Carte de la partie méridionale de la Grèce moderne : Dressée principalement sur les mémoires de M. Pouqueville, membre de l'Institut, et appuyé sur les observations astronomiques de M. Gauttier / par le Chr. Lapie, ... ; gravée par Flahaut ; écrit par Lallemand

Échelle(s) : [1:1 000 000 environ], 80 km [= 7, 8 cm]

Kansanedustaja Eemil Partanen 11/12 1956

Kirje 11.12.1956

Arlequin journaliste : comédie en un acte, en prose, mêlée de vaudevilles ([Reprod.]) / par les CC. D***, Em. Dupaty et Chazet

Collection : Les archives de la Révolution française ; 12.181

Insulin-like growth factor I (IGF I) stimulates DNA synthesis in fetal rat brain cell cultures.

Addition of insulin, IGF I or IGF II to serum-free cultures of fetal rat brain cells (gestation day 15/16) significantly stimulates DNA synthesis. The dose-response curves show that IGF I is more potent than insulin; half maximal stimulation of [3H]thymidine incorporation is obtained at about 0.4 nM IGF I and 14 nM insulin, respectively. Cultures initiated 2 days later (gestation day 17/18) showed a decreased responsiveness to both peptides. No additive effect was observed after combined addition of both peptides at near-maximal doses. Both peptides show a latency of action of about 12-18 h. In the presence of either IGF or insulin, neuronal as well as glial enzymes are increased, suggesting that neuronal and glial precursor cell division is influenced. IGF I and IGF II interact with a specific binding site for which insulin competes very weakly; however IGF I and IGF II bind with relatively high affinity to the insulin specific binding site. The present results support the hypothesis that both insulin and IGF stimulate mitotic activity by interacting with specific somatomedin receptors and suggest a physiological role of IGF in the developing brain.