Escherichia coli B infected by the DD mutant of T4, am N116, is stimulated to initiate deoxyribonucleic acid accumulation by 1 to 10 mm spermidine but not by 10 mm putrescine. The syntheses of putrescine and spermidine in cells infected by T4D and the mutant are similar, although slight differences are observed in the intracellular concentration of free spermidine. Unlike r-K12 (lambda) systems...

BACKGROUND Rapidly regenerating tissues need sufficient polyamine synthesis. Since the hair follicle (HF) is a highly proliferative mini-organ, polyamines may also be important for normal hair growth. However, the role of polyamines in human HF biology and their effect on HF epithelial stem cells in situ remains largely unknown. METHODS AND FINDINGS We have studied the effects of the prototyp...

Dietary spermidine is emerging as a substance with promising health-promoting and healthy ageing-promoting properties. Its autophagy-inducing potential has been especially well-documented. This process suspected to be at the root of life-prolonging effects fasting in-vivo supplementation. In humans, high dietary intake associated lifespan increase 5.7 years. Numerous studies provide indications...

In order to investigate the effect of priming on aspects germination aged pumpkin seeds under drought stress, a factorial experiment was conducted based completely randomized design with four replications in laboratory. Treatments included aging (control, 85% and 75% control germination), stress (0, -0.75 -1.5 MPa), hydro, gibberellin, GR24, benzyl aminopurine spermidine). Results mean comparis...

Background Spermidine has been shown both in vitro and in mice models to have an anagen-prolonging effect on hair follicles (HFs). Objectives To evaluate the effects of a spermidine-based nutritional supplement on the anagen phase of HFs in healthy human subjects in a randomized, double-blind, placebo-controlled trial. Methods One hundred healthy males and females were randomized to receive...

Diamine oxidase was previously measured in human pregnancy serum with putrescine or histamine as substrate. We have now documented the presence of spermidine oxidase activity in pregnancy serum by means of a specific radioactive assay with l '4Clspermidine as substrate and Dowex 50 cation-exchange chromatography to separate products from substrate. The apparent Km of a partially purified prepar...

A series of diamine homologues of putrescine and triamine homologues of spermidine was used to determine the structural specificity of the polyamine transport system in asertes L1210 leukemia cells by measuring their ability to compete with [3H]putrescine, [3H]spermidine, or [3H]spermine for uptake. Trans port specificity among the diamines (as indicated by K,constants) was greatest for those h...

In most organisms, S-adenosyl-L-methionine decarboxylase (SAMDC EC 4.1 .I SO) plays a pivotal role in polyamine biogenesis by contributing S-methyladenosylhomocysteamine which in turn donates its propylamine moiety in a stepwise manner to putrescine and spermidine to yield spermidine and spermine, respectively [l-3]. Two distinct and separable enzymes, namely spermidine synthase (EC 2.5 .l .I 6...

Putrescine, NHz(CH&NHZ, spermidine, NHz(CH&NH(CH&NHt, and sperminc, NH2(CH&NH(CH&NH(CH&NHt, are naturally occurring polyamines (for bibliography see ref. 6). That they have physiological significance is suggested by the following: they have been shown to be essential growth factors for Hemophilus injluenza (7-9) and for a mutant of Aspergillus nidulam (lo), and to stimulate the growth of Lactob...

UNLABELLED Polyamines are found in all groups of cyanobacteria, but their role in environmental adaptation has been barely investigated. In Synechocystis sp. strain PCC 6803, inactivation of spermidine synthesis genes significantly reduced the survivability under chill (5°C)-light stress, and the survivability could be restored by addition of spermidine. To analyze the effects of spermidine on ...