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East Tennessee State University

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Full-Text Articles in Pharmacology, Toxicology and Environmental Health

Validation Of The 40 Hz Auditory Steady State Response As A Pharmacodynamic Biomarker Of Evoked Neural Synchrony, Muhammad Ummear Raza Aug 2022

Validation Of The 40 Hz Auditory Steady State Response As A Pharmacodynamic Biomarker Of Evoked Neural Synchrony, Muhammad Ummear Raza

Electronic Theses and Dissertations

Schizophrenia is a troubling and severe mental illness that is only incompletely treated by currently available drugs. New drug development is hindered by a scarcity of functionally relevant pharmacodynamic biomarkers that are translatable across preclinical and human subjects. Although psychosis is a major feature of schizophrenia, cognitive and negative symptoms determine the long-term functional outcomes for patients. Stimulus-evoked neural synchrony at gamma (~ 40 Hz) frequency plays an important role in the processing and integration of sensory information. Not surprisingly, schizophrenia patients show deficits in gamma oscillations. NMDA receptor (NMDAR) activation on fast-spiking parvalbumin-positive interneurons is deemed important for the …


Dibutyl Amine Detection, Quantification, And Removal With Iron(Ii)Tetrasulfophthalocyanine (Fetspc), Kyle Bittner Aug 2022

Dibutyl Amine Detection, Quantification, And Removal With Iron(Ii)Tetrasulfophthalocyanine (Fetspc), Kyle Bittner

Electronic Theses and Dissertations

Pesticide testing is of practical interest in various areas of today’s world due to their prevalence and toxicity. These areas include agriculture, environmental, chemical plants, and many others. Herbicides, like Roundup, contain secondary amines such as glyphosate. The ability to detect secondary amines could offer a method for glyphosate detection in agricultural and environmental samples. Secondary amines can interact with metal complexes through electron charge transfer. Such interactions can cause a change in the metal’s electron configuration and energy state and can be seen in the UV-Vis spectrum. Metal phthalocyanines (MPc’s) and other organometallic complexes have been of interest for …


Early Detection Of Atypical Motor And Neurobehavior Of Infants At Risk Secondary To Opioid Exposure: A Prospective Study, Kara Boynewicz May 2022

Early Detection Of Atypical Motor And Neurobehavior Of Infants At Risk Secondary To Opioid Exposure: A Prospective Study, Kara Boynewicz

Electronic Theses and Dissertations

Prenatal opioid exposure has been studied in relation to infants' medical outcomes. However, large gaps exist in the literature supporting early identification of atypical neurobehavior and motor development of infants with prenatal opioid exposure. The purpose of the study was to investigate whether prenatal opioid exposure has a negative influence on a newborn infant’s neurobehavior and motor development to aid in the early identification of potential delays. Using a prospective quasi experimental design, infants motor development using the Test of Infant Motor Performance (TIMP) and neurobehavior using the NICU Neonatal Network Scale (NNNS) was assessed on 58 infants in a …


Behavioral Effects And Neurobiological Mechanisms Of 3-Aminobenzimide In A Rodent Model Of Chronic Psychological Stress, Liza Wills May 2022

Behavioral Effects And Neurobiological Mechanisms Of 3-Aminobenzimide In A Rodent Model Of Chronic Psychological Stress, Liza Wills

Electronic Theses and Dissertations

Major depressive disorder (MDD) is a leading cause of disability worldwide, with a lifetime prevalence rate of approximately 20%. Inadequate pharmacological treatment methods for MDD are a significant debilitating factor. Patient estimates suggest that the treatment resistance rate for pharmacological interventions is over 30%. Postmortem analyses of human tissue of individuals diagnosed with MDD have shown an increase in Poly (ADP-ribose) polymerase 1 (PARP-1) mRNA gene expression in prefrontal cortical white matter when compared to psychiatrically normal brain tissue. In order to further investigate this issue, the present study used the social defeat stress/chronic unpredictable stress (SDS + CUS) rodent …


Operatic Mysticisms: Mountains, Deserts, Waterscapes, Andrew Demczuk May 2022

Operatic Mysticisms: Mountains, Deserts, Waterscapes, Andrew Demczuk

Electronic Theses and Dissertations

Operatic Mysticisms: Mountains, Deserts, Waterscapes examines the ways we encounter environments as readers/viewers of operas, literature, film, and sound recordings, and how each medium requires different detail-gathering techniques. Respective to the previously mentioned mediums, Sun & Sea (2017), Mount Analogue (1952), El Mar La Mar (2017), and Energy Field (2010) are analyzed by engaging with environmental media studies and invention. Reflecting the nature of each landscape—summits of mountains, aporias of deserts, and mysteries of waterscapes—an elemental approach is taken in investigating how these spaces may be noticed, internalized, recorded, and traversed by both the artist and viewer. …


Effects Of Respiratory Perturbations On Aging And Healthspan In Daphnia Magna, Millicent Nkiruka Ekwudo May 2021

Effects Of Respiratory Perturbations On Aging And Healthspan In Daphnia Magna, Millicent Nkiruka Ekwudo

Electronic Theses and Dissertations

Aging is a degenerative process characterized by a decline in physiological functions and cellular activities. Environmental and pharmacological interventions affecting longevity pathways have been extensively studied in model organisms. This study investigated the effect of chronic mild intermittent hypoxia (4 mg O2/L) or mild mitochondrial uncoupling with three doses of 0 (control), 0.1, 1, and 5 μM of 2,4-Dinitrophenol (DNP), on life history and gene expression in four clones of Daphnia magna. Interestingly, clones from intermittent ponds displayed better tolerance to hypoxia and DNP. Although neither treatments extended longevity, hypoxia increased fecundity and body size, and decreased food consumption and …


Potential Toxicity Of Silver Nanoparticles To Microbial Communities And Macroinvertebrates, Joseph Kusi Aug 2020

Potential Toxicity Of Silver Nanoparticles To Microbial Communities And Macroinvertebrates, Joseph Kusi

Electronic Theses and Dissertations

Silver nanoparticles (AgNPs) are the most common nanomaterials incorporated in commercial products due to their antimicrobial activity. Recently, AgNPs were detected in surface waters suggesting the potential for bioavailability in the aquatic receptor organisms. This dissertation research attempts to understand the potential toxicity of AgNPs on water quality indicators, focusing on the microbial community and amphipods. This study evaluated whether: (1) the antimicrobial properties of AgNPs pose potential risks to microbial communities in pathogen impaired streams; (2) AgNPs can cause a shift in functional diversity and metabolic fingerprinting of microbial communities; (3) survival and growth of Hyalella azteca (amphipods) could …


The Role Of Cyp2a5 In Cadmium-Induced Liver Injury, Julia Salamat Dec 2018

The Role Of Cyp2a5 In Cadmium-Induced Liver Injury, Julia Salamat

Electronic Theses and Dissertations

Cadmium is present in food and groundwater. Tobacco smoking and occupational exposure are also major sources for cadmium. Cadmium is primarily accumulated in liver, a major organ metabolizing exogenous chemicals. Chemical metabolism may cause detoxification, but it can also cause bio-activation resulting in liver damage. Cytochrome P450s (CYP) are major liver metabolism enzymes, and cadmium chloride (CdCl2) can induce CYP2A5 in mice. We examined the effect of CYP2A5 on CdCl2-induced liver injury using CYP2A5-knockout (cyp2a5-/-) mice. The cyp2a5-/- mice and their control WT mice were injected CdCl2 intraperitoneally at 5 mg/kg body weight, respectively, to induce liver injury. …


Hiv Integrase Inhibitor Pharmacogenetics And Clinical Outcomes: An Exploratory Association Study, Derek E. Murrell Aug 2018

Hiv Integrase Inhibitor Pharmacogenetics And Clinical Outcomes: An Exploratory Association Study, Derek E. Murrell

Electronic Theses and Dissertations

As HIV is now primarily a chronic condition, treatment is given life-long with changes as necessitated by alterations in tolerability and efficacy. Thus, personalized medicine may be useful in the prevention of unnecessary drug exposure and avoidable side effects. Three of the four currently available HIV integrase strand transfer inhibitors (INSTIs), raltegravir, elvitegravir, and dolutegravir, are widely utilized antiretrovirals in the USA and exhibit variations in outcomes among subjects. To interrogate differences among subjects receiving these drugs, we investigated the association of several single nucleotide polymorphisms (SNPs) with drug exposure, clinical outcomes, and subject-reported adverse events. HIV+ adults (≥18 years …


The Combined Neuropharmacology And Toxicology Of Major 'Bath Salts' Constituents Mdpv, Mephedrone, And Methylone, Serena Allen May 2018

The Combined Neuropharmacology And Toxicology Of Major 'Bath Salts' Constituents Mdpv, Mephedrone, And Methylone, Serena Allen

Electronic Theses and Dissertations

The synthetic cathinones, 3,4- methylenedioxypyrovalerone (MDPV), 4-methylmethcathinone (mephedrone), and 3,4- methylenedioxymethcathinone (methylone), gained worldwide notoriety as the psychoactive components of ‘bath salts;’ a marketing term used to circumvent federal drug laws and permit their legal sale. Previous studies have shown that these drugs share pharmacological characteristics with cocaine and the amphetamines, however, descriptions of their neurotoxic properties are limited. Moreover, while forensic analysis has revealed that the most frequently abused bath salts ‘brands’ contain binary and ternary mixtures of MDPV, mephedrone, and methylone, the majority of preclinical research has focused on explicating the individual effects of these drugs. Therefore, the …


Enemy Exacerbation: Effects Of Predator Stress On Sulfate Lethality In Freshwater Amphipods (Gammarus Minus), Trevor Chapman Aug 2017

Enemy Exacerbation: Effects Of Predator Stress On Sulfate Lethality In Freshwater Amphipods (Gammarus Minus), Trevor Chapman

Electronic Theses and Dissertations

Predator cues can influence how aquatic organisms respond to anthropogenic contaminants. This study examined the effects of predator cues on behavior, metabolic rate, and sulfate (as Na2SO4) toxicity in amphipods (Gammarus minus). Predator cues included alarm cue (macerated conspecifics) and kairomone from mosquitofish (Gambusia affinis). Amphipods decreased activity and increased time in refuge when exposed to alarm cue, and increased time in refuge when exposed to kairomone. While median lethal concentrations (96-h LC50) were not influenced by predator cues, analysis of dose response curves indicated that kairomone exposure increased amphipod …


Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett May 2017

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …


Pharmacokinetics, Tissue Distribution, Synergistic Activity, And Antitumor Activity Of Two Isomeric Flavones, Crystal L. Whitted Dec 2016

Pharmacokinetics, Tissue Distribution, Synergistic Activity, And Antitumor Activity Of Two Isomeric Flavones, Crystal L. Whitted

Electronic Theses and Dissertations

Flavonoids are polyphenolic secondary metabolites found in plants that have bioactive properties including antiviral, antioxidant, and anticancer. Two isomeric flavone were extracted from Gnaphalium elegans and Achyrocline bogotensis, plants used by the people from the Andean region of South America as remedies for cancer. 5,7-dihydroxy-3,6,8-trimethoxy-2-phenyl-4H-chromen-4-one (5, 7–dihydroxy- 3, 6, 8 trimethoxy flavone/ flavone A) and 3,5-dihydroxy-6,7,8-trimethoxy-2-phenyl-4H-chromen-4-one (3, 5–dihydroxy-6, 7, 8–trimethoxy flavone/ flavone B) have shown antineoplastic activity against colon cancer cell lines dependent upon their differentiation status. Pharmacokinetic studies reported herein were used to determine dosing for antitumor assays, as well as determine target tissue concentration. These included the …


An Analysis Of The Interaction Of Methylphenidate And Nicotine In Adolescent Rats: Effects On Bdnf, Elizabeth D. Freeman Aug 2015

An Analysis Of The Interaction Of Methylphenidate And Nicotine In Adolescent Rats: Effects On Bdnf, Elizabeth D. Freeman

Electronic Theses and Dissertations

This investigation was an analysis of the interaction of adolescent exposure to methylphenidate (MPH; trade name: Ritalin) on nicotine sensitization and conditioned place preference (CPP) in a rodent model and underlying mechanisms of this effect. Animals were treated IP with 1 mg/kg MPH or saline using a ―school day‖ regimen of five days on, two days off, from postnatal day (P) 28-50. During the final two weeks of MPH treatment, animals were either behaviorally sensitized to nicotine (0.5 mg/kg free base) or saline for 10 days, or conditioned to nicotine or saline using the CPP behavioral paradigm. In addition, three …


Evaluation Of Colloidal Stability And Ecotoxicity Of Metal-Based Nanoparticles In The Aquatic And Terrestrial Systems, Lok R. Pokhrel May 2013

Evaluation Of Colloidal Stability And Ecotoxicity Of Metal-Based Nanoparticles In The Aquatic And Terrestrial Systems, Lok R. Pokhrel

Electronic Theses and Dissertations

Intrinsic to the many nano-enabled products are atomic-size multifunctional engineered nanomaterials, which upon release contaminate the environments, raising considerable health and safety concerns. This Ph.D. dissertation is designed to investigate (i) whether metals or oxide nanoparticles are more toxic than ions, and if MetPLATETM bioassay is applicable as a rapid nanotoxicity screening tool; (ii) how variable water chemistry (dissolved organic carbon (DOC), pH, and hardness) and organic compounds (cysteine, humic acid, and trolox) modulate colloidal stability, ion release, and aquatic toxicity of silver nanoparticles (AgNP); and (iii) the developmental responses of crop plants exposed to Ag- or ZnO- (zinc …


Application Of Multivariate Statistical Methodology To Model Factors Influencing Fate And Transport Of Fecal Pollution In Surface Waters, Kimberlee K. Hall Aug 2012

Application Of Multivariate Statistical Methodology To Model Factors Influencing Fate And Transport Of Fecal Pollution In Surface Waters, Kimberlee K. Hall

Electronic Theses and Dissertations

Degraded surface water quality is a growing public health concern. While indicator organisms are frequently used as a surrogate measure of pathogen contamination, poor correlation is often observed between indicators and pathogens. Because of adverse health effects associated with poor water quality, an assessment of the factors influencing the fate and transport of fecal pollution is necessary to identify sources and effectively design and implement Best Management Practices (BMPs) to protect and restore surface water quality. Sinking Creek is listed on the State of Tennessee’s 303D list as impaired due to pathogen contamination. The need to address the listing of …


An Evaluation Of Coating Material Dependent Toxicity Of Silver Nanoparticles, Thilini Upekshika Silva Dec 2011

An Evaluation Of Coating Material Dependent Toxicity Of Silver Nanoparticles, Thilini Upekshika Silva

Electronic Theses and Dissertations

Silver nanoparticles (AgNPs) synthesized using numerous types of coating materials may exhibit different toxicity effects. The study evaluated coating material dependent toxicity by selecting 3 types of AgNP synthesis methods with different coating materials (citrate, polyvinyl pyrrolidone, and branched polyethyleneimine, coated AgNPs as citrate-AgNPs, PVP-AgNPs, and BPEI-AgNPs respectively). Two acute aquatic toxicity tests were performed; 48hr D. magna and MetPLATE E. coli toxicity tests. Significantly different toxicity effects were observed in D. magna test exhibiting lethal median concentrations (LC50) for citrate-AgNPs, PVP-AgNPs, and BPEI AgNPs respectively as, 2.7, 11.2, and 0.57μg/L. Median inhibitory concentrations (EC50) for MetPLATE tests were 1.27, …


Urinary Excretion Of (1-3)-Beta-D-Glucans., Debra K. Head Dec 2008

Urinary Excretion Of (1-3)-Beta-D-Glucans., Debra K. Head

Electronic Theses and Dissertations

(1→3)-β-D-Glucans are carbohydrate polymers that are present in the cell wall of various fungi and bacteria; they are pathogen associated molecular patterns that circulate during infection and modulate immunity. Our laboratory has previously established the pharmacokinetics of intravenously and orally administered glucans; the present studies investigated the renal excretion of (1→3)-β-D-glucans following intravenous and oral administration. Three fluorescently-labeled glucans were administered to adult male rats in the presence or absence of toxic challenge. Urine specimens were collected and analyzed by fluorescence spectroscopy, size-exclusion chromatography and GPC/MALLS. 71 ± 3% of fluorescence remained in the >5K MWCO fraction; this fraction showed …


Previous Spatial Memory Training And Nicotine Administration Alleviates Cognitive Deficits Produced By Medial Frontal Cortex Lesions In Rats., Rachel L. Norris May 2006

Previous Spatial Memory Training And Nicotine Administration Alleviates Cognitive Deficits Produced By Medial Frontal Cortex Lesions In Rats., Rachel L. Norris

Electronic Theses and Dissertations

Rats were administered nicotine (0.3 mg/kg) for 11 consecutive days before and after an electrolytic medial frontal cortex lesion. Behavioral testing was arranged so that the rats were tested on the RAM 1 day after drug administration followed by behavioral testing on the MWT 19 days after drug treatment, or tested on the MWT 1 day after drug administration followed by testing on the RAM4 days after drug treatment. Results of MWT testing showed that regardless of the drug/behavioral testing interval, lesioned rats given nicotine demonstrated enhancement relative to saline-treated animals. Results of RAM testing showed that nicotine improved performance …


Signaling Mechanisms For Muscarinic Receptor-Mediated Coronary Vasoconstriction In Isolated Rat Hearts, Yi Zhang Aug 1999

Signaling Mechanisms For Muscarinic Receptor-Mediated Coronary Vasoconstriction In Isolated Rat Hearts, Yi Zhang

Electronic Theses and Dissertations

The signaling mechanisms for muscarinic receptor-mediated vasoconstriction in coronary resistance arteries were studied in KCl-arrested isolated rat hearts perfused at a constant flow rate. The cholinergic agonists acetylcholine and bethanechol were given by bolus injection or constant infusion. The coronary vascular resistance was monitored by measuring the changes in perfusion pressure. The selective muscarinic agonist bethanechol caused a similar vasoconstrictor response as ACh, but with less potency and efficacy. Bolus injection of bethanechol evoked a phasic vasoconstriction in a dose-dependent manner, while infusion of bethanechol evoked a tonic vasoconstriction without producing tachyphylaxis. Coronary vascular responses to bethanechol were further examined …


In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long Aug 1998

In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long

Electronic Theses and Dissertations

An in vitro model was used to assess the effect of cocaine and its metabolites on the umbilical artery. Objectives were to pharmacologically confirm the presence of adrenergic innervation using tyramine, evaluate the ability of cocaine, benzoylecgonine, norcocaine and cocaethylene to potentiate vasoconstriction by serotonin and norepinephrine, examine the ability of ketanserin to block the enhanced vasoconstriction produced by cocaine, and determine displacement of 3 H-ketanserin by serotonin, norepinephrine, tyramine and mianserin. The vasoconstrictive effect of tyramine (100 μM) was enhanced in the presence of cocaine by 257%. Vasoconstrictive effects of serotonin and norepinephrine were significantly enhanced by cocaine by …


Comparison Of Beta-Adrenoceptor Coupled Camp Production In Cultured Human Mononuclear Leukocytes And Myometrial Cells, Yu-Li Liu Dec 1997

Comparison Of Beta-Adrenoceptor Coupled Camp Production In Cultured Human Mononuclear Leukocytes And Myometrial Cells, Yu-Li Liu

Electronic Theses and Dissertations

$\beta\sb2$-Adrenoceptor ($\beta\sb2$-AR) agonists, such as terbutaline, are used as tocolytic agents in the treatment of preterm labor. $\beta$-Adrenoceptor stimulation relaxes myometrium through specific receptors coupled through Gs to adenylyl cyclase (AC) that catalyzes the conversion of ATP to cAMP. The purpose of this study was to compare $\beta$-adrenoceptors and cAMP production in cultured human leukocytes and myometrial cells, and to determine the importance of $\beta$-adrenoceptors and cAMP production in isoproterenol-induced myometrial relaxation. $\sp{125}$I-iodopindolol was used to assess $\beta$-adrenoceptor affinity and number cAMP levels were analyzed before and after stimulation by isoproterenol, AlF$\sb4\sp-$, forskolin, and PGE$\sb1$. Isometric recording was used to …


Persistent Oral Dyskinesias Induced By Long-Term Haloperidol Treatment Is Dissociated From Changes In Neostriatal B(Max) And Mrna Content For Dopamine D(2) Receptors, Nuoyu Huang May 1995

Persistent Oral Dyskinesias Induced By Long-Term Haloperidol Treatment Is Dissociated From Changes In Neostriatal B(Max) And Mrna Content For Dopamine D(2) Receptors, Nuoyu Huang

Electronic Theses and Dissertations

Due to the presumed associations of dopamine (DA) receptor supersensitivity phenomena in both long-term neuroleptic-treated tardive dyskinetic rats and neonatal 6-hydroxydopamine (n6-OHDA)-lesioned rats, we studied the influence of haloperidol on n6-OHDA-lesioned rats. At 3 days after birth rats received 6-OHDA-HBr (200 $\mu$g, bilateral intracerebroventricularly; desipramine pretreatment, 20 mg/kg, 1h) or vehicle. Two months later haloperidol (1.5/kg/day $\times$ 2 days/week for 4 weeks, then 1.5 mg/kg/day, every day for 10 months) was added to the drinking water. Spontaneous oral activity of intact and n6-OHDA-lesioned rats receiving haloperidol was reached and maintained at significantly higher levels after 15 weeks of haloperidol treatment. …


Indomethacin Reduces Splenic Red Pulp Macrophage Populations In Female New Zealand White Rabbits, Thane S. Thurmond May 1995

Indomethacin Reduces Splenic Red Pulp Macrophage Populations In Female New Zealand White Rabbits, Thane S. Thurmond

Electronic Theses and Dissertations

In an effort to elucidate the mechanism by which indomethacin (IN) attenuates the stimulatory effect of estradiol (E$\sb2$) on rabbit splenic red pulp macrophages (RPM), thirty-nine female New Zealand White rabbits were divided into 10 groups: ovariectomized (OVX), OVX/IN at 0.1 and 5.0 mg/kg body weight (bw)/day; sham OVX (SOVX), SOVX/IN at 0.1 and 5.0 mg/kg bw/day; OVX/25 mg E2, OVX/25 mg E$\sb2$/IN at 0.1 and 5.0 mg/kg bw/day; intact Control. Quantitative changes in RPM population in response to the treatments were measured using a 0 to 4 histologic grading scale. Estradiol treatment resulted in increased RPM grade when compared …


Denervation Supersensitivity Of The Rat Vas Deferens: A Role For Protein Kinase C, Sonny T. Abraham May 1994

Denervation Supersensitivity Of The Rat Vas Deferens: A Role For Protein Kinase C, Sonny T. Abraham

Electronic Theses and Dissertations

A role for protein kinase C (PKC) in the denervation-induced supersensitivity of the rat vas deferens was investigated. Chronic, surgical denervation of the rat vas deferens (up to 8 days) resulted in tissues that produced enhanced contractile responses to norepinephrine (NE) in isolated organ baths. Single challenges of NE (10 $\mu$M) produced 0.6 $\pm$ 0.1 g of maximal tension in the control vas whereas in the paired, denervated tissue 2.2 $\pm$ 0.3 g of tension was recorded (n = 6). Cumulative concentration-effect curves to NE produced in the denervated vas deferens were shifted 18-fold to the left of the control …


Differential Role Of The Endothelium In Regulating Microvascular Blood Flow, Tao Tang May 1994

Differential Role Of The Endothelium In Regulating Microvascular Blood Flow, Tao Tang

Electronic Theses and Dissertations

The vascular endothelial cell (EC) plays an important role in regulating vascular tone and local blood flow by sensing chemical and mechanical stimuli on the vascular wall and releasing a host of vasoactive substances upon activations of endogenous or exogenous vasoactive substances. The central hypothesis is that local control of blood now and autoregulatory behavior in the microcirculation is distinctive at different levels of the vasculature and is dependent on the cellular activities of the EC and its interaction with the local environment. The in vivo as well as the ex vivo, flow-controlled preparations of the hamster cheek pouch were …


Characterization Of The Vasoactivity Of Tachykinins In Isolated Rat Kidney: Functional Studies And In Vitro Receptor Autoradiography, Yuejin Chen May 1994

Characterization Of The Vasoactivity Of Tachykinins In Isolated Rat Kidney: Functional Studies And In Vitro Receptor Autoradiography, Yuejin Chen

Electronic Theses and Dissertations

Although tachykinins have potent vascular actions, their effect on renal resistance blood vessels is currently unknown. The vasoactive properties of tachykinins and related analogs were assessed in isolated perfused rat kidney. At a basal perfusion pressure (PP) of 75 $\pm$ 6 mm Hg (n = 5), bolus injections of substance P (SP) had no significant vasoactive effect. Following a sustained increase in baseline PP (134 $\pm$ 10 mm Hg) produced by phenylephrine (1 $\mu$M), SP evoked a dose-dependent increase in PP. The largest dose of SP increased PP by 60 $\pm$ 5 mm Hg. The vasoconstrictor response to SP was …


Co-Sensitization Of Dopamine And Serotonin Receptors Occurs In The Absence Of A Change In The Dopamine D1 Receptor Complex After A Neonatal 6-Ohda Lesion, Li Gong Dec 1993

Co-Sensitization Of Dopamine And Serotonin Receptors Occurs In The Absence Of A Change In The Dopamine D1 Receptor Complex After A Neonatal 6-Ohda Lesion, Li Gong

Electronic Theses and Dissertations

To test whether SKF 38393 could ontogenetically sensitize dopamine (DA) D$\sb1$ receptors and whether this sensitization would be associated with biochemical changes, intact and neonatal 6-hydroxydopamine (6-OHDA)-lesioned rats (200 $\mu$g i.c.v.) were treated daily from birth with SKF 38393 (3.0 mg/kg i.p. x 28 days) or its vehicle. In DA D$\sb1$ neonatally sensitized 6-OHDA rats, enhanced locomotor responses were observed with the first SKF 38393 challenge dose (3.0 mg/kg i.p.) at 6 weeks. This response increased further with weekly SKF 38393 treatments. Enhanced stereotyped behaviors were seen in both lesioned and sensitized rats at 8 weeks. There was no change …


The Effect Of Trimethyltin On The Cholinergic System Of The Rat Hippocampus, Richard L. Cannon Dec 1992

The Effect Of Trimethyltin On The Cholinergic System Of The Rat Hippocampus, Richard L. Cannon

Electronic Theses and Dissertations

Trimethyltin (TMT) is a neurotoxin occurring in the environment. Exposure to (TMT) is known to destroy specific neuronal components of the hippocampus in the rat and to cause clinical symptoms in exposed humans, including mnemonic deficits, that indicate hippocampal involvement. In addition to hippocampal cell loss TMT causes significant increases in cholinergic markers such as acetylcholinesterase (AChE) stain density and choline acetyltransferase (ChAT) activity in the hippocampus of rats. However, despite these observations the effect of TMT on hippocampal cholinergic system has not been investigated in detail. The purpose of the present study was to elucidate more fully the consequences …


Nitrogen Dioxide Reaction With Proteins: Evidence For Peptide Bond Cleavage At Lysine Residues, Darryl B. Hood May 1991

Nitrogen Dioxide Reaction With Proteins: Evidence For Peptide Bond Cleavage At Lysine Residues, Darryl B. Hood

Electronic Theses and Dissertations

Nitrogen dioxide (NO$\sb2$), an air pollutant produced by burning fossil fuels and a component of cigarette smoke, is thought to contribute to the pathogenesis of pulmonary diseases, such as emphysema. To gain information on the mechanism by which NO$\sb2$ damages the lung, in vitro exposures of $\alpha\sb1$-proteinase inhibitor ($\alpha\sb1$-PI), elastin, bovine serum albumin (BSA), human serum albumin (HSA) and synthetic poly-L-lysine were performed. A genetic deficiency of $\alpha\sb1$-PI predisposes humans to emphysema and NO$\sb2$ has been hypothesized to damage $\alpha\sb1$-PI, which would leave proteases such as human neutrophil elastase, (HNE) free to attack lung structural proteins. The ability of $\alpha\sb1$-PI …