Animal Experimentation and Research Commons^™

Effects Of Chronic Cirrhosis Induced By Intraperitoneal Thioacetamide Injection On The Protein Content And Michaelis–Menten Kinetics Of Cytochrome P450 Enzymes In The Rat Liver Microsomes, Devaraj Venkatapura Chandrashekar, Barent N. Dubois, Mamunur Rashid, Reza Mehvar

Pharmacy Faculty Articles and Research

Chronic intraperitoneal injection of thioacetamide (TAA) in rats has been used as an animal model of human cirrhosis to study the effects of the disease on drug metabolism. However, TAA inhibits P450 enzymes directly and independently of cirrhosis. We investigated the effects of chronic cirrhosis in rats, induced by 10 weeks of intraperitoneal TAA, on the P450 enzymes after a 10-day washout period to eliminate TAA. Liver histology and serum biomarkers of hepatic function confirmed cirrhosis in all animals. Microsomal total P450 content, P450 reductase activity and ethoxycoumarin O-deethylase activity, a general marker of P450 activity, were significantly reduced by …

Differential Expression And Activities Of Cytochrome P450 3a In The Rat Brain Microsomes And Mitochondria, Nouf Alshammari, Devaraj Venkatapura Chandrashekar, Mamunur Rashid, Reza Mehvar

Pharmacy Faculty Articles and Research

Midazolam (MDZ), a benzodiazepine derivative, is metabolized to 1′- and 4-hydroxylated metabolites (1′-OH-MDZ and 4-OH-MDZ, respectively) by cytochrome P450 3A (CYP3A). The purpose of this study was to investigate the CYP3A-mediated hydroxylation of MDZ in the rat brain mitochondria (MT). Brain microsomes (MC) and MT fractions were prepared from rats (n = 8) using differential and density gradient centrifugations, and the purity of the fractions was evaluated using VDAC1 and calreticulin as markers of MT and MC, respectively. The formation rates of 1′-OH-MDZ and 4-OH-MDZ in the rat brain MC and MT samples were determined using an LC–MS/MS method …

Full- Versus Sub-Regional Quantification Of Amyloid-Beta Load On Mouse Brain Sections, Yuu Ohno, Riley Murphy, Matthew Choi, Weijun Ou, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Extracellular accumulation of amyloid-beta (Aβ) plaques is one of the major pathological hallmarks of Alzheimer's disease (AD), and is the target of the only FDA-approved disease-modifying treatment for AD. Accordingly, the use of transgenic mouse models that overexpress the amyloid precursor protein and thereby accumulate cerebral Aβ plaques are widely used to model human AD in mice. Therefore, immunoassays, including enzyme-linked immunosorbent assay (ELISA) and immunostaining, commonly measure the Aβ load in brain tissues derived from AD transgenic mice. Though the methods for Aβ detection and quantification have been well established and documented, the impact of the size of the …

Biologic Tnf-Α Inhibitors Reduce Microgliosis, Neuronal Loss, And Tau Phosphorylation In A Transgenic Mouse Model Of Tauopathy, Weijun Ou, Joshua Yang, Juste Simanauskaite, Matthew Choi, Demi M. Castellanos, Rudy Chang, Jiahong Sun, Nataraj Jagadeesan, Karen D. Parfitt, David H. Cribbs, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Background

Tumor necrosis factor-α (TNF-α) plays a central role in Alzheimer’s disease (AD) pathology, making biologic TNF-α inhibitors (TNFIs), including etanercept, viable therapeutics for AD. The protective effects of biologic TNFIs on AD hallmark pathology (Aβ deposition and tau pathology) have been demonstrated. However, the effects of biologic TNFIs on Aβ-independent tau pathology have not been reported. Existing biologic TNFIs do not cross the blood–brain barrier (BBB), therefore we engineered a BBB-penetrating biologic TNFI by fusing the extracellular domain of the type-II human TNF-α receptor (TNFR) to a transferrin receptor antibody (TfRMAb) that ferries the TNFR into the brain via …

The Concentration Of Brain Homogenates With The Amicon Ultra Centrifugal Filters, Joshua Yang, Rachita K. Sumbria

Pharmacy Faculty Articles and Research

Accurately measuring the brain concentration of a neurotherapeutic is critical in determining its pharmacokinetic profile in vivo. Biologics are potential therapeutics for neurologic diseases and biologics fused to an antibody targeting a transcytosis receptor at the Blood-Brain Barrier, designated as antibody-biologic fusion proteins, are Blood-Brain Barrier penetrating neurotherapeutics. The use of sandwich immunosorbent assays to measure concentrations of antibody-biologic fusion proteins in brain homogenates has become increasingly popular. The raw brain homogenate contains many proteins and other macromolecules that can cause a matrix effect, potentially interfering with the limit of detection of such assays and reduce the overall sample …

Exogenous Surfactant As A Delivery Vehicle For Intrapulmonary Therapeutics, Brandon J. Baer

Electronic Thesis and Dissertation Repository

As an organ system, the lung has unique advantages and disadvantages for direct drug delivery. Its contact with the external environment allows for the airways to be easily accessible to intrapulmonary delivery. However, its complex structure, which divides into more narrow airways with each branch, can make direct delivery to the remote alveoli challenging. The objective of this thesis was to overcome this issue by using exogenous surfactant, a lipoprotein complex used to treat neonatal respiratory distress syndrome, as a carrier for pulmonary therapeutics. It was hypothesized that therapeutics administered with a surfactant vehicle would display enhanced delivery to the …

Uplc-Ms/Ms Analysis Of The Michaelis-Menten Kinetics Of Cyp3a-Mediated Midazolam 1′- And 4-Hydroxylation In Rat Brain Microsomes, Devaraj Venkatapura Chandrashekar, Barent Dubois, Reza Mehvar

Pharmacy Faculty Articles and Research

Midazolam (MDZ) is a short-acting benzodiazepine with rapid onset of action, which is metabolized by CYP3A isoenzymes to two hydroxylated metabolites, 1′-hydroxymidazolam and 4-hydroxymidazolam. The drug is also commonly used as a marker of CYP3A activity in the liver microsomes. However, the kinetics of CYP3A-mediated hydroxylation of MDZ in the brain, which contains much lower CYP content than the liver, have not been reported. In this study, UPLC-MS/MS and metabolic incubation methods were developed and validated for simultaneous measurement of low concentrations of both hydroxylated metabolites of MDZ in brain microsomes. Different concentrations of MDZ (1–500 µM) were incubated with …

Measuring The Effects Of Lobinaline-N-Bioxide (419) On Alcohol Consumption, Nicotine Locomotor Sensitization, And Conditioned Place Preference In Mice And Rats, Cocanut M. Suhail

Theses and Dissertations--Medical Sciences

Objective: Novel drug 419 was examined to see the effect it has in vivo mice and rats on alcohol consumption, nicotine locomotor sensitization, and conditioned place preference (CPP) models regarding behavioral tests on dopamine transporter activity.

Methods: Mice and rats were used to see how they react to the drug 419 and control vehicle, in each of the models. The animals were assessed to pre- and post- drug administration of novel drug 419. We examined each model to see the association between how drug 419 will help with treating drug abuse.

Results: We found that in alcohol consumption model the …

Development And Preclinical Evaluation Of Long-Lasting Cocaine Hydrolases For Cocaine Overdose And Cocaine Use Disorder Treatment, Ting Zhang

Theses and Dissertations--Pharmacy

Cocaine is a plant-based illicit drug commonly involved in substance use disorder. Although cocaine overdose and cocaine use disorders cause adverse health consequences to individuals and the economic burden on their family and society, there are no FDA (Food and Drug Administration) approved medications for treatment. Recently, it has been recognized that delivery of cocaine hydrolase (CocH) is a promising therapeutic strategy. Human butyrylcholinesterase (hBChE), the primary enzyme involved in cocaine metabolism in human, have advantages over other candidates for the development of CocH. Previous studies in our laboratory have designed and characterized hBChE mutants that have ~4,000-fold improved catalytic …

Which Drugs Cause Cancer?, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Jarrod Bailey, PhD

Animal tests yield misleading results.

Which Drugs Cause Cancer?, Andrew Knight, Jarrod Bailey, Jonathan Balcombe

Andrew Knight, Ph.D.

Animal tests yield misleading results.