Sökning: "spermine"
Visar resultat 1 - 5 av 21 avhandlingar innehållade ordet spermine.
1. On the Role of Polyamines in Apoptosis
Sammanfattning : Apoptosis is a kind of death that is best described as cellular suicide and it is important for normal tissue homeostasis. The process can be induced by a number of different stimuli and the dying cell goes through a defined pathway terminating in typical biochemical and morphological alterations of the cell. LÄS MER
2. On the binding of growth-promoting polyamines to proteoglycans: Implications for growth-regulation and polycation-mediated gene transfer
Sammanfattning : Initial investigations were directed at studying the interaction between polyamines and various glycosaminoglycans (GAGs). The polyamine spermine displayed binding to dermatan sulphate (DS) and heparan sulphate (HS) with similar (Kd, 3.9 x 10-4 M) and higher (Kd, 0.37 x 10-6 M) affinity, respectively, than to DNA. LÄS MER
3. Effects of polyamine pool manipulation on genes expressed during the cell cycle
Sammanfattning : The polyamines - putrescine, spermidine and spermine - are polycations found within cells. They have been shown to be essential for optimal cell proliferation and cell survival. Cells maintain their polyamine levels in a well-regulated system involving biosynthesis, catabolism and uptake/excretion. LÄS MER
4. Calcium channel activity and force regulation in smooth muscle: Effects of polyamines and growth stimulation
Sammanfattning : The initial signal for contraction in smooth muscle is an increase in [Ca2+]i. Ca2+ ions can either enter the cytosol from the extracellular medium or be released from intracellular stores. Voltage-operated Ca2+ channels (VOC) play a dominant role in the activation of smooth muscle contraction. LÄS MER
5. Modulation of the calcium-force relationship in smooth muscle by polyamines and metabolic inhibition
Sammanfattning : The relationship between intracellular free calcium ([Ca2+]i) and force in smooth muscle was investigated in receptor-coupled permeabilized preparations and by fluorimetry of the calcium indicator Fura 2 in intact smooth muscle. The time integral of spontaneous [Ca2+]i transients in the intact rat portal vein was decreased by cyanide and, during tonic contraction, cyanide reduced force without changing [Ca2+]i implying metabolic sensitivity of both membrane excitation and [Ca2+]i - activation of the contractile proteins. LÄS MER