The polyamine content of the circulating erythrocyte population in the embryonic chick was studied during its development. Total cellular polyamine content fell dramatically between 5 and 7 days of development, paralleling the decrease in metabolic activity exhibited by these cells. Nuclei were isolated from the erythrocytes by a non-aqueous technique, which not only eliminated the polyamine lo...

N-Methyl-D-aspartate (NMDA) receptors are modulated by extracellular spermine and protons and are blocked in a voltage-dependent manner by spermine and polyamine derivatives such as N1-dansyl-spermine (N1-DnsSpm). The effects of mutations in the first and third transmembrane domains (M1 and M3) and the pore-forming loop (M2) of NMDA receptor subunits were studied. Surprisingly, some mutations i...

The present study was designed to provide a better understanding of the role played by AdoMetDC (S-adenosylmethionine decarboxylase), the key rate-controlling enzyme in the synthesis of spermidine and spermine, in controlling polyamine levels and the importance of polyamines in cardiac physiology. The alphaMHC (alpha-myosin heavy chain) promoter was used to generate transgenic mice with cardiac...

Various ethyl and benzyl spermine analogues, including the anticancer agent N1,N12-bis(ethyl)spermine, were studied for their ability to affect the growth of cultured Escherichia coli cells, to inhibit [3H]putrescine and [3H]spermine uptake into cells, and to modulate the peptidyltransferase activity (EC 2. 3. 2. 12). Relative to other cell lines, growth of E. coli was uniquely insensitive to t...

Biogenic amines (BAs) are low molecular weight nitrogenous organic compounds with different biological activities. Putrescine, spermidine and spermine are essential for the development of the gut and immune system of newborns, and are all found in human milk. Little is known, however, about the role of histamine, tyramine or cadaverine in breast milk. Nor is it known whether mastitis alters the...

PURPOSE To estimate the exchange rates of labile (1) H in citrate and spermine, metabolites present in prostatic secretions, to predict the size of the citrate and spermine CEST effects in vivo. METHODS CEST z-spectra were acquired at high-field [11.7 Tesla (T)] from citrate and spermine solutions at physiological pH (6.5) using saturation power 6 μT. CEST was performed at different temperatu...

Steep rectification in IRK1 (Kir2.1) inward-rectifier K(+) channels reflects strong voltage dependence (valence of approximately 5) of channel block by intracellular cationic blockers such as the polyamine spermine. The observed voltage dependence primarily results from displacement, by spermine, of up to five K(+) ions across the narrow K(+) selectivity filter, along which the transmembrane vo...

Polyamines are required for cell growth and cell division in eukaryotic and prokaryotic organisms. In the unicellular green alga Chlamydomonas reinhardtii, biosynthesis of the commonly occurring polyamines (putrescine, spermidine, and spermine) is dependent on the activity of ornithine decarboxylase (ODC, EC 4.1.1.17) catalyzing the formation of putrescine, which is the precursor of the other t...

A high proportion of piglets fail to adapt to the changing composition of their diet at weaning, resulting in weight loss and increased susceptibility to pathogens. Polyamines are present in sow milk and promote neonatal maturation of the gut. We hypothesised that oral spermine and spermidine supplementation before weaning would increase piglet growth and promote gastrointestinal development at...