Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 80 (1976), S. 8-14 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Transport of l-[3H]carnitine and acetyl-l-[3H]carnitine at the blood–brain barrier (BBB) was examined by using in vivo and in vitro models. In vivo brain uptake of acetyl-l-[3H]carnitine, determined by a rat brain perfusion technique, was decreased in the presence of unlabeled acetyl-l-carnitine and in the absence of sodium ions. Similar transport properties for l-[3H]carnitine and/or acetyl-l-[3H]carnitine were observed in primary cultured brain capillary endothelial cells (BCECs) of rat, mouse, human, porcine and bovine, and immortalized rat BCECs, RBEC1. Uptakes of l-[3H]carnitine and acetyl-l-[3H]carnitine by RBEC1 were sodium ion-dependent, saturable with Km values of 33.1 ± 11.4 µm and 31.3 ± 11.6 µm, respectively, and inhibited by carnitine analogs. These transport properties are consistent with those of carnitine transport by OCTN2. OCTN2 was confirmed to be expressed in rat and human BCECs by an RT-PCR method. Furthermore, the uptake of acetyl-l-[3H]carnitine by the BCECs of juvenile visceral steatosis (jvs) mouse, in which OCTN2 is functionally defective owing to a genetical missense mutation of one amino acid residue, was reduced. The brain distributions of l-[3H]carnitine and acetyl-l-[3H]carnitine in jvs mice were slightly lower than those of wild-type mice at 4 h after intravenous administration. These results suggest that OCTN2 is involved in transport of l-carnitine and acetyl-l-carnitine from the circulating blood to the brain across the BBB.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 67 (1996), S. 0 
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The characteristics of β-alanine transport at the blood-brain barrier were studied by using primary cultured bovine brain capillary endothelial cells. Kinetic analysis of the β-[3H]alanine transport indicated that the transporter for β-alanine functions with Kt of 25.3 ± 2.5 µM and Jmax of 6.90 ± 0.48 nmol/30 min/mg of protein in the brain capillary endothelial cells. β-[3H]Alanine uptake is mediated by an active transporter, because metabolic inhibitors (2,4-dinitrophenol and NaN3) and low temperature reduced the uptake significantly. Furthermore, the uptake of β-[3H]alanine required Na+ and Cl− in the external medium. Stoichiometric analysis of the transport demonstrated that two sodium ions and one chloride ion are associated with one β-alanine molecule. The Na+ and Cl−-dependent uptake of β-[3H]alanine was stimulated by a valinomycin-induced inside-negative K+-diffusion potential. β-Amino acids (β-alanine, taurine, and hypotaurine) inhibited strongly the uptake of β-[3H]alanine, whereas α- and γ-amino acids had little or no inhibitory effect. In ATP-depleted cells, the uptake of β-[3H]alanine was stimulated by preloading of β-alanine or taurine but not l-leucine. These results show that β-alanine is taken up by brain capillary endothelial cells, via the secondary active transport mechanism that is common to β-amino acids.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1442-2042
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: We previously reported that hemin-induced mitogenicity in mouse splenocytes was potentiated up to two-fold by interleukin (IL)-2, and the combination of hemin and IL-2 was also effective in inducing cytotoxicity for NK-resistant target cells. The purpose of this study was to investigate the effects of hemin both on expression of membrane surface receptors and on production of cytokine in human peripheral blood mononuclear cells (PBMC).Methods: Human PBMC were obtained from 16 healthy volunteers. We analyzed hemin-mediated surface phenotypes of cells using flow cytometry, and levels of tumor necrosis factor (TNF)-α and interferon (1FN)-γ in the culture-supernatant of cells by ELSA system.Results: Hemin induced increased expression of both transferring receptor and IL-2 receptor (CD25) on PBMC in a dose-dependent manner. When the combination of hemin (30μno//L) and IL-2 (100U/mL) was added to the culture of PBMC, the population of double positive cells was increased up to 70.4%. These effects of hemin were enhanced by the addition of catalase in the culture. Treatment with hemin plus IL-2 effectively enhanced the production of TNF-α and IFN-γ in PBMC.Conclusion: Hemin upregulated both IL-2 receptor and transferrin receptor expression, and stimulated TNF-α: and IFN-γ production in PBMC. IL-2 cooperated with hemin in eliciting these effects.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1546-1718
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Medicine
    Notes: [Auszug] Primary systemic carnitine deficiency (SCD; OMIM 212140) is an autosomal recessive disorder characterized by progressive cardiomyopathy, skeletal myopathy, hypoglycaemia and hyperammonaemia. SCD has also been linked to sudden infant death syndrome. Membrane-physiological studies have suggested ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] A number of proteins are known to be involved in apical/basolateral transport of proteins in polarized epithelial cells. The small GTP-binding protein Rab8 was thought to regulate basolateral transport in polarized kidney epithelial cells through the AP1B-complex-mediated pathway. However, the ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1573-904X
    Keywords: pravastatin ; lovastatin ; simvastatin ; 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor ; blood–brain barrier (BBB) transport ; brain perfusion ; cultured brain capillary endothelial cell ; central nervous system (CNS) side effect ; lipophilicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Among the HMG-CoA reductase inhibitors, lovastatin and simvastatin have central nervous system (CNS) side effects, such as sleep disturbance, whereas pravastatin does not. This difference in CNS side effects may be due to a difference in blood–brain barrier (BBB) permeability among these inhibitors. To test this hypothesis, we compared the BBB transport ability of HMG-CoA reductase inhibitors by using an in vivo brain perfusion technique in rats and an in vitro culture system of bovine brain capillary endothelial cells. The in vivo BBB permeability coefficients of the lipophilic inhibitors, [14C]lovastatin and [14C]simvastatin, were high. In contrast, that of the hydrophilic inhibitor, [14C]pravastatin, was low and not significantly different from that of [14C]sucrose, an extracellular space marker. Similarly, the in vitro BBB permeability coefficients of [14C]lovastatin and [1C]simvastatin were high, while that of [14C]-pravastatin was low. The in vivo and in vitro transcellular permeabilities obtained for HMG-CoA reductase inhibitors were comparable. This study shows that the BBB permeability correlates with the CNS side effects of the HMG-CoA reductase inhibitors.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1573-904X
    Keywords: drug delivery ; emulsion ; entrapping efficiency ; polydimethylsiloxane ; glass beads ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Evaluation of entrapping efficiency is difficult for an o/w emulsion formulation containing a lipophilic oily drug, isocarbacyclin methyl ester (TEI-9090), by commonly employed techniques (dialysis, ultrafiltration, or gel filtration), because of its adsorption to the system materials. Employing this characteristic of TEI-9090, we developed an adsorption technique with polydimethylsiloxane-coated glass beads (PDMS-GB). The assay is based on the quantitative adsorption of unentrapped TEI-9090 to the PDMS-GB. The entrapping efficiency of a 10% soybean oil emulsion containing [3H]TEI-9090 (1 µg/mL) assayed by this method approached 100%. The PDMS-GB assay was performed for the emulsion diluted 100 times with physiological saline at different time intervals after dilution over a period of 24 hr. A plot of [3H]TEI-9090 in the emulsion particles versus time showed rapid release within 1 hr, followed by very slow release, reaching equilibrium. Applying first-order kinetics, the data were found to fit to a biexponential equation over the first hour of release. The terminal release resembled the first-order release of the drug from the phospholipid-rich infranatant, which was separated from the creamy layer by ultracentrifugation of the emulsion and contained 35% [3H]TEI-9090. These results suggest that the drug is released from two components in the emulsion.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-904X
    Keywords: benzoic acid ; Caco-2 cell ; Monocarboxylic acid ; pH-dependent carrier-mediated transport ; pH-partition theory ; proton-coupled transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pH-dependent transcellular transport of [14 C]benzoic acid across a Caco-2 cell monolayer is shown to be mediated by a monocarboxylic acid-specific carrier-mediated transport system, localized on the apical membrane. Evidence for the carrier-mediated transport of benzoic acid includes (a) the significant temperature and concentration dependence, (b) the metabolic energy dependence, (c) the inhibition by unlabeled benzoic acid and other monocarboxylic acids, (d) countertransport effects on the uptake of [14C]benzoic acid, and (e) effects of a proteinase (papain) and amino acid-modifying reagents. Furthermore, since carbonylcyanide p-trifluoromethoxyphenylhydrazone and nigericin significantly inhibited the transport of [14C] benzoic acid, the direct driving force for benzoic acid transport is suggested to be the inwardly directed proton gradient. From these results, together with previous observations using intestinal brush border membrane vesicles, the pH dependence of the transcellular transport of certain organic weak acids across Caco-2 cells is considered to result mainly from a proton gradient-dependent, carrier-mediated transport mechanism, rather than passive diffusion according to the pH-partition theory.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-904X
    Keywords: o/w emulsion ; serum ; entrapping efficiency ; kinetics ; SDS
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...