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Identification And Characterization Of Thegmha Gene Used For Inner Core Lipopolysaccharide Synthesis In Escherichia Coli, Joanna Susan Brooke
Identification And Characterization Of Thegmha Gene Used For Inner Core Lipopolysaccharide Synthesis In Escherichia Coli, Joanna Susan Brooke
Digitized Theses
Isolation, characterization and definition of the function of the gmhA locus in Escherichia coli could lead to a better understanding of the contribution of lipopolysaccharide (LPS) to bacterial disease. Such a description of the gmhA locus was the objective of the present studies. LPS mutants of Escherichia coli with defects in the biosynthesis and assembly of the heptose component of the core oligosaccharide display a shorter core that compromises the structural integrity of the outer membrane, resulting in a marked inability of these cells to grow in the presence of detergents, bile salts, and hydrophobic antibiotics. A heptoseless lipopolysaccharide E. …
Neurochemical Changes Following Stroke: Role In Neuroprotection And Cardiac Susceptibility, Raymond Tak Cheung
Neurochemical Changes Following Stroke: Role In Neuroprotection And Cardiac Susceptibility, Raymond Tak Cheung
Digitized Theses
The mechanisms mediating neuronal recovery and cardiovascular complications after ischemic stroke are not completely known. In these investigations, I examined changes in neuropeptides and a catecholamine synthesizing enzyme, tyrosine hydroxylase (TH), following middle cerebral artery occlusion (MCAO) in adult male Wistar rats.;Five days following MCAO, the immunoreactivity for TH and neuropeptide Y (NPY) increased in the insular cortex (IC) within the peri-infarct zone. NPY also increased ipsilaterally in the basolateral nucleus of the amygdala, whereas leucine-enkephalin, dynorphin and neurotensin increased ipsilaterally in the central nucleus of the amygdala. Sham MCAO was ineffective.;Neurochemical changes were assessed 5 days after localized excitotoxic …
Seed Colour Variation, Dormancy, And Seed Banks In The Bull Thistle, Cirsium Vulgare (Savi) Ten, Colleen Doucet
Seed Colour Variation, Dormancy, And Seed Banks In The Bull Thistle, Cirsium Vulgare (Savi) Ten, Colleen Doucet
Digitized Theses
The bull thistle, Cirsium vulgare (Savi) Ten. is listed as a noxious weed in Ontario and in Australia. It is widespread and found in many disturbed habitats such as roadsides, quarries, construction sites and pastures. Successful weeds are considered to demonstrate, among others, the following features: the production of a large number of small seeds, long-lived seeds, the presence of an efficient dispersal mechanism, and self-compatibility. Although seed production is substantial and Cirsium vulgare is self-compatible, the species has several characteristics that should constrain its demographic success. Seed dispersal is limited and in past studies, this species had been dismissed …
Cold Acclimation: A Complex Interaction Of Low Temperature, Light And The Redox State Of Photosystem Ii, Gordon R. Gray
Cold Acclimation: A Complex Interaction Of Low Temperature, Light And The Redox State Of Photosystem Ii, Gordon R. Gray
Digitized Theses
The process of cold acclimation refers to the physiological processes by which cold-tolerant plants such as cereals, when developed at low temperature, acquire freezing tolerance. Photosynthesis provides the energy required for these complex metabolic changes to take place. However, photosynthetic organisms must maintain a balance between energy input as a result of photochemical reactions and energy consumption through intersystem electron transport and the various biochemical reactions of cellular metabolism. Imbalances may be sensed by changes in the redox state of photosystem II (PSII), as this represents the rate-limiting step of photosynthetic electron transport. The redox state of PSII is sensitive …
Male Reproductive Success And The Mating System Of Bushy-Tailed Woodrats, Michael Graham Topping
Male Reproductive Success And The Mating System Of Bushy-Tailed Woodrats, Michael Graham Topping
Digitized Theses
Bushy-tailed woodrats are nocturnal cricetid rodents distributed throughout the mountainous regions of western North America. Despite a number of studies on the population ecology of this species, little is known about the behaviour of males during the breeding season.;I investigated the reproductive behaviour of male bushy-tailed woodrats in three ways. First, I examined the spatial distribution of individuals within a breeding population, using radiotelemetry and mark-recapture livetrapping. Both males and females exhibited considerable overlap with animals of both sexes, mean intersexual and intrasexual overlap values for each sex did not differ in two of the three years of study. This …
Properties And Regulation Of The Calcium Ion Pump In Heart And Skeletal Muscle Sarcoplasmic Reticulum, Cynthia Elaine Hawkins
Properties And Regulation Of The Calcium Ion Pump In Heart And Skeletal Muscle Sarcoplasmic Reticulum, Cynthia Elaine Hawkins
Digitized Theses
In heart and skeletal muscle, the sarcoplasmic reticulum (SR) plays a critical role in the contraction-relaxation cycle of the myocyte: a Ca{dollar}\sp{lcub}2+{rcub}{dollar} channel releases Ca{dollar}\sp{lcub}2+{rcub}{dollar} from SR into cytoplasm to trigger contraction, and a Ca{dollar}\sp{lcub}2+{rcub}{dollar} pump resequesters Ca{dollar}\sp{lcub}2+{rcub}{dollar} to cause relaxation. A major regulator of this cycle is {dollar}\rm Ca\sp{lcub}2+{rcub}{dollar}/calmodulin-dependent protein kinase (CaM kinase), which is known to phosphorylate and thereby activate the cardiac SR Ca{dollar}\sp{lcub}2+{rcub}{dollar} pump, Ca{dollar}\sp{lcub}2+{rcub}{dollar} channel and endogenous Ca{dollar}\sp{lcub}2+{rcub}{dollar}-pump inhibitor phospholamban. This thesis examines the Ca{dollar}\sp{lcub}2+{rcub}{dollar} pump and its regulation in different tissues (cardiac, slow-twitch and fast-twitch muscle SR: CMSR, SMSR and FMSR) and different stages in …
The Antioxidant Enzymes (Superoxide Dismutase, Catalase And Glutathione Peroxidase): Their Molecular Evolution And Regulation In Mice, Nicholas Joseph Schisler
The Antioxidant Enzymes (Superoxide Dismutase, Catalase And Glutathione Peroxidase): Their Molecular Evolution And Regulation In Mice, Nicholas Joseph Schisler
Digitized Theses
Reactive, oxygen derived free radicals are detoxified by an enzymatic pathway RA-5 which includes the enzymes superoxide dismutase (CuZn and Mn SOD), catalase (CAT) and glutathione peroxidase (GSH-Px). In an effort to understand the molecular evolution and antiquity of these enzymes, comparative techniques were developed for identification and visualization of protein family relationships. Analysis of amino acid sequence data indicated that these enzymes had expected phylogenetic relationships and that the two SOD enzymes were evolutionarily convergent. Multiple sequence alignments of the SOD, CAT and GSH-Px families of proteins were represented quantitatively and used to probe the Swiss-PROT database for proteins …
Osteopontin (Opn): Structural Analysis Of The Mouse Opn Gene And Functional Analysis Of The Opn Protein In Malignancy, Elke Ingeborg Behrend
Osteopontin (Opn): Structural Analysis Of The Mouse Opn Gene And Functional Analysis Of The Opn Protein In Malignancy, Elke Ingeborg Behrend
Digitized Theses
Osteopontin (OPN) is an integrin-binding cell adhesion protein, that is expressed in many normal cells and tissues, and that is associated with a number of pathological conditions, including cancer. The work presented in this thesis addresses both structural studies of the opn gene, and functional studies of the OPN protein, in an attempt to improve our understanding of OPN.;Two conflicting gene structures of the mouse opn gene had been reported that put into question the location of the promoter, the transcriptional start site, and exon 1 of the mouse opn gene. Analysis of the expressed messages predicted by the two …
Limbic Mechanisms Controlling Arterial Pressure, Stefanie Roder
Limbic Mechanisms Controlling Arterial Pressure, Stefanie Roder
Digitized Theses
Three series of experiments were done to investigate the output pathways from the central nucleus of the amygdala (ACe) involved in the control of arterial pressure. The first series of experiments provided the first demonstration that the arterial pressure responses elicited during stimulation of ACe were mediated via a direct pathway to the bed nucleus of the stria terminalis (BST). Microinjection of retrograde tract tracers into depressor regions of BST resulted in labelled neurons within predominantly the lateral subdivision of ACe. In addition, iontophoresis of the anterograde tract tracer PHA-L into cardiovascular responsive regions of ACe resulted in fiber and …
Regulation Of Corticosteroid-Binding Globulin Gene Expression, Xian Feng Zhao
Regulation Of Corticosteroid-Binding Globulin Gene Expression, Xian Feng Zhao
Digitized Theses
Corticosteroid-binding globulin (CBG) is a plasma glycoprotein that transports glucocorticoids and progesterone. Strain specific variations were found in rodent CBG coding sequences. Amino acid substitutions at positions 276 and 285 classify CBG of 8 rat inbred strains into 3 groups, and a {dollar}\rm Val\sp{lcub}285{rcub}\to Met{dollar} substitution seems to compensate the detrimental effect of the {dollar}\rm Met\sp{lcub}276{rcub}\to Ile{dollar} substitution on rat CBG steroid-binding affinity. Characterization of a mouse RIIIS/J CBG cDNA identified a single amino acid substitution (Lys{dollar}\sp{lcub}201{rcub}\to{dollar} Glu) that is responsible for the reduced steroid-binding affinity in RIIIS/J CBG. Exogenous glucocorticoids were shown to promote an increase of mouse CBG …
Comparative Reproductive Ecology Of Female Buffleheads (Bucephala Albeola) And Barrow's Goldeneyes (Bucephala Islandica) In Central British Columbia, Jonathan Edward Thompson
Comparative Reproductive Ecology Of Female Buffleheads (Bucephala Albeola) And Barrow's Goldeneyes (Bucephala Islandica) In Central British Columbia, Jonathan Edward Thompson
Digitized Theses
Waterfowl (Anseriformes) generally have high energetic costs for reproduction because they lay large, energy-rich eggs. Consequently, many temperate nesting ducks (Anatinae) occupy seasonally productive environments to meet nutritional requirements for egg production. However, ducks in the genus Bucephala often breed in unproductive boreal and montane regions. This study was conducted to investigate nutritional aspects of reproduction in female Buffleheads (Bucephala albeola) and Barrow's Goldeneyes (Bucephala islandica) breeding in central British Columbia.;Diet composition of breeding female Buffleheads and Barrow's Goldeneyes, which consisted primarily of benthic insects, was similar, providing support for the food defense hypothesis as an explanation for evolution of …
Parameters Controlling The Initiation Of Replication Of Coronavirus Jhm In Cells Of The Central Nervous System, Kishna Kumar Kalicharran
Parameters Controlling The Initiation Of Replication Of Coronavirus Jhm In Cells Of The Central Nervous System, Kishna Kumar Kalicharran
Digitized Theses
Parameters controlling the initiation of replication of the neurotropic Coranavirus JHMV were investigated to further elucidate the determinants conferring permissiveness or resistance of cells from the central nervous system. Two fines of enquiry pertaining to the early events of JHMV infection were investigated.;One aspect, the mechanism of JHMV penetration into host cells was examined with the fully permissive L-2 fibroblasts as the host. Several inhibitors including phenylarsine oxide, chlorpromazine, trifluoperazine, hypertonic solution and bafilomycin A1 affecting various stages of the endocytic pathway were used to affect penetration. These experimental approaches revealed that most probably JHMV is internalized through receptor-mediated endocytosis …
Human Placental Trophoblast As A Model For Tumor Progression, Nelson K. Khoo
Human Placental Trophoblast As A Model For Tumor Progression, Nelson K. Khoo
Digitized Theses
The human placenta is comprised of extravillous trophoblast (EVT) cells which invade the uterus and its vasculature establishing maternal-fetal exchange of key molecules. The mechanisms of in vitro EVT cell invasiveness are similar to those of malignant tumor cells but are regulated in situ by locally derived factors. This invasiveness is insufficient for malignancy. The goal of this laboratory is to transform normal EVT cells and induce premalignant, malignant and/or metastatic phenotypes to identify genetic changes relevant to tumor progression.;Two SV40 T antigen (Tag) transformed cell lines (long lived RSVT-2; immortal RSVT2/C) derived from the invasive first trimester EVT cell …
Expression Of Sodium Pump Subunit Genes During Mouse Preimplantation Development, Daniel James Macphee
Expression Of Sodium Pump Subunit Genes During Mouse Preimplantation Development, Daniel James Macphee
Digitized Theses
The Na,K-ATPase or sodium pump is an enzyme that is found in most animal cells. The enzyme pumps sodium and potassium ions against their concentration gradients and is hypothesized to be a mediator of fluid accumulation during mouse preimplantation development. The purpose of the present study was to determine, using reverse transcriptase-polymerase chain reaction (RT-PCR), whether all {dollar}\alpha\ (\alpha1,\ \alpha2,\ \alpha3,\ \alpha4{dollar}) and {dollar}\beta\ (\beta1{dollar} and {dollar}\beta{dollar}2) isoforms of the sodium pump were expressed during preimplantation development. Previous work by Watson and Kidder (1988) had shown that the {dollar}\alpha{dollar} subunit was localized to the basolateral domains of mural trophectoderm surrounding …
The Central Serotonergic And Cholinergic Systems As Activators Of The Electrocorticogram And Behavior, Hans Christian Dringenberg
The Central Serotonergic And Cholinergic Systems As Activators Of The Electrocorticogram And Behavior, Hans Christian Dringenberg
Digitized Theses
Experiments were performed on the role of ascending cholinergic and serotonergic electrocortical activating systems and their role in normal physiology and behavior. In urethane-anesthetized rats, electrocortical activation could be obtained by electrical stimulation of the amygdala, the dorsal raphe, the locus coeruleus area, the superior colliculus, and the orbitofrontal cortex. Activation elicited from the amygdala, the locus coeruleus area, and most orbitofrontal sites was abolished by systemic administration of the cholinergic-muscarinic antagonists scopolamine or atropine. Activation elicited from the dorsal raphe or superior colliculus was largely resistant to anti-muscarinic treatment but was abolished by methiothepin, a serotonergic antagonist. Infusions of …
Population Dynamics, Production And Resource Allocation In The Zebra Mussel, Dreissena Polymorpha, From The Lower Great Lakes, Canada, Margo Elizabeth Chase
Population Dynamics, Production And Resource Allocation In The Zebra Mussel, Dreissena Polymorpha, From The Lower Great Lakes, Canada, Margo Elizabeth Chase
Digitized Theses
Five populations of Dreissena polymorpha from three lakes (Lake St. Clair, Lake Erie and Lake Ontario) were examined to determine the population dynamics, reproductive cycle, secondary production and the allocation of resources to somatic tissue and shell, and gamete production.;Variation in life history characteristics, such as lifespan, age at first reproduction, maximum size and fecundity were observed both within and among sites, although the among-site variation was greater. The lifespan of D. polymorpha ranged from 2 to {dollar}>{dollar}4 years depending on the lake. The onset of sexual maturity was related to size, not age. Individuals became sexually mature between …
The Effects Of Cholecystokinin On Taste Reactivity In Rats: Evidence In Support Of A Satiety Effect, Lisa Anne Eckel
The Effects Of Cholecystokinin On Taste Reactivity In Rats: Evidence In Support Of A Satiety Effect, Lisa Anne Eckel
Digitized Theses
Cholecystokinin (CCK), a polypeptide gut-brain hormone, reduces food intake in a variety of species and across a number of experimental situations. By application of the taste reactivity test, the present thesis examined whether aversive side effects and/or alterations in palatability contribute to the anorectic effects of CCK in rats. Experiment 1 examined the ability of CCK to alter sucrose-elicited taste reactivity responses. Peripheral administration of CCK produced a dose-dependent reduction in ingestive responses without promoting an increase in aversive responses. Experiment 2 examined the ability of CCK to alter taste reactivity responses during oral water infusions. CCK treatment reduced the …
Some Physiological Effects Of Stress In The American Cockroach Periplaneta Americana (L), Shigui Liu
Some Physiological Effects Of Stress In The American Cockroach Periplaneta Americana (L), Shigui Liu
Digitized Theses
The effects of different forms of stress on the American cockroach, Periplaneta americana (L.) have been systematically examined. This study demonstrated that at least two stress-related events occurred in the haemolymph of the American cockroach. First, the data clearly indicated that a large increase in hypertrehalosemic hormones occurred in the haemolymph of stressed cockroaches. Secondly, proteolytic activity in the haemolymph of stressed cockroaches was greatly increased. The increase of both hypertrehalosemic hormones and proteolytic activity in the haemolymph appeared to be a non-specific response to different forms of stress, including chemical poisoning with lindane, immobilization, forced movement, starvation, and elevated …
Testing For Mate Choice And Competition In Convict Cichlids Using Ecologically Relevant Contexts, Diane Kathleen Urban
Testing For Mate Choice And Competition In Convict Cichlids Using Ecologically Relevant Contexts, Diane Kathleen Urban
Digitized Theses
Mate choice and intrasexual competition in convict cichlids, Cichlasoma nigrofasciatum, was investigated in the laboratory, during courtship, nest building, guarding eggs, and guarding fry. During courtship, females were expected to use male body size to indicate quality and to compete for large males. Females and newly introduced males were tested under two conditions: Treatment1--the males were similar in body length; and Treatment 2--one male was larger than the other two. No significant difference was found between treatments in the frequency of female proximity to males or in the frequency of female-female aggressive behaviour. However, the large male of Treatment 2 …
The Regulation Of A Type Iv Phosphodiesterase From L6 Myoblasts, A Thomas Kovala
The Regulation Of A Type Iv Phosphodiesterase From L6 Myoblasts, A Thomas Kovala
Digitized Theses
A potential role for cAMP in regulating the differentiation of myoblasts has lead to the examination of the components of the cAMP signalling system, in this case a cyclic nucleotide phosphodiesterase (PDE). A Type IV PDE isozyme was identified in L6 myoblasts using consensus sequence PCR primers, and its regulation by cAMP studied. Sequencing of RT-PCR products showed the presence of a Type IV PDE mRNA known as ratPDE 3.1. High levels of cAMP induced dramatic increases in the PDE mRNA levels as demonstrated by northern blot analysis. Run-off transcription experiments showed increased rates of transcription. L6 myoblasts which had …
Effects Of Industrial Effluents On Populations Of The Freshwater Mussel Lampsilis Radiata In The St Lawrence River, Lee Curtis Grapentine
Effects Of Industrial Effluents On Populations Of The Freshwater Mussel Lampsilis Radiata In The St Lawrence River, Lee Curtis Grapentine
Digitized Theses
The objective of this study was to assess the effects of industrial discharges, contaminated primarily with trace metals, on populations of Lampsilis radiata (Bivalvia: Unionidae) in the upper St. Lawrence River. Effects on shell growth were examined by (a) comparing growth curves derived from analyses of external annual rings of clams sampled from sites located upstream and downstream of four localized sources of discharges, and (b) measuring shell growth for one year from clams that were transplanted into contaminated and uncontaminated sites. Allozyme frequencies in clams from above and below discharges were determined for glucose-phosphate isomerase (GPI) and phosphoglucomutase (PGM), …
Evolutionary Dynamics At Two Loci Of The Human Genome As Assessed By Examination Of Nucleotide Sequence Diversity And Organization, Kathleen Allen Hill
Evolutionary Dynamics At Two Loci Of The Human Genome As Assessed By Examination Of Nucleotide Sequence Diversity And Organization, Kathleen Allen Hill
Digitized Theses
Accurate and comprehensive measurement of the extent and pattern of nucleotide diversity is necessary to refine theories on the dynamics of evolution. It is possible to determine the sequence of any genomic region for numerous individuals using the polymerase chain reaction (PCR) and associated techniques of DNA sequence analysis. The two regions of the human genome examined in this study were the third exon of the highly conserved (two major alleles) alcohol dehydrogenase, Adh2 locus and the second exon of the highly polymorphic (26 alleles) human leukocyte antigen, HLA-DQ{dollar}\beta{dollar}1 gene. Sequence information was determined from 25 individuals from Southwestern Ontario …
Transcriptional Regulation Of The Urea Cycle Enzyme Genes In The Liver Of Rana Catesbeiana Tadpoles During Spontaneous And Thyroid Hormone-Induced Metamorphosis, Yuqing Eugene Chen
Transcriptional Regulation Of The Urea Cycle Enzyme Genes In The Liver Of Rana Catesbeiana Tadpoles During Spontaneous And Thyroid Hormone-Induced Metamorphosis, Yuqing Eugene Chen
Digitized Theses
The ornithine urea cycle enzymes, carbamyl phosphate synthetase (CPS-1), ornithine transcarbamylase (OTC) and arginase, are liver-specific proteins. Their expression is coordinately activated during the metamorphosis of the Rana catesbeiana tadpole by thyroid hormone (TH), and their presence is critical for the shift of this amphibian from an aquatic, ammonotelic larva into a terrestrial, ureotelic adult. My studies were focused on analyzing the transcriptional regulation of the genes encoding these urea cycle enzymes and determining whether these genes were upregulated directly or indirectly by TH. With this thought in mind, I isolated and characterized the sequences in the promoter regions of …
Structure/Function Analyses Of Sex Hormone-Binding Globulin, Wayne Peter Bocchinfuso
Structure/Function Analyses Of Sex Hormone-Binding Globulin, Wayne Peter Bocchinfuso
Digitized Theses
Sex hormone-binding globulin (SHBG) is a homodimeric glycoprotein that transports sex steroids in the blood and extravascular fluids, such as seminiferous tubule fluid, where it is often referred to as androgen-binding protein (ABP). A cDNA for the human SHBG precursor polypeptide was expressed in mammalian cell lines. Recombinant human SHBG bound steroids with the same affinity and specificity as natural SHBG, and was immunologically indistinguishable from its natural counterpart. Site-directed mutagenesis of the SHBG cDNA was used to introduce amino acid substitutions that selectively removed glycosylation sites from SHBG. Analysis of these glycosylation mutants demonstrated that carbohydrates are not involved …
Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin
Developmental Potential Of Rat Myoblast Lineages, Christopher Louis Pin
Digitized Theses
Skeletal muscle consists of multinucleated fibres which are classified as slow (I) or fast (IIA, IIB, IIX) muscle fibre types which differ in their contractile properties and their expression of contractile protein isoforms. Individual muscles contain characteristic distributions of fibre types which can be identified based on their myosin heavy chain (MyHC) content. While classical studies have demonstrated that the fibre type composition of adult muscles can be altered by extrinsic factors (such as changes in the pattern of innervation), recent studies suggest that different fibre types may be formed from distinct myoblast lineages. The purpose of this study was …
The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu
The In Vitro Studies On Phage Mu Transposase, Zhenguo Wu
Digitized Theses
Bacteriophage Mu is one of the model systems to study DNA transposition. The availability of an in vitro soluble system greatly facilitates the dissection of the transposition mechanisms at the molecular levels. Several aspects of the in vitro mini-Mu DNA transposition have been dealt with in this thesis.;First, the flanking host DNA sequences on the strand cleavage step mediated by Mu transposase (Mu A protein) was investigated. We found that certain flanking host sequences could inhibit the strand cleavage step without affecting the earlier synapsis step. Furthermore, this cleavage defect could be overcome by the Mu B protein in the …
Neurotransmission Of Visceral Information In The Parabrachial Nucleus Of The Rat, Tarek Saleh
Neurotransmission Of Visceral Information In The Parabrachial Nucleus Of The Rat, Tarek Saleh
Digitized Theses
The parabrachial nucleus (PB) has been shown to be a major relay site for visceral afferents ascending through the ventrobasal thalamus and terminating in the insular cortex. The purpose of these investigations was to determine the neurotransmitter mechanisms in the PB involved in relaying visceral sensory information to the thalamus in the rat. Using electrophysiological techniques in the cloral hydrate anesthetised male Wistar rat, our results show that the visceral pathway from the PB to the thalamus appears to use two neuronal systems, one mediating the relay of specific visceral information via glutamatergic N-methyl D-aspartate (NMDA) receptors in the PB, …
The Function Of Sarcoplasmic Reticulum In The Aged Rat Heart, Ming Tao Jiang
The Function Of Sarcoplasmic Reticulum In The Aged Rat Heart, Ming Tao Jiang
Digitized Theses
The purpose of this project was to study the effect of aging on the regulation of Ca{dollar}\sp{lcub}2+{rcub}{dollar} by cardiac sarcoplasmic reticulum (SR) and its potential contribution to the age-related alterations in myocardial contractile performance in Fischer 344 rats.;In cardiac membranes enriched in SR (MSR) and its light (LSR) and heavy (HSR) subfractions fractionated by a sucrose density gradient, the rate of ATP-supported and oxalate-facilitated Ca{dollar}\sp{lcub}2+{rcub}{dollar} uptake was significantly reduced (24-50%) in the aged (26-30 months old) compared with that of the adult rats (6-8 months old). With aging, the Ca{dollar}\sp{lcub}2+{rcub}{dollar}-stimulated phosphoenzyme of the Ca{dollar}\sp{lcub}2+{rcub}{dollar} pumps was reduced in MSR, LSR …
The Putative Role Of Fatty Acids In The Activation Of Trehalose Synthesis In The Fat Body Of The Cockroach Periplaneta Americana L, Irshad Ali
Digitized Theses
Hypertrehalosemic hormones produced by the corpus cardiacum increase the concentration of several fatty acids in cockroach fat body trophocytes. The phospholipase A{dollar}\sb2{dollar} (PLA{dollar}\sb2){dollar} activator melittin has a similar effect. The fatty acids include palmitic, stearic, oleic and linoleic acid. The hormone mediated release of these fatty acids is blocked by the PLA{dollar}\sb2{dollar} inhibitors mepacrine and {dollar}\rho{dollar}-bromophenacyl bromide. These observations suggest that hormonal release of fatty acids, may be due to the activation of PLA{dollar}\sb2.{dollar};The increase in non-esterified fatty acids appears to be linked to the increase in trehalose efflux since sugar efflux is stimulated by stearic, oleic, linoleic and arachidonic …
Epidermal Growth Factor Regulation Of Porcine Oocyte Maturation And Cumulus Cell Expansion In Vitro, Balwant Singh
Epidermal Growth Factor Regulation Of Porcine Oocyte Maturation And Cumulus Cell Expansion In Vitro, Balwant Singh
Digitized Theses
The overall objective of this study was to investigate the role in vitro of epidermal growth factor (EGF) in the regulation of both nuclear and cytoplasmic maturation of the porcine oocyte, and in the expansion of cumulus cells.;Studies aimed at the induction of oocyte maturation and cumulus expansion revealed that EGF is a potent stimulant of the resumption of meiosis in the oocyte and that the addition of FSH, but not LH, to EGF further enhances its effect on germinal vesicle breakdown (GVBD). Both estradiol-17{dollar}\beta{dollar} (E{dollar}\sb2{dollar}) and androstenedione (A{dollar}\sb4{dollar}) inhibited FSH-stimulated GVBD, but had no effect on EGF-stimulated GVBD, suggesting …