Lipogenic enzymes in rat maternal adipose tissue in the perinatal period.
1. The specific activities of fatty acid synthetase, acetyl-CoA carboxylase and pyruvate dehydrogenase were measured in rat adipose-tissue extracts in pregnancy and lactation. Fatty acid synthetase specific activity correlates very closely with the rate of fatty acid synthesis, the enzyme specific activity decreasing after mid-pregnancy in a manner very similar to the rate of fatty acid synthesis. Acetyl-CoA carboxylase specific activity also decreases dramatically after mid-pregnancy. Initial pyruvate dehydrogenase specific activity shows a decrease between 2 days pre partum and 2 days post partum, but total enzyme activity shows no significant change in the same period. 2. Immunotitrations of fatty acid synthetase and pyruvate dehydrogenase activities were carried out; the titrations showed that the change in the fatty acid synthetase activity is due to a change in the enzyme amount; the amount of pyruvate dyhydrogenase does not change. Therefore the decrease in fatty acid biosynthesis in subcutaneous and parametrial adipose tissue in late pregnancy and early lactation is associated with a decrease in the amount of at least one of the enzymes involved in fatty acid biosynthesis. The correlation of these events with known hormonal changes is discussed.
D000103:Acetyl-CoA Carboxylase / Q000378:metabolism*; D000273:Adipose Tissue / Q000033:anatomy & histology / Q000201:enzymology*; D000818:Animals; D064429:Fatty Acid Synthases / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis*; D005260:Female; D000882:Haplorhini; D007774:Lactation; D008025:Ligases / Q000378:metabolism*; D009929:Organ Size; D011247:Pregnancy; D011270:Pregnancy, Animal; D011506:Proteins / Q000032:analysis; D011768:Pyruvate Dehydrogenase Complex / Q000378:metabolism*
D005227:Fatty Acids; D011506:Proteins; D011768:Pyruvate Dehydrogenase Complex; D064429:Fatty Acid Synthases; D008025:Ligases; D000103:Acetyl-CoA Carboxylase