Metabolism of putrescine in the pregnant rat

Ornithine decarboxylase, transglutaminase, diamine oxidase and total diamines and polyamines in maternal liver and kidney throughout rat pregnancy

Ornithine decarboxylase (ODC; EC 4.1.1.17), transglutaminase (EC 2.3.2.13), diamine oxidase (DAO; EC 1.4.3.6) and total di- and poly-amines were studied in rat liver and kidney cortex throughout pregnancy. In liver, ODC activity exhibited two major peaks (4.5-5 times the control activities) on days 15 and 17. Also putrescine and spermidine increased biphasically (3-4-fold), but no variation in spermine content was observed. Transglutaminase activity showed slight variations only near the end of gestation. In kidney, ODC activity did not fluctuate significantly during pregnancy, whereas both transglutaminase activity and putrescine content showed three major increases, in very early, middle and late pregnancy. No significant variations in spermidine and spermine were observed. In both organs, DAO activity, very low or undetectable until day 10, dramatically increased (10- and 20-fold in kidney and liver respectively) in the second half of pregnancy, reaching maxima on days 16-17 and 19. The results obtained for transglutaminase, ODC and total di- and poly-amines are interpreted on the basis of hyperplastic and hypertrophic events in the liver and kidney respectively. The behaviour of DAO suggests that the enzyme plays an important role in the control of intracellular diamine concentration.

In vitro metabolism of cadaverine in the pregnant rat

The in vitro metabolism of 14C-cadaverine by diamine oxidase was investigated in various tissues of pregnant and non-pregnant rats. The metabolites formed were: delta 1-piperideine, delta-aminovaleric acid, carbon dioxide and some unidentified compound(s). In most of the tissues investigated delta 1-piperideine was the predominant metabolite, but considerable amounts of delta-aminovaleric acid and the unidentified compound(s) were also formed. The oxidative products of cadaverine might be of importance in various physiological and pathophysiological connections associated with elevated diamine oxidase levels.