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The effects of choline availability from gestation to early development on brain and retina function and phospholipid in a mice modelAlashmali, Shoug 09 September 2013 (has links)
Choline is known to be essential for brain development and neural function, but its impact on the retina, as a type of neural tissue, is unknown. This study examined the effects of choline during fetal development on membrane phospholipid (PL) compositions and functions in neural tissues, brain and retina. Pregnant C57 BL/6 mice were fed one of the 4 choline modified diets from gestation to early development: i) deficient (Def, 0g/kg), ii) control (Cont, 2.5g/kg), iii) supplemented with choline chloride (Cho, 10g/kg), iv) supplemented with egg phosphatidylcholine (PC) (PC, 10g/kg). On postnatal day (PD) 7, pups were culled to 4 from each dam, and kept on the same respective diets until 45 PD. On PD 35, memory function was measured by Morris water maze and on PD 45, retina function by an electroretinogram. Brain and retina were obtained for PL analysis by 31P NMR. Animals on the Def and PC diets were lower in body weights on PD 7, in comparison to the other two groups. While the Def group caught up in weights to its Cont counterparts, the PC group’s weight stayed consistently low until PD 45 (P<0.03). As for brain function, Cho and PC supplemented groups showed enhanced cued learning task, and spatial memory abilities, respectively, whereas the Def group showed the poorest memory recollection (P<0.05). The ERG amplitudes of rod driven photoreceptors and inner neural cell functions were significant (P<0.05) in the following order: Cont > Def > PC > Cho, at all light intensities, without reaching statistical significances in cone-driven responses. There were no differences in major PL compositions in the brain and retina. PC enriched group had increased subclasses of ether PL, PEaa and PCaa in the brain. These results indicate that while the addition of choline supplementation is beneficial for fetal brain development and function during early developmental stages, its contributions in the retina were minor. The effect of choline to the membrane PL structure was negligible for the stage of development in the given experimental design.
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Choline sulfate utilization by Penicillium chrysogenumHernandez, Eovaldo, January 1966 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1966. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 42-43.
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Structural modifications of the liver and kidneys of rats fed low-protein and low-choline diets and the response to supplementationNiño-Herrera, Hipolito, January 1958 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1958. / Typescript. Abstracted in Dissertation abstracts, v. 18 (1958) no. 3, p. 778. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
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Osmoregulation in coagulase-positive and coagulase-negative staphylococciKaenjak, Anisa. Wilkinson, Brian J. January 1993 (has links)
Thesis (Ph. D.)--Illinois State University, 1993. / Title from title page screen, viewed March 6, 2006. Dissertation Committee: Brian J. Wilkinson (chair), Herman E. Brockman, H. Tak Cheung, Radheshyam K. Jayaswal, Robert L. Preston. Includes bibliographical references (leaves 162-176) and abstract. Also available in print.
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Postnatal supplemental choline facilitates extinction of fear in adolescent rats /Hakkal, Natasha Chandini. January 2009 (has links)
Thesis (Honors)--College of William and Mary, 2009. / Includes bibliographical references (leaves 22-25). Also available via the World Wide Web.
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The development of enzyme electrodes for neurophysiologyGalley, Peter Timothy January 1991 (has links)
No description available.
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Characterization of S-Adenosyl-L-Methionine Phosphomethylethanolamine N-Methyltransferase from SpinachDhadialla, Sharonpal Kaur 11 1900 (has links)
In response to salinity and drought, some higher plants accumulate the secondary
metabolite glycinebetaine which functions as a compatible osmolyte (Rhodes and
Hanson, 1993). Choline, a precursor of glycinebetaine (Rhodes and Hanson, 1993), is
also a component of a primary metabolite phosphatidylcholine, an ubiquitous membrane
phospholipid (Moore, 1982). In leaves of the glycinebetaine accumulator spinach,
choline is synthesized as phosphocholine (PCho) and PCho is synthesized by three
sequential N-methylations of phosphoethanolamine (PEA) ~ phosphomethyl-EA
(PMEA) ~ phosphodimethyl-EA (PDEA) ~ PCho. The methyl group donor is Sadenosyl-
L-methionine, SAM (Summers and Weretilnyk, 1993). The enzyme SAM:
PMEA N-methyltransferase (PMEAMeT) is suggested to N-methylate PMEA ~ PDEA
~ PCho (Weretilnyk and Summers, 1992).
A four-step strategy was developed for the partial purification of PMEAMeT on
the basis of PMEA-dependent methylations (PMEAMeT activity) that involved the
extraction of soluble leaf protein, ammonium sulfate precipitation, and column
chromatography on DEAE Sepharose, Phenyl Sepharose and High Q Anion matrices.
PDEA-dependent methylating activity co-purified with PMEAMeT activity which
suggested PMEAMeT may N-methylate PMEA ~ PDEA ~ PCho. PMEAMeT was
purified 43-fold and has specific activities of 14.7 and 18.0 nmol•min-1•mg-1 protein with
PMEA and PDEA as substrates, respectively. Thin layer chromatography was used to
identify the reaction products formed during the 30 minute assay incubation: with PMEA
as the substrate, PDEA and PCho were detected in a ratio of 9: 1 as products; and with
PDEA as the substrate, PCho was detected as the only product.
PMEAMeT was estimated to have a native molecular mass of 76 kDa by HPLC
gel filtration chromatography. Both PMEA and PDEA N-methylating activities have an
alkaline pH optimum between 8.5 and 9.0 in 0.1 M Tris-HCl buffer. Neither activity was
iii
affected by the omission of Na2-EDT A from the assay. The addition of 10 mM Mg2+ to
the assay inhibited PMEA and PDEA-dependent methylation by approximately 49% and
32%, respectively; whereas, the addition of 1 and 10 mM Mn2+ to the assay completely
inhibited both activities.
Both activities were inhibited by the reaction products S-adenosyl-Lhomocysteine
by over 90% at 0.2 mM and PCho by approximately 80% at 10 mM. Of
the products ofPCho hydrolysis, choline inhibited PMEA-dependent methylation by 10%
at 10 mM; whereas, Pi inhibited PMEA and PDEA-dependent methylation by 38 and
19%, respectively at 10 mM. The compatible osmolyte glycinebetaine inhibited PMEA
and PDEA-dependent methylation by between 20 and 30% at 140 mM; however, the
inibition of PMEA-dependent methylation can be partly accounted for by the presence of
cr ions in the assay. If present at these concentrations in the same subcellular
compartment, these metabolites could serve as regulators ofPMEAMeT activities in vivo.
Study of PMEAMeT contributed to identifying the number of enzymes that Nmethylate
PEA ~ PMEA ~ PDEA ~ PCho and possible regulatory metabolites for
choline biosynthesis in vivo. These data are pertinent to basic research and also to
genetic-engineering studies aimed at introducing the glycinebetaine-accumulating trait
into crop plants as an approach to enhancing osmotic-stress resistance. / Thesis / Master of Science (MSc)
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Choline nutrition and metabolism in sheep / by Brenton Scott RobinsonRobinson, B. S. January 1985 (has links)
Bibliography: leaves 194-219 / xxi, 219 leaves, [2] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1986
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Accumulation of Betaine in the Developing Mouse Oocyte Requires Choline DehydrogenaseMcClatchie, Taylor 05 December 2018 (has links)
In the developing mouse oocyte, as well as in the preimplantation embryo, betaine (N,N,N-trimethylglycine) plays an important role first as a mechanism for cell volume regulation and second as a major methyl donor. Thus, the presence of betaine has implications both during development, and throughout the lifespan. It has previously been observed that betaine accumulates in the mouse oocyte as it matures, however its origin in the egg is unknown.
Here I explore the enzyme choline dehydrogenase (CHDH; EC 1.199.1) as a method by which the mouse oocyte synthesizes the betaine that we observe prior to initiation transport activity in the preimplantation embryo. I carefully monitored betaine transport throughout meiotic maturation to confirm that no other previously unobserved membrane transport existed in the maturing oocyte. However, no betaine transport into oocytes was detected during meiotic maturation suggesting de novo synthesis. Previous data suggests that the enzyme is expressed (at the transcript level) in the developing oocyte, and becomes active during meiotic maturation. I demonstrated the presence of CHDH protein in the oocyte and preimplantation embryo.
I then examined whether the mouse oocyte synthesizes betaine autonomously and addressed whether CHDH is a requirement for this process. Chdh knockout oocytes did not accumulate betaine in vivo, while normal betaine levels were observed in Chdh wildtype oocytes. CHDH-mediated synthesis of betaine was directly confirmed by detection of increased betaine in oocytes matured in vitro in the presence of choline. Chdh-/- oocytes failed to produce betaine when similarly cultured in choline. This establishes the production of betaine as an autonomous process in maturing oocytes. Overall, I have built upon previous data to demonstrate that betaine accumulation is a feature of meiotic maturation that occurs by de novo synthesis of the molecule, a process that requires transient activation of the enzyme choline dehydrogenase.
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Purification and properties of choline acetyltransferase from chicken brainMa, Kelvin January 1978 (has links)
Choline acetyltransferase (ChAc), the enzyme responsible for the synthesis of acetylcholine (ACh), has been extensively purified from chicken brains. Purification procedures included ammonium sulfate fractionation, DEAE-Sephadex (A-25), hydroxyapatite, Sephadex G-150 column chromatography, and affinity chromatography on agarose-hexane-Coenzyme A column. ChAc activity was measured radiochemically. Due to the instability of the enzyme in the course of purification, the most active fraction obtained after agarose-hexane-Coenzyme A chromatography
showed a specific activity of only 0.34 μmoles ACh formed/ min./mg protein which corresponded to a 773 fold purification from homogenate. However, on non-denaturing polyacrylamide gel electrophoresis
at pH 8.8, the highly purified ChAc preparation showed two distinct bands, and ChAc activity was recovered by slicing and assaying the gel. ChAc activity corresponded to the position of the faster moving band. The same preparation showed one major band and two minor bands on SDS gel electrophoresis. The estimated MW of chicken brain ChAc by gel filtration and SDS gel electrophoresis was 42,500 daltons and no subunit was observed. Two forms of chicken brain ChAc with different Km values for the substrates were eluted
from agarose-hexane-CoA column. The pH optimum was estimated to be
between pH 7.6-8.0. NaCl, KC1, Ca²⁺ and EDTA stimulated, while Cu²⁺,
N-ethylmaleimide and CoA inhibited the enzyme preparation. The apparent
Km values for acetyl-CoA and choline were, studied and were found to be similar to those of other mammalian species. The ChAc preparation
also showed species specificity by the Ouchterlony double immuno diffusion test. Effect and mechanisms of salt and EDTA activation of ChAc activity are discussed. / Medicine, Faculty of / Graduate
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