The biosynthesis of N-putrescinylthymine (NpT), a modified pyrimi-dine which occurs in the DNA of phage φW-14, was studied. Prior to this study, the metabolism of arginine and polyamines in the host organism, Pseudomonas acidovorans 29, was investigated. P. acidovorans transported ornithine and arginine but not putrescine. Neither amino acid was used as a sole source of nitrogen. Thus arginine cannot be catabolized to putrescine and ornithine is not catabolized to γ-aminobutyrate. Ornithine was synthesized from glutamate but the operation of this pathway was not inhibited by high concentrations of arginine. Since ornithine was decarboxylated to putrescine, this single route for the synthesis of polyamines is unusual in that ornithine biosynthesis is constitutive. P. acidovorans and φW-14 contain an unusual complement of polyamines: spermidine, putrescine and 2-hydroxyputrescine. Their respective bacterial concentrations (mM) were: 3-5, 50 and 45, phage infection led to an increase in the proportion of putrescine. ¹⁴C-Ornithine was used to label NpT in phage DNA. ¹⁴C-5-Ornithine exclusively labelled NpT, whereas ¹⁴C-1-ornithine was totally ineffective in this capacity. Hence, the carboxyl group of ornithine is not a constituent of the NpT molecule. Labelling of NpT with ¹⁴C-3-serine demonstrated a tetrahydrofolate (THF) involvement in its biosynthesis. The use of ³H-2,3-serine showed that N¹⁰methylene THF was the carbon donor for the pyrimidine precursor of NpT. It is proposed that NpT is synthesized in the following way: 5-hydroxymethyl deoxyuridine monophosphate is formed by the interaction of N¹⁰ methylene THF and deoxyuridine monophosphate; putrescine then condenses with the hydroxymethyl group of the nucleotide to yield N-putrescinyl-thymine. / Science, Faculty of / Microbiology and Immunology, Department of / Graduate

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Putrescine is a polyamine with multiple roles in cellular metabolism. It is also a minor precursor of the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). Conversion of systemically administered putrescine to GABA in rat neural tissues has been reported. In this thesis, three experiments were conducted to characterize changes in rat behavior after putrescine administration, and determine if any effects resembled known GABAergic behaviors. Experiments l and 2 investigated the behavioral consequences of oral and intraperitoneal putrescine treatment. Male adult rats were given either saline or putrescine doses and tested with seven procedures which evaluated motor behavior, sensory reactivity, body temperature, and other behaviors. Results showed that putrescine-treated subjects exhibited significant changes in behavior compared to saline controls, and that certain effects resembled behaviors related to the function of GABA and/or other neurochemicals. Experiment 3 investigated the modifying effects of putrescine treatment on behavior induced by a dopamine agonist, apomorphine, and were compared to effects produced by a GABA agonist, muscimol. Male adult rats were given either saline, putrescine, or muscimol, and later treated with saline or apomorphine. Locomotor and specific activities were time sampled for 45 minutes. Results indicated that putrescine and muscimol had similar interactions with apomorphine in modifying sniffing stereotypies. From the behavioral evidence obtained in this thesis, it was suggested that systemic putrescine administration may indirectly influence behavior in the rat via GABAergic mechanisms. The results were interpreted as preliminary support for a significant neuropharamacological role of putrescine in the mammalian central nervous system. / Master of Science

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Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1994. / Vita. Abstract. Includes bibliographical references (leaves 61-73). Also available via the Internet.

Orientador: Ana Silvia Alves Meira Tavares Moura / Resumo: O objetivo do presente trabalho foi avaliar o efeito da adição de óleo de linhaça (OL) ou farelo de linhaça (FL) na dieta de ovelhas da raça Bergamácia em lactação, sobre o teor de aminas biogênicas e polifenóis no leite. Foram utilizadas 70 ovelhas distribuídas aleatoriamente entre os tratamentos. As dietas experimentais foram: Controle (CT) – concentrado sem adição de suplementação lipídica; Óleo de linhaça (OL) – concentrado com adição de 3% de OL (%MS); e Farelo de linhaça (FL) – concentrado com adição de 15% de FL (%MS). Durante todo o período experimental, os animais foram mantidos confinados em baias coletivas e recebiam dieta composta por 60% de silagem de milho e 40% de concentrado referente a cada tratamento. As ovelhas foram ordenhadas uma vez ao dia, no período da manhã, e tiveram suas produções controladas diariamente. As amostras de leite para a avaliação das aminas biogênicas foram colhidas a cada 14 dias a partir do primeiro dia de ordenha e as amostras de leite para análise dos polifenóis foram colhidas a cada 14 dias a partir do quinto dia pós-parto. O experimento foi conduzido no delineamento inteiramente casualizado e os dados avaliados por análise de variância (P< 0,05). Não foi encontrada a presença de cadaverina no leite e a serotonina foi a amina predominante no leite de ovelhas em todos os tratamentos. O tratamento controle apresentou maiores teores de espermina (0,300 mg/100g) entretanto, o tratamento com óleo de linhaça apresentou menores teores de ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim in this study was to determine the effects of feeding diets with linseed oil (OL) or flaxseed meal (FM) of Bergamasca ewes on to the content of biogenic amines and phenols in milk.Seventy ewes were distributed in three groups: Control (CT) - no lipids; Linseed (L) – with addition of 3% of OL (DM basis); and Flaxseed meal (F) – with addition of 15% of FM (DM basis). Throughout the experiment, the ewes remained confined in collective pens and were fed a diet containing 60% corn silage and 40% concentrate according to each treatment. They were mechanically milked once a day and had their productions controlled. The milk samples for biogenic amines analysis were collected every 14 days from the first milking day and the milk samples for phenols analysis were collected every 14 days from the 5th day postpartum until de end of the lactation. The experiment was conducted in a random customized design and the data evaluated by analysis of variance (P< 0,05). Cadaverine was not found and the serotonine was the predominant amine in the milk from ewes in all treatments. The control treatment showed high contents of espermine (0,300 mg/100g), however the OL had lower contents of histamine (0,0049 mg/100g). The espermidine was the biogenic amine more correlated with greater numbers of amines. There was no difference between treatments for polyphenols contents in milk, however the treatment with oil it was more efficient. / Doutor

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13344号 / 論農博第2887号 / 新制||農||1079(附属図書館) / 学位論文||R2||N5251(農学部図書室) / (主査)教授 小川 順, 教授 木岡 紀幸, 教授 栗原 達夫 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

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