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Biodistribution And Biopersistence Of Ceria Engineered Nanomaterials: Size Dependence, Robert A. Yokel, Michael T. Tseng, Mo Dan, Jason M. Unrine, Uschi M. Graham, Peng Wu, Eric A. Grulke

Pharmaceutical Sciences Faculty Publications

The aims were to determine the biodistribution, translocation, and persistence of nanoceria in the brain and selected peripheral organs. Nanoceria is being studied as an anti-oxidant therapeutic. Five, 15, 30, or 55 nm ceria was iv infused into rats which were terminated 1, 20, or 720 h later. Cerium was determined in blood, brain, liver, and spleen. Liver and spleen contained a large percentage of the dose, from which there was no significant clearance over 720 h, associated with adverse changes. Very little nanoceria entered brain parenchyma. The results suggest brain delivery of nanoceria will be a challenge.

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Loss Of Dendritic Inhibition In The Hippocampus After Repeated Early-Life Hyperthermic Seizures In Rats., Richard Boyce, L Stan Leung

Physiology and Pharmacology Publications

Seizures are relatively common in children and are a risk factor for subsequent temporal lobe epilepsy. To investigate whether early-life seizures themselves are detrimental to the proper function of the adult brain, we studied whether dendritic excitation and inhibition in the hippocampus of adult rats were altered after hyperthermia-induced seizures in immature rats. In particular, we hypothesized that apical dendritic inhibition in hippocampal CA1 pyramidal cells would be disrupted following hyperthermia-induced seizures in early life. Seizure rats were given three hyperthermia-induced seizures per day for three days from postnatal day (PND) 13 to 15; control rats were handled similarly but …

Septohippocampal Gabaergic Neurons Mediate The Altered Behaviors Induced By N-Methyl-D-Aspartate Receptor Antagonists., Jingyi Ma, Siew Kian Tai, L Stan Leung

Physiology and Pharmacology Publications

We hypothesize that selective lesion of the septohippocampal GABAergic neurons suppresses the altered behaviors induced by an N-methyl-D-aspartate (NMDA) receptor antagonist, ketamine or MK-801. In addition, we hypothesize that septohippocampal GABAergic neurons generate an atropine-resistant theta rhythm that coexists with an atropine-sensitive theta rhythm in the hippocampus. Infusion of orexin-saporin (ore-SAP) into the medial septal area decreased parvalbumin-immunoreactive (GABAergic) neurons by ~80%, without significantly affecting choline-acetyltransferase-immunoreactive (cholinergic) neurons. The theta rhythm during walking, or the immobility-associated theta induced by pilocarpine, was not different between ore-SAP and sham-lesion rats. Walking theta was, however, more disrupted by atropine sulfate in ore-SAP than …

Rat Brain Pro-Oxidant Effects Of Peripherally Administered 5 Nm Ceria 30 Days After Exposure, Sarita S. Hardas, Rukhsana Sultana, Govind Warrier, Mo Dan, Rebecca L. Florence, Peng Wu, Eric A. Grulke, Michael T. Tseng, Jason M. Unrine, Uschi M. Graham, Robert A. Yokel, D. Allan Butterfield

Chemistry Faculty Publications

The objective of this study was to determine the residual pro-or anti-oxidant effects in rat brain 30 days after systemic administration of a 5 nm citrate-stabilized ceria dispersion. A ∼4% aqueous ceria dispersion was iv-infused (0 or 85 mg/kg) into rats which were terminated 30 days later. Ceria concentration, localization, and chemical speciation in the brain was assessed by inductively coupled plasma mass spectrometry (ICP-MS), light and electron microscopy (EM), and electron energy loss spectroscopy (EELS), respectively. Pro- or anti-oxidant effects were evaluated by measuring levels of protein carbonyls (PC), 3-nitrotyrosine (3NT), and protein-bound-4-hydroxy-2-trans-nonenal (HNE) in the hippocampus, cortex, and …

Brain Microvascular Endothelial Cell Association And Distribution Of A 5 Nm Ceria Engineered Nanomaterial, Mo Dan, Michael T. Tseng, Peng Wu, Jason M. Unrine, Eric A. Grulke, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

PURPOSE: Ceria engineered nanomaterials (ENMs) have current commercial applications and both neuroprotective and toxic effects. Our hypothesis is that ceria ENMs can associate with brain capillary cells and/or cross the blood-brain barrier.

METHODS: An aqueous dispersion of ∼5 nm ceria ENM was synthesized and characterized in house. Its uptake space in the Sprague Dawley rat brain was determined using the in situ brain perfusion technique at 15 and 20 mL/minute flow rates; 30, 100, and 500 μg/mL ceria perfused for 120 seconds at 20 mL/minute; and 30 μg/mL perfused for 20, 60, and 120 seconds at 20 mL/minute. The capillary …

Localization And Functional Characterization Of The Rat Oatp4c1 Transporter In An In Vitro Cell System And Rat Tissues, Kuei-Ling Kuo, Haining Zhu, Patrick J. Mcnamara, Markos Leggas

Pharmaceutical Sciences Faculty Publications

The organic anion transporting polypeptide 4c1 (Oatp4c1) was previously identified as a novel uptake transporter predominantly expressed at the basolateral membrane in the rat kidney proximal tubules. Its functional role was suggested to be a vectorial transport partner of an apically-expressed efflux transporter for the efficient translocation of physiological substrates into urine, some of which were suggested to be uremic toxins. However, our in vitro studies with MDCKII cells showed that upon transfection rat Oatp4c1 polarizes to the apical membrane. In this report, we validated the trafficking and function of Oatp4c1 in polarized cell systems as well as its subcellular …

Distribution, Elimination, And Biopersistence To 90 Days Of A Systemically Introduced 30 Nm Ceria-Engineered Nanomaterial In Rats, Robert A. Yokel, Tu C. Au, Robert Macphail, Sarita S. Hardas, D. Allan Butterfield, Rukhsana Sultana, Michael Goodman, Michael T. Tseng, Mo Dan, Hamed Haghnazar, Jason M. Unrine, Uschi M. Graham, Peng Wu, Eric A. Grulke

Pharmaceutical Sciences Faculty Publications

Nanoceria is used as a catalyst in diesel fuel, as an abrasive in printed circuit manufacture, and is being pursued as an antioxidant therapeutic. Our objective is to extend previous findings showing that there were no reductions of cerium in organs of the mononuclear phagocyte (reticuloendothelial) system up to 30 days after a single nanoscale ceria administration. An ~5% aqueous dispersion of citrate-stabilized 30 nm ceria, synthesized and characterized in-house, or vehicle, was iv infused into rats terminated 1, 7, 30, or 90 days later. Cageside observations were obtained daily, body weight weekly. Daily urinary and fecal cerium outputs were …

Ceria-Engineered Nanomaterial Distribution In, And Clearance From, Blood: Size Matters, Mo Dan, Peng Wu, Eric A. Grulke, Uschi M. Graham, Jason M. Unrine, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

AIMS: Characterize different sized ceria-engineered nanomaterial (ENM) distribution in, and clearance from, blood (compared to the cerium ion) following intravenous infusion.

MATERIALS & METHODS: Cerium (Ce) was quantified in whole blood, serum and clot (the formed elements) up to 720 h.

RESULTS: Traditional pharmacokinetic modeling showed best fit for 5 nm ceria ENM and the cerium ion. Ceria ENMs larger than 5 nm were rapidly cleared from blood. After initially declining, whole blood 15 and 30 nm ceria increased (results that have not been well-described by traditional pharmacokinetic modeling). The cerium ion and 5 and 55 nm ceria did not …

A Model Of Intracellular Θ Phase Precession Dependent On Intrinsic Subthreshold Membrane Currents., L Stan Leung

Physiology and Pharmacology Publications

A hippocampal place cell fires at an increasingly earlier phase in relation to the extracellular theta rhythm as a rodent moves through the place field. The present report presents a compartment model of a CA1 pyramidal cell that explains the increase in amplitude and the phase precession of intracellular theta oscillations, with the assumption that the cell receives an asymmetric ramp depolarization (<10 >mV) in the place field and rhythmic inhibitory and/or excitatory synaptic driving. Intracellular subthreshold membrane potential oscillations (MPOs) increase in amplitude and frequency, and show phase precession within the place field. Theta phase precession and MPO power …

The Marine Sponge Metabolite Mycothiazole: A Novel Prototype Mitochondrial Complex I Inhibitor., J Brian Morgan, Fakhri Mahdi, Yang Liu, Veena Coothankandaswamy, Mika B. Jekabsons, Tyler A. Johnson, Koneni V. Sashidhara, Phillip Crews, Dale G. Nagle, Yu-Dong Zhou

Natural Sciences and Mathematics | Faculty Scholarship

A natural product chemistry-based approach was applied to discover small-molecule inhibitors of hypoxia-inducible factor-1 (HIF-1). A Petrosaspongia mycofijiensis marine sponge extract yielded mycothiazole (1), a solid tumor selective compound with no known mechanism for its cell line-dependent cytotoxic activity. Compound 1 inhibited hypoxic HIF-1 signaling in tumor cells (IC(50) 1nM) that correlated with the suppression of hypoxia-stimulated tumor angiogenesis in vitro. However, 1 exhibited pronounced neurotoxicity in vitro. Mechanistic studies revealed that 1 selectively suppresses mitochondrial respiration at complex I (NADH-ubiquinone oxidoreductase). Unlike rotenone, MPP(+), annonaceous acetogenins, piericidin A, and other complex I inhibitors, mycothiazole is a mixed polyketide/peptide-derived compound …

Manganese Flux Across The Blood-Brain Barrier, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is essential for brain growth and metabolism, but in excess can be a neurotoxicant. The chemical form (species) of Mn influences its kinetics and toxicity. Significant Mn species entering the brain are the Mn²⁺ ion and Mn citrate which, along with Mn transferrin, enter the brain by carrier-mediated processes. Although the divalent metal transporter (DMT-1) was suggested to be a candidate for brain Mn uptake, brain Mn influx was not different in Belgrade rats, which do not express functional DMT-1, compared to controls. Brain Mn influx was not sodium dependent or dependent on ATP hydrolysis, but was …

Aluminum Bioavailability From Tea Infusion, Robert A. Yokel, Rebecca L. Florence

Pharmaceutical Sciences Faculty Publications

The objective was to estimate oral Al bioavailability from tea infusion in the rat, using the tracer ²⁶Al. ²⁶Al citrate was injected into tea leaves. An infusion was prepared from the dried leaves and given intra-gastrically to rats which received concurrent intravenous ²⁷Al infusion. Oral Al bioavailability (F) was calculated from the area under the ²⁶Al, compared to ²⁷Al, serum concentration × time curves. Bioavailability from tea averaged 0.37%; not significantly different from water (F = 0.3%), or basic sodium aluminum phosphate (SALP) in cheese (F = 0.1 to 0.3%), but greater than acidic SALP …

Manufactured Aluminum Oxide Nanoparticles Decrease Expression Of Tight Junction Proteins In Brain Vasculature, Lei Chen, Robert A. Yokel, Bernhard Hennig, Michal Toborek

Pharmaceutical Sciences Faculty Publications

Manufactured nanoparticles of aluminum oxide (nano-alumina) have been widely used in the environment; however, their potential toxicity provides a growing concern for human health. The present study focuses on the hypothesis that nano-alumina can affect the blood-brain barrier and induce endothelial toxicity. In the first series of experiments, human brain microvascular endothelial cells (HBMEC) were exposed to alumina and control nanoparticles in dose- and time-responsive manners. Treatment with nano-alumina markedly reduced HBMEC viability, altered mitochondrial potential, increased cellular oxidation, and decreased tight junction protein expression as compared to control nanoparticles. Alterations of tight junction protein levels were prevented by cellular …

Aluminum Bioavailability From Basic Sodium Aluminum Phosphate, An Approved Food Additive Emulsifying Agent, Incorporated In Cheese, Robert A. Yokel, Clair L. Hicks, Rebecca L. Florence

Pharmaceutical Sciences Faculty Publications

Oral aluminum (Al) bioavailability from drinking water has been previously estimated, but there is little information on Al bioavailability from foods. It was suggested that oral Al bioavailability from drinking water is much greater than from foods. The objective was to further test this hypothesis. Oral Al bioavailability was determined in the rat from basic [26Al]-sodium aluminum phosphate (basic SALP) in a process cheese. Consumption of approximately 1g cheese containing 1.5% or 3% basic SALP resulted in oral Al bioavailability (F) of approximately 0.1% and 0.3%, respectively, and time to maximum serum 26Al concentration (Tmax) of 8-9h. These Al bioavailability …

Aluminum Bioavailability From The Approved Food Additive Leavening Agent Acidic Sodium Aluminum Phosphate, Incorporated Into A Baked Good, Is Lower Than From Water, Robert A. Yokel, Rebecca L. Florence

Pharmaceutical Sciences Faculty Publications

There are estimates of oral aluminum (Al) bioavailability from drinking water, but little information on Al bioavailability from foods. Foods contribute ∼95% and drinking water 1–2% of the typical human's daily Al intake. The objectives were to estimate oral Al bioavailability from a representative food containing the food additive acidic sodium aluminum phosphate (acidic SALP), a leavening agent in baked goods. Rats were acclimated to a special diet that resulted in no stomach contents 14 h after its withdrawal. They were trained to rapidly consume a biscuit containing 1.5% acidic SALP. Oral Al bioavailability was then determined from a biscuit …

Manganese Distribution Across The Blood-Brain Barrier. Iv. Evidence For Brain Influx Through Store-Operated Calcium Channels, Janelle S. Crossgrove, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is a required co-factor for many ubiquitous enzymes; however, chronic Mn overexposure can cause manganism, a parkinsonian-like syndrome. Previous studies showed Mn influx into brain is carrier-mediated, though the putative carrier(s) were not established. Studies conducted with cultured bovine brain microvascular endothelial cells (bBMECs), which comprise the blood–brain barrier, revealed ⁵⁴Mn (II) uptake positively correlated with pH, was temperature-dependent, and was sodium- and energy-independent. Brain ⁵⁴Mn uptake correlated inversely with calcium (Ca) concentration, but ⁴⁵Ca uptake was unaltered by high Mn concentration. Lanthanum (La), a non-selective inhibitor of several Ca channel types, as well as …

Hepatic Disposition Of Cyclosporine A In Isolated Perfused Rat Livers, Reza Mehvar, Anjaneya Chimalakonda

Pharmacy Faculty Articles and Research

PURPOSE. To develop an isolated perfused rat liver model to study the hepatic disposition of cyclosporine A (CyA) in both sexes.

METHODS. Livers were isolated from male (n = 6) and female (n = 7) rats and perfused with a physiological buffer in a single-pass manner. A bolus 1-mg dose of CyA was injected into the inlet catheter and periodical samples (0-15 min) were collected from the outlet perfusate. The concentrations of CyA in the outlet perfusate, collected bile (0-15 min), and liver tissue (at the end of perfusion) were quantitated by HPLC and subjected to statistical moment analysis. …

Manganese Distribution Across The Blood-Brain Barrier. I. Evidence For Carrier-Mediated Influx Of Managanese Citrate As Well As Manganese And Manganese Transferrin, Janelle S. Crossgrove, David D. Allen, Bonny L. Bukaveckas, Susan S. Rhineheimer, Robert A. Yokel

Pharmaceutical Sciences Faculty Publications

Manganese (Mn) is an essential element and a neurotoxicant. Regulation of Mn movement across the blood–brain barrier (BBB) contributes to whether the brain Mn concentration is functional or toxic. In plasma, Mn associates with water, small molecular weight ligands and proteins. Mn speciation may influence the kinetics of its movement through the BBB. In the present work, the brain influx rates of ⁵⁴Mn²⁺, ⁵⁴Mn citrate and ⁵⁴Mn transferrin (⁵⁴Mn Tf) were determined using the in situ brain perfusion technique. The influx rates were compared to their predicted diffusion rates, which were determined from …

Return To Fertility After Extended Chemical Castration With A Gnrh Antagonist, Janusz W. Kostanski, Ge Jiang, Bhas A. Dani, Santos B. Murty, Wei Qiu, Bruce Schrier, B. C. Thanoo, Patrick P. Deluca

Pharmaceutical Sciences Faculty Publications

BACKGROUND: Antagonistic analogues of GnRH for the treatment of prostate cancer may be used clinically in persons for whom return to fertility after such treatment is important or desirable. The purpose of this study was, therefore, to evaluate the effects of a long term treatment with orntide, a GnRH antagonist, on testosterone levels and fertility in male rats.

METHODS: Two groups of male rats received either 120-day orntide microspheres (8.8 mg orntide/kg/120 days) or vehicle alone (control group). Serum orntide and testosterone levels in both groups were monitored at certain intervals for 9 months from the initiation of treatment. After …

Contractility Of Isolated Cardiac Muscle Obtained From Normotensive And Treated Or Untreated Hypertensive Rat Hearts : Effects Of Inotropic Agents, Mary Bassey Amanam

University of the Pacific Theses and Dissertations

In the present study, the contractility of isolated cardiac muscle obtained from normotensive and treated or untreated hypertensive rat hearts were investigated. The effects of inotropic agents were also explored •

Some SHRs were subjected to chronic antihypertensive treatment. After their blood pressure had been lowered, positive and negative inotropic agents were used to study the papillary muscles. The effects of acidosis, increased extracellular calcium, hypoxia, and reoxygenation on the isolated papillary muscles obtained from their hearts were studied. The same was done for isolated cardiac muscles that were removed from WKYs and SHRs. Isoproterenol in the absence or presence …