title: A possible novel mechanism underlying temperature-dependent uptake of [3H]spermidine in nuclear fractions of murine brain.
abstract: [3H]Spermidine (SPD) was accumulated in subcellular fractions enriched of the nucleus in a temperature-dependent manner with a saturable profile in murine brain. The accumulation reached a plateau within 30 min at 2 degrees C and 30 degrees C, while excess unlabeled SPD significantly inhibited the accumulation at 2 degrees C without markedly affecting that at 30 degrees C when added after equilibrium. The temperature-dependent accumulation of [3H]SPD was significantly inhibited by the triamine SPD and the tetraamine spermine, but not by the diamine putrescine. Phospholipases were invariably effective in significantly inhibiting the accumulation at 30 degrees C in a concentration-dependent manner. Amongst different discrete murine central structures examined, the temperature-dependent [3H]SPD accumulation was highest in neocortex with progressively lower activities in striatum, hypothalamus, spinal cord, medulla-pons, hippocampus, midbrain and cerebellum. These results suggest the possible presence of a hitherto unidentified nuclear transport system for particular polyamines in murine brain.
authors.affiliation: Laboratory of Molecular Pharmacology, Kanazawa University Graduate School of Natural Science and Technology, 13-1 Takara-machi, Kanazawa, Ishikawa 920-0934, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kuramoto
authors.forename: Keiji
authors.initials: K
authors.lastname: Inoue
authors.forename: Katsura
authors.initials: K
authors.lastname: Takano
authors.forename: Hideo
authors.initials: H
authors.lastname: Taniura
authors.forename: Katsumi
authors.initials: K
authors.lastname: Sakata
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Ogita
authors.forename: Yukio
authors.initials: Y
authors.lastname: Yoneda
mesh_terms: D000255:Adenosine Triphosphate; D000818:Animals; D001692:Biological Transport; D001831:Body Temperature / Q000502:physiology*; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000494:pharmacology; D006160:Guanosine Triphosphate; D006657:Histones / Q000378:metabolism; D015151:Immunoblotting; D007700:Kinetics; D008297:Male; D051379:Mice; D015530:Nuclear Matrix / Q000378:metabolism*; D010740:Phospholipases / Q000494:pharmacology; D011073:Polyamines / Q000493:pharmacokinetics; D011419:Propidium / Q000493:pharmacokinetics; D012710:Serum Albumin, Bovine / Q000494:pharmacology; D013095:Spermidine / Q000493:pharmacokinetics*; D013347:Subcellular Fractions / Q000378:metabolism; D013997:Time Factors; D014316:Tritium / Q000493:pharmacokinetics; D014909:Wheat Germ Agglutinins / Q000494:pharmacology
chemical_list: D006657:Histones; D011073:Polyamines; D014909:Wheat Germ Agglutinins; C061171:wheat germ agglutinin-bovine serum albumin; D014316:Tritium; D012710:Serum Albumin, Bovine; D011419:Propidium; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D010740:Phospholipases; D006026:Glycoside Hydrolases; D013095:Spermidine