title: Stimulation of ornithine decarboxylase activity by insulin in developing rat brain.
abstract: Insulin administered ip or intracisternally (ic) increased the activity of ornithine decarboxylase (ODC) in whole brains and brain parts of neonatal rats. Maximal stimulation of activity occurred 4-5 h after ip administration. At the highest doses, insulin stimulated ODC activity by up to 5- and 8-fold after ip and ic injection, respectively. The same amount of insulin given ic caused greater increases in activity than when given ip. Insulin stimulated ODC activity in 2-day-old and in 17- to 60-day-old rats but not in 5- or 9-day old neonates or 80-day-old adults. When insulin-induced hypoglycemia was prevented by giving dextrose, the stimulation of ODC activity was approximately the same as that in animals receiving insulin without dextrose. This indicates that insulin-induced stimulation of brain ODC activity was not caused by insulin-induced hypoglycemia or physiological responses to hypoglycemia. Since ODC is considered an indicator of growth stimulation, these results suggest that insulin or insulin-like peptides have a role in the regulation of brain development.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose / Q000032:analysis; D001921:Brain / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D002262:Carboxy-Lyases / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005260:Female; D005333:Fetus; D006854:Hydrocortisone / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology*; D007700:Kinetics; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats
chemical_list: D001786:Blood Glucose; D007328:Insulin; D000324:Adrenocorticotropic Hormone; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D006854:Hydrocortisone