}$, static method was adopted in RP-HPLC. The concentrations of mobile and stationary phases were measured with different initial concentrations of dUrd and dCyd, 1, 3, 5, 7, 10 mg/mL, respectively. The adsorption isotherm data were applied by Freundlich, Langmuir, Sips, and Radke-Prausnitz model equations. As a result of the regression analysis, standard error between adsorption isotherm of dUrd and Radke-Prausnitz equation was very low, and adsorption isotherm of dCyd was in an agreement with Sips equation very well.

• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.91-100
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• 1990

The benzylacycoluridines (BAU and BBAU) are potent and specific inhibitors of uridine phosphorylase (UrdPase). In contrast to the report that benzylacyclouridines potentiated 5-fluoro-2'-deoxyuridine (FdUrd) cytotoxicity against human solid tumor cells (Cancer Res., 44:1852, 1984), continuous exposure of mouse lymphoma L5178Y cells, to FdURd, 5-fluorouridine (FUrd), 5'-deoxy-5-fluorouridine (5'-dFUrd), or 5-fluorouracil (FUra) showed no potentiation of cytotoxicity by benzylacyclouridines. In fact, under the conditions employed, benzylacycoluridines protected the cells from the cytotoxicity of FdUrd, FUrd, or 5'-dFUrd, but not FUra in a dose dependent manner. Intraperitoneal coadministration of BAU or BBAU and a 5-fluorinated pyrimidine (i.e., FdUrd, FUrd, or FUra), to mice bearing L5178Y cells also did not significantly increase the life span compared to those treated with the antimetabolites alone. Anabolism of these nucleosides through the sequential action of UrdPase and orotate phosphoribosyltransferase (OPRTase), inhibition of nucleoside transport by benzylacyclouridines, or both could be responsible for the ineffectiveness of UrdPase inhibitors to potentiate the antineoplastic activity of fluoropvrimidines in L5178Y cells.

• Korean Chemical Engineering Research
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• v.43 no.2
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• pp.230-235
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• 2005

Reversed-phase high-performance liquid chromatography (RP-HPLC) was used to determine the equilibrium isotherm of single and multi-components of dUrd(2'-deoxyuridine), dGuo(2'-deoxyguanosine), and dAdo(2'-deoxyadenosine) of 2'-deoxyribonucleosides by dynamic method. The composition of mobile phase was 90/10 vol.% (water/MeOH). With an increase in the injection volumes, the retention times were shorter and the peak shapes were triangle-shaped, so Langmuir-type isotherm was assumed. The Langmuir adsorption parameters were estimated by PIM (pulsed-input method), and the competitive Langmuir adsorption isotherm was further utilized. For the sample of the dUrd and dGuo whose retention times were relatively short, the agreement of between the calculated value and experimental data was fairly good in both single and multi-components, but for the dAdo, the last eluting component, some deviations were caused by non-linear and non-ideal properties.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.12
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• pp.1773-1778
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• 2008

Two experiments were carried out to study the effects of corticosterone (CORT) administration on intestinal morphology and function of broilers. In both experiments, birds were randomly divided into two equal groups. One group was the control group (CTRL), and the birds were fed with a basal diet. The other was the experimental group (CORT), and the birds were fed with the basal diet plus 30 mg of CORT/kg diet. At 21 days of age, performance, morphological characteristics of intestine, D-xylose level in plasma, activities of digestive enzymes in digesta, digestibility of nutrients and 5-bromo-2-deoxyuridine (BrdUrd)-labeling index of intestinal epithelial cells were determined. CORT administration decreased feed intake, daily gain and feed conversion ratio (p<0.05). CORT also decreased duodenal and jejunal villus height (p<0.05) as well as crypt depth (p<0.05). The D-xylose level in plasma of CORT-treated broilers was lower than that of the control (p<0.05). CORT treatment caused a decrease in apparent digestibility of protein (p<0.05), whereas fat and starch apparent digestibilities were unaffected (p>0.05). CORT administration increased activities of trypsin and amylase (p<0.05), and decreased BrdUrd-labeling index of duodenal and jejunal epithelial cells (p<0.05). In conclusion, CORT administration impaired the normal morphology and absorptive capacity of the small intestine of broiler chickens.

• The Korean Journal of Pharmacology
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• v.24 no.1
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• pp.11-16
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• 1988

Various Benzylacyclouridine (BAU, HM-BAU, suc-BAU, BBAU, HMBBAU, suc-BBAU, and BBBAU) developed as specifc inhibitors of uridine phosphorylase (UrdPase), inhibit transport (zero-trans influx) of ridine (Urd) in human erythrocytes. The inhibition pattern of these compounds is competitive, though suc-BBAU and BBBAU show a slight noncompetivieness. The order of potency as an inhibitor of the nucleoside transport system is BBAU ${\sim}$ HM-BBAU ${\sim}$ suc-BBAU > BBBAU > BAU ${\sim}$ suc-BAU ${\sim}$ HM-BAU ($K_1$ values of 19, 23, 38, 112, 124, 174 and 176 ${\mu}M$, respectively). These data indicate that there is a differnece in potency of Urd transport inhibition between the analogs of BAU and BBAU. Further, the potency correlates with the hydrophobicity of the compound, but it has a limit in the size of $C_5$ substitution. Abbreviation: BAU (5-benzylacyclouridine), 5-benzyl-1-(2'-hydroxyethoxymethyl) uracil; HM-BAU (3'-hydroxymethyl-BAU), 5-benzyl-1- [(1',3'-dihydroxy-2-propoxy) methyl]uracil; suc-BAU, 3'-succinyl-BAU; BBAU (benzyloxybenzylacyclouridine), 5-( m-benzyloxybenByl)-1-(2'-hydroxyethoxymethyl)uracil; HM-BBAU (3'-hydroxymethyl-BBAU), 5-(m-benzyloxybenzyl)-1- [(1'3'-dihyd.oxy-2-p.epoxy)methyll u.acil; suc-BAU, 3'-succinyl-BBAU; BBBAU, 5- f 3-(4-benzyloxyben-Eyl)benzyll -1-(2'-hydroxyethoxymethyl)uracil; Urdpase, uridine phosphorylase; Urd, Uridine; Fd-Urd, 5-fluoro-2'-deoxyuridine; AcThd, aoyclothyrnidine; AcUrd, acyclouridine; dThd, thymidine; NBMPR, nitrobenzylthioisone; FUra, 5-fluorouracil.