Abstract In the day-neutral plant Polianthes tuberosa L.¡]cv. Double¡^putrescine and spermine in corms at the early floral initiation stage decreased by 26 and 35¢M,respectively, compared with those in the vegetative stage. In contrast, a sharp increase in cadeverine and spermidine titres in corms were recorded at the early floral initiation stage. Polyamines in the roots were generally lower than those in the leaves and corms. In no case were the changes in endogenous polyamine titres in the roots and leaves associated with floral initiation and flower development in P. tuberosa. Results indicate that an increase in cadeverine and spermidine titres in the corms seems characteristic of early floral initiation in P. tuberosa. It is also suggested that a significant reduction in putrescine and spermine in the corms is involved in the early floral initiation in P. tuberosa.

No description available.

No description available.

No description available.

Methylglyoxal bis(guanylhydrazone) (MGBG) was incorporated extensively into baby hamster kidney (BHK-21/C13) cells by a temperature - and Na⁺, K⁺ - ATPase linked mechanism. The uptake of the drug was dependent on the growth state of the cells and transformed cells (PyY-cells) incorporated MGBG to a greater extent than normal BHK cells. The uptake of the drug was inhibited by coadministration with spermidine, spermine and N¹-acetylspermine and to a lesser extent by putrescine and Mg²⁺ ions. MGBG and spermine were cytotoxic and both compounds stimulated spermidine acetyltransferase (SAT) activity in BHK cells but not in PyY-cells suggesting that transformation enhanced resistance of the cells.SAT activity was present in both the nuclear and cytosolic compartment of both cell-lines and MGBG stimulation resulted in an increase in both N¹- and N⁸-acetylspermidine production in the nucleus and almost exclusive N¹-acetylspermidine production in the cytosol. MGBG stimulated spermine acetyltransferase activity in both nuclear and cytosolic compartments of mammalian cells. Increased intracellular acetylation after MGBG-treatment resulted in enhanced excretion of putrescine and N¹-acetylspermidine from both BHK- and PyY-cells implicating acetylation as a means to control intracellular polyamine content. MGBG was itself acetylated in the nucleus of both cell-lines, as was putrescine. However, prior MGBG treatment inhibited the acetylation of MGBG itself and the diamine suggesting that the two compounds are acetylated by a common nuclear acetyltransferase.A cytosolic spermidine acetyltransferase enzyme was purified over 2000-fold from BHK-cells and was found to acetylate putrescine, spermidine, spermine and MGBG. The activity of the enzyme preparation to all these compounds suggests that the enzyme preparation contained nuclear acetyltransferase activity. A model is preposed for the role of acetylation in both the nuclear and cytosolic compartments of mammalian cells.

This project was aimed at synthesising, characterising and examining the properties of the novel polyamine ligand 4’-{2’”-(12-Amino-2,6,9-triazadodecyl)-phenyl}-2,2’:6’,2”-terpyridine and its related complexes. The ligand would be based around the 4’-(o-toluyl)-2,2’:6’,2”-terpyridine framework and have potential applications in analytical chemistry. The 4’-(o-toluyl)-2,2’:6’,2”-terpyridine framework would have a tail attached on the functionalised o-toluyl methyl group. The ortho toluyl functionality was chosen so that the donor atom containing tail would be directed back towards the coordination site. This would make it easier for the tail to interact with a central metal ion. There is potential to be able to change the number and type of donor atom in the tail so that the ligand may be metal ion selective. As the tail would contain donor atoms, the denticity of the ligand would be increased making it more applicable for complexometric titrations. The 2,2’:6’,2” terpyridines exhibit strong colours when coordinated to selective metal ions and so would have potential applications in colorimetry also. The ligand was successfully synthesised and characterised. In a multi-step process, the 4’-(o-toluyl)-2,2’:6’,2”-terpyridine underwent radical bromination before the tail was attached. The tail used in this research was N,N'-bis (3-aminopropyl)ethane-1,2-diamine (3,2,3-tet). The secondary amines in this polyamine tail were protected before addition to the brominated 4’-(o-toluyl)-2,2’:6’,2”-terpyridine to ensure terminal addition. After the tail addition, a two step separation process purified a sample of 4’-{2’”-(12-Amino-2,6,9-triazadodecyl)-phenyl}-2,2’:6’,2”-terpyridine for analysis. Due to the late stage in this research where a successful separation technique was found, little work was done on examining the properties of this ligand and its complexes.

No description available.

The objective of this study was to determine concentrations of amino acids and polyamines as well as nitric oxide (NO) and polyamine synthesis in the ovine conceptus (embryo/fetal and associated placental membrane). Ewes were hysterectomized on Days 30, 40, 60, 80, 100, 120, or 140 of gestation to obtain allantoic and amniotic fluids, intercotyledonary placenta, placentomes and uterine endometrium for the analyses. Alanine, citrulline plus glutamine accounted for about 80% of total α-amino acids in allantoic fluid during early gestation. Serine (16.5 mM) contributed about 60% of total α-amino acids in allantoic fluid on Day 140 of gestation. Maximal ornithine decarboxylase (ODC) and arginase activities and highest rates of polyamine and NO synthesis occured in all tissues on Day 40 of gestation. In ovine allantoic and amniotic fluids, polyamines were most abundant during early (Days 40-60) and late (Days 100-140) gestation, respectively. Activity of guanosine 5??-triphosphate-cyclohydrolase I (GTP-CH), and concentrations of NOS cofactors, tetrahydrobiopterin (BH4) and NADPH (nicotinamide adenine dinucleotide), peaked on Day 40 of gestation in placental and endometrial tissues. In these tissues, NO synthesis was positively correlated with total NOS activity, GTP-CH activity, and concentrations of BH4 and NADPH. The physiological significance of these changes was manifested by undernutrition-induced intrauterine growth retardation (IUGR). Maternal undernutrition (50% of National Research Council nutrient requirements) reduced concentrations of total α-amino acids in fetal plasma and fluids, and retarded fetal growth at both mid (Day 78) and late (Day 135) gestation. Concentrations of polyamines in fetal fluids were lower in underfed ewes than in control-fed ewes. Realimentation of underfed ewes between Days 78 and 135 of gestation increased concentrations of total α-amino acids and polyamines in fetal plasma and fluids, when compared with non-realimented ewes. Results of these studies demonstrate metabolic coordination among the several integrated pathways to enable high rates of polyamine and NO synthesis in the placenta and endometrium during early pregnancy. Collectively, our findings may have important implications for both IUGR and fetal origins of adult disease.

The objective of this study was to determine concentrations of amino acids and polyamines as well as nitric oxide (NO) and polyamine synthesis in the ovine conceptus (embryo/fetal and associated placental membrane). Ewes were hysterectomized on Days 30, 40, 60, 80, 100, 120, or 140 of gestation to obtain allantoic and amniotic fluids, intercotyledonary placenta, placentomes and uterine endometrium for the analyses. Alanine, citrulline plus glutamine accounted for about 80% of total α-amino acids in allantoic fluid during early gestation. Serine (16.5 mM) contributed about 60% of total α-amino acids in allantoic fluid on Day 140 of gestation. Maximal ornithine decarboxylase (ODC) and arginase activities and highest rates of polyamine and NO synthesis occured in all tissues on Day 40 of gestation. In ovine allantoic and amniotic fluids, polyamines were most abundant during early (Days 40-60) and late (Days 100-140) gestation, respectively. Activity of guanosine 5??-triphosphate-cyclohydrolase I (GTP-CH), and concentrations of NOS cofactors, tetrahydrobiopterin (BH4) and NADPH (nicotinamide adenine dinucleotide), peaked on Day 40 of gestation in placental and endometrial tissues. In these tissues, NO synthesis was positively correlated with total NOS activity, GTP-CH activity, and concentrations of BH4 and NADPH. The physiological significance of these changes was manifested by undernutrition-induced intrauterine growth retardation (IUGR). Maternal undernutrition (50% of National Research Council nutrient requirements) reduced concentrations of total α-amino acids in fetal plasma and fluids, and retarded fetal growth at both mid (Day 78) and late (Day 135) gestation. Concentrations of polyamines in fetal fluids were lower in underfed ewes than in control-fed ewes. Realimentation of underfed ewes between Days 78 and 135 of gestation increased concentrations of total α-amino acids and polyamines in fetal plasma and fluids, when compared with non-realimented ewes. Results of these studies demonstrate metabolic coordination among the several integrated pathways to enable high rates of polyamine and NO synthesis in the placenta and endometrium during early pregnancy. Collectively, our findings may have important implications for both IUGR and fetal origins of adult disease.

This project was aimed at synthesising, characterising and examining the properties of the novel polyamine ligand 4’-{2’”-(12-Amino-2,6,9-triazadodecyl)-phenyl}-2,2’:6’,2”-terpyridine and its related complexes. The ligand would be based around the 4’-(o-toluyl)-2,2’:6’,2”-terpyridine framework and have potential applications in analytical chemistry. The 4’-(o-toluyl)-2,2’:6’,2”-terpyridine framework would have a tail attached on the functionalised o-toluyl methyl group. The ortho toluyl functionality was chosen so that the donor atom containing tail would be directed back towards the coordination site. This would make it easier for the tail to interact with a central metal ion. There is potential to be able to change the number and type of donor atom in the tail so that the ligand may be metal ion selective. As the tail would contain donor atoms, the denticity of the ligand would be increased making it more applicable for complexometric titrations. The 2,2’:6’,2” terpyridines exhibit strong colours when coordinated to selective metal ions and so would have potential applications in colorimetry also. The ligand was successfully synthesised and characterised. In a multi-step process, the 4’-(o-toluyl)-2,2’:6’,2”-terpyridine underwent radical bromination before the tail was attached. The tail used in this research was N,N'-bis (3-aminopropyl)ethane-1,2-diamine (3,2,3-tet). The secondary amines in this polyamine tail were protected before addition to the brominated 4’-(o-toluyl)-2,2’:6’,2”-terpyridine to ensure terminal addition. After the tail addition, a two step separation process purified a sample of 4’-{2’”-(12-Amino-2,6,9-triazadodecyl)-phenyl}-2,2’:6’,2”-terpyridine for analysis. Due to the late stage in this research where a successful separation technique was found, little work was done on examining the properties of this ligand and its complexes.