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...

This paper reviews the relationships between the effects of glucocorticoids on rat pancreatic acinar AR42J cell polyamine levels and cellular growth and differentiation. Glucocorticoids inhibit the growth of AR42J cells. Glucocorticoids either stimulate or inhibit the formation of polyamines in a variety of cell types. Cells require polyamines for normal growth. Therefore, we tested the hypothe...

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 ascites L1210 leukemia cells by measuring their ability to compete with [3H]-putrescine, [3H]spermidine, or [3H]spermine for uptake. Transport specificity among the diamines (as indicated by K1 constants) was greatest for those ...

Polyamines are ubiquitous biologically active aliphatic cations that are at least transiently available in the soil from decaying organic matter. Our objectives in this study were to characterize polyamine uptake kinetics in Phytophthora sojae zoospores and to quantify endogenous polyamines in hyphae, zoospores, and soybean roots. Zoospores contained 10 times more free putrescine than spermidin...

Polyamines regulate a variety of cation and K(+) channels, but their potential effects on cation-transporting ATPases are underexplored. In this work, noninvasive microelectrode ion flux estimation and conventional microelectrode techniques were applied to study the effects of polyamines on Ca(2+) and H(+) transport and membrane potential in pea roots. Externally applied spermine or putrescine ...

Polyamines relax several smooth muscles and elicit cardiotonic effects in the rat heart via interactions with β-adrenoceptors. The aim of this work was to establish whether β(2)-adrenoceptors were involved in polyamine-relaxation of bovine tracheal strips. Endogenous polyamines displaced the specific radioligand, [(3)H]dihydroalprenolol, but spermine was the most potent. The polyamines elicited...

Putrescine and spermidine were the dominant polyamines in Tetrahymena cells. Spermine was present only in very small amounts. Changes in the amount of putrescine during and after the synchronizing heat treatment followed a definite quantitative pattern. Changes in the amount of spermidine were similar, though not so pronounced. The changes may be due to a varied influx of polyamines into the ce...