[Changes in enzyme activity associated with polyamine metabolism in the rat fetal liver during the perinatal period].
Changes in ODC, SAMDC and SAT activity, the rate limiting enzymes in the polyamine metabolism, were measured in the liver of developing rats during the perinatal period. The following results were obtained: ODC activity in fetal rat liver at the 15th day of gestation was 120-fold greater than in mature rat liver, but decreased dramatically as pregnancy advanced. ODC activity during the neonatal period fluctuated at a low level compared with that of the fetus, except for a slight increase at day 5 after birth. SAMDC activity in fetal and mature rat liver was high, but was relatively unchanged throughout the period of development compared with ODC activity. It decreased gradually and increased again toward the mature level from day 5 after birth. SAT activity in fetal rat liver at the 15th day of gestation was significantly high (3-fold that in mature liver) and decreased rapidly with continued fetal development until the 21st day of gestation, when the activity attained that found in mature liver. Thereafter its level was almost constant. There was a positive correlation between ODC activity and growth rate (daily percentage increase) in the weight of liver (r = 0.92, p less than 0.001). There was a similar correlation between SAT activity and growth rate (r = 0.95, p less than 0.001). These results suggest that it is important to raise the putrescine level caused by ODC ornithine----putrescine) and SAT (spermidine----putrescine) with continued fetal development from the viewpoint of polyamine metabolism, which are thought to be involved in cellular proliferation and tissue growth.
D000123:Acetyltransferases / Q000378:metabolism*; D012437:Adenosylmethionine Decarboxylase / Q000378:metabolism*; D000818:Animals; D002262:Carboxy-Lyases / Q000378:metabolism*; D005260:Female; D005333:Fetus / Q000378:metabolism; D008099:Liver / Q000378:metabolism*; D009955:Ornithine Decarboxylase / Q000378:metabolism*; D011073:Polyamines / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D000099228:Diamine N-Acetyltransferase
D000123:Acetyltransferases; D012437:Adenosylmethionine Decarboxylase; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; D011073:Polyamines; D000099228:Diamine N-Acetyltransferase