@article {4611,
	title = {A H-1-NMR study of the permeation of glycolic acid through phospholipid membranes},
	journal = {Biochimica Et Biophysica Acta-Biomembranes},
	volume = {1416},
	number = {1-2},
	year = {1999},
	note = {ISI Document Delivery No.: 162BFTimes Cited: 10Cited Reference Count: 31},
	month = {Jan},
	pages = {333-338},
	type = {Article},
	abstract = {The transmembrane permeability coefficient of the alpha-hydroxyacid, glycolic acid, has been measured for egg phosphatidylcholine large unilamellar vesicles. The determination of the vesicle concentration independent first-order rate constant for membrane transport and the permeability coefficient were made using an NMR technique employing shift agents. Both the temperature dependence and the dependence on cholesterol content were investigated. The activation energy and the Arrhenius pre-exponential factor were found to be dependent on the cholesterol content. A marked increase in both parameters was observed up to 20 mol\% cholesterol, with a further, small increase up to 50\%. The pH dependence of permeability was also investigated. An increase in permeability is observed with a decrease in pH, providing a possible explanation for the effectiveness of glycolic acid in skin treatment. (C) 1999 Published by Elsevier Science B.V. All rights reserved.},
	keywords = {ACETIC-ACID, acne, aging of the, BILAYER-MEMBRANES, CHOLESTEROL, CHOLESTEROL CONTENT, glycolic acid, H-1-NMR, HUMAN ERYTHROCYTES, LAIDLAWII-B-CELLS, LARGE UNILAMELLAR VESICLES, lipid, NONELECTROLYTE, NUCLEAR MAGNETIC-RESONANCE, permeability, SKIN, transmembrane permeability, TRANSPORT, WATER},
	isbn = {0005-2736},
	url = {<Go to ISI>://000078324700030},
	author = {Males, R. G. and Herring, F. G.}
}
@article {4346,
	title = {Equations describing passive transport through vesicular membranes},
	journal = {Biophysical Chemistry},
	volume = {70},
	number = {1},
	year = {1998},
	note = {ISI Document Delivery No.: YU539Times Cited: 4Cited Reference Count: 26},
	month = {Jan},
	pages = {65-74},
	type = {Article},
	abstract = {A theoretical description of the kinetics of the passive transport of both lipophobic and lipophilic nonelectrolytes, weak acids, and weak bases through membranes of large unilamellar vesicles is discussed. Equations are derived which may be used to obtain permeability coefficients and predict the extent of LW entrapment of permeant molecules. Theoretical curves are generated to illustrate the difference between lipophobic and lipophilic permeation. By applying a diffusional approach rather than a simple first order kinetic approach to the problem of passive transport, some of the inconsistencies observed in other works are corrected. (C) 1998 Elsevier Science B.V.},
	keywords = {accumulation, DIFFUSION, FATTY-ACIDS, IONS, KINETICS, LARGE UNILAMELLAR VESICLES, lipid bilayer, LIPID BILAYER-MEMBRANES, LIPOSOMES, PARTITION-COEFFICIENTS, passive, permeability, PROCEDURE, RAPID EXTRUSION, TRANSMEMBRANE PH GRADIENTS, TRANSPORT},
	isbn = {0301-4622},
	url = {<Go to ISI>://000071728000007},
	author = {Males, R. G. and Phillips, P. S. and Herring, F. G.}
}
@article {4345,
	title = {Vesicular membrane permeability of monomethylarsonic and dimethylarsinic acids},
	journal = {Biophysical Chemistry},
	volume = {70},
	number = {1},
	year = {1998},
	note = {ISI Document Delivery No.: YU539Times Cited: 6Cited Reference Count: 45},
	month = {Jan},
	pages = {75-85},
	type = {Article},
	abstract = {The transmembrane permeability coefficients of the environmentally sensitive arsenicals, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) have been measured for egg phosphatidylcholine large unilamellar vesicles. The determination of the vesicle concentration-independent first-order rate constants for membrane transport and the permeability coefficients were made using an NMR technique employing shift agents. The permeability coefficient of DMA was found to be two orders of magnitude greater than that of MMA. This is attributed to the presence of MMAs extra hydroxyl group. Both species are shown to permeate membranes in the neutral form. Both the temperature dependence and the dependence on cholesterol content were investigated for DMA. The activation energy and the Arrhenius preexponential factor were found to be dependent on the cholesterol content. A marked increase in both parameters was observed up to 20 mol.\% cholesterol, with a further, small increase up to 60\%, The significance of these results to our understanding of membrane transport is discussed. The importance of using permeability coefficients rather than n-octanol/water partition coefficients in determining bioavailability and bioaccumulation of environmentally sensitive compounds is also discussed. (C) 1998 Elsevier Science B.V.},
	keywords = {BILE-ACIDS, CHOLESTEROL, DIFFUSION, DIMETHYLARSINIC ACID, HUMAN-ERYTHROCYTES, LIPID BILAYER-MEMBRANES, monomethylarsonic acid, NONELECTROLYTE, nuclear magnetic resonance, PARTITION-COEFFICIENTS, permeability, phosphatidylcholine membranes, RAPID EXTRUSION PROCEDURE, TRANSPORT, UNILAMELLAR VESICLES},
	isbn = {0301-4622},
	url = {<Go to ISI>://000071728000008},
	author = {Males, R. G. and Nelson, J. C. and Phillips, P. S. and Cullen, W. R. and Herring, F. G.}
}
@article {3223,
	title = {EVIDENCE FOR ENERGY-DEPENDENT TRANSPORT OF ALUMINUM OUT OF BRAIN EXTRACELLULAR FLUID},
	journal = {Toxicology},
	volume = {98},
	number = {1-3},
	year = {1995},
	note = {ISI Document Delivery No.: QX943Times Cited: 22Cited Reference Count: 36},
	month = {Apr},
	pages = {31-39},
	type = {Article},
	abstract = {Aluminum (Al) can cause CNS toxicity. The mechanism of its blood-brain barrier (BBB) permeation is poorly understood. In this study, microdialysis was used to determine extracellular fluid (ECF) unbound aluminum distribution between frontal cortex (FC) and blood during steady-state aluminum concentrations. The brain/blood aluminum ratio was determined. Over a 16-fold range of aluminum concentrations (dosed as aluminum citrate), brain/blood aluminum ratios were 0.10-0.15, consistently and significantly <1. Aluminum diffusion cannot account for these results, suggesting the presence of a carrier that moves aluminum out of brain extracellular fluid. These aluminum brain/blood ratios (BBRs) were not significantly different over the range of concentrations studied, suggesting an inability to saturate the carrier. Brain/blood aluminum ratios obtained with four aluminum-hydroxypyridinones were also significantly <1 (0.1-0.3), and were generally significantly different among themselves and from the aluminum citrate BBR. Movement of a BBB permeability marker from blood into brain extracellular fluid suggested partial BBB opening. The aluminum BBRs obtained (all much less than 1), in the presence of a partially opened BBR, suggest an efficient carrier moving aluminum out of brain ECF. Addition of cyanide to the brain microdialysis probe solution significantly increased the Al (citrate) BBR to 1, These results suggest the presence of an efficient, energy-dependent carrier that removes aluminum from brain ECF, either into brain cells or blood.},
	keywords = {aluminum, ANTIPYRINE, BARRIER, BLOOD, BLOOD-BRAIN BARRIER, CHELATORS INVITRO, COMPLEXES, ENERGY-DEPENDENT ACTIVE TRANSPORT, INVIVO MICRODIALYSIS, iron, MICRODIALYSIS, MOBILIZATION, permeability, TRANSFERRIN},
	isbn = {0300-483X},
	url = {<Go to ISI>://A1995QX94300004},
	author = {Allen, D. D. and Orvig, Chris and Yokel, R. A.}
}
@article {2953,
	title = {PHARMACOKINETICS AND DISTRIBUTION OF TRIS(MALTOLATO)ALUMINUM(III) INTO THE CENTRAL-NERVOUS-SYSTEM},
	journal = {Neurotoxicology},
	volume = {15},
	number = {2},
	year = {1994},
	note = {ISI Document Delivery No.: PB305Times Cited: 4Cited Reference Count: 37},
	month = {Sum},
	pages = {371-378},
	type = {Article},
	abstract = {The maltolate compound of aluminum (Al), tris(maltolato)aluminum(III), has been demonstrated to be quite toxic after central administration and in cell cultures. However, reports of peripheral Al-maltolate administration in vivo demonstrated un impressive neurological effects. We found no reports of Al-maltolate pharmacokinetics or its distribution into the central nervous system (CNS) after systemic administration. In the present study, we evaluated Al pharmacokinetics in serum and Al distribution into brain extracellular fluid (ECF) in rats following Al-maltolate administration. The pharmacokinetic studies revealed that systemic clearance, elimination half-life and mean residence time were 42 (+/- 5) ml/hr/kg, 2.2 (+/- 0.5) hr and 3.1 (+/- 0.7) hr [mean+/-SD), respectively. The steady state volume of distribution (V-ss) for Al-maltolate was 130 ml/kg. This V-ss suggests that Al-maltolate may exhibit limited distribution outside the vascular compartment, which is estimated to be approximate to 80 ml/kg in these rats. Previously, we used microdialysis (MD) probes to assess Al-citrate distribution into the CNS. MD was utilized in the present study to evaluate the CNS distribution of Al as a result of Al-maltolate administration. MD probes were implanted into the frontal cortex (FC) and jugular vein to sample Al from brain and blood ECF, respectively. Al was not measurable in FC MD probe dialysates after a 0.5 mmol/kg Al (as maltolate) bolus, but could be measured after steady state blood and brain ECF Al concentrations had been achieved. The Al brain/blood ra tio calculated from Al-maltolate steady state brain and blood MD samples was 0.04, significantly less than those calculated for other Al salts at equimolar Al doses. The present study suggests that unless it is administered centrally, Al-maltolate might render minimal neurological insult because of its minimal permeation into brain extracellular space. (C) 1994 Intox Press, Inc.},
	keywords = {ALUMINUM MALTOL, ALUMINUM NEUROTOXICITY, ALUMINUM PHARMACOKINETICS, ALUMINUM-MALTOLATE, BLOOD-BRAIN-BARRIER, COMPLEXES, DIALYSIS, ENCEPHALOPATHY, EQUILIBRIUM, gallium, INVIVO MICRODIALYSIS, MICRODIALYSIS, permeability, RABBITS, SERUM},
	isbn = {0161-813X},
	url = {<Go to ISI>://A1994PB30500014},
	author = {Allen, D. D. and Orvig, Chris and Yokel, R. A.}
}
