title: Effects of spermidine and spermine on DNA synthesis in isolated nuclei and on the activity of DNA polymerases alpha and beta from the mammary gland of pregnant rabbit.
abstract: The rate of [3H]dTMP incorporation by nuclei isolated from the pregnant rabbit mammary gland was affected by polyamines in two distinct ways: a) a general inhibitory effect was evident when spermidine or spermine were added to the incubation mixture at concentrations 10(-3) - 10(-2) M and 10(-4) - 10(-2) M, respectively; and b) a very specific stimulatory effect of either polyamine at a lower concentration which was observed only when the nuclei were incubated in the presence of horse serum. Furthermore, it was demonstrated that 10(-2) M spermine inhibited the activity of the solubilized nuclear DNA polymerases alpha and beta from the mammary gland of pregnant rabbit, separated by sucrose-density-gradient centrifugation and assayed with activated DNA as a template-primer, while spermidine had no effect at any concentration (10(-9) - 10(-2) M tested.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis*; D004256:DNA Polymerase I / Q000378:metabolism; D004257:DNA Polymerase II / Q000378:metabolism; D005260:Female; D008321:Mammary Glands, Animal / Q000201:enzymology*; D011247:Pregnancy; D011270:Pregnancy, Animal; D011817:Rabbits; D013095:Spermidine / Q000494:pharmacology*; D013096:Spermine / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D013096:Spermine; D004247:DNA; D004256:DNA Polymerase I; D004257:DNA Polymerase II; D013095:Spermidine