title: Stimulation of ornithine decarboxylase activity by luteinizing hormone in rat testicular interstitial cells in vitro is age dependent.
abstract: The developmental pattern of ornithine decarboxylase (ODC) responsiveness to luteinizing hormone (LH) in isolated rat testicular interstitial cells in vitro was examined and correlated with testosterone production by the same cells. LH caused a 60-100% stimulation of ODC activity in cells from 60-day-old rats but produced no response in cells from 30, 37, 41, 50 and 55-day-old animals. Interstitial cells from 25-day-old rats responded with a moderate (40%) but statistically significant enhancement of ODC activity to the highest LH dose (100.0 ng/ml) only. Testosterone production by control cells was low until day 41 (0.15-0.30 ng/10(6) cells per 4 h), and then markedly increased to adult levels (2.12 +/- 0.03 10(6) cells per 4 h). LH in all concentrations (0.1 - 100.0 ng/ml) employed caused a consistent 4 to 7-fold stimulation of testosterone production in interstitial cells at all ages studied. This study shows age-dependent stimulation by LH of ODC activity in rat testicular interstitial cells in vitro and no apparent correlation with testosterone production by the same cells.
mesh_terms: D000375:Aging; D000818:Animals; D002262:Carboxy-Lyases / Q000378:metabolism*; D007985:Leydig Cells / Q000187:drug effects / Q000201:enzymology*; D007986:Luteinizing Hormone / Q000494:pharmacology*; D008297:Male; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013739:Testosterone / Q000378:metabolism
chemical_list: D013739:Testosterone; D007986:Luteinizing Hormone; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase