On the biogenesis of diamines and polyamines in the pregnant rat.

The urinary excretion of the diamines histamine, methylhistamine, putrescine and cadaverine and the polyamines spermidine and spermine was studied in rats which on the 19th day of pregnancy were subjected to various ectomizing operations. In sham-operated rats the urinary excretion of all the amines studied except spermine was highly elevated on the day preceding the sham-operation and on the 3 days studied post-operatively, i.e. sham-operation did not affect the elevated urinary amine excretion during pregnancy. Foetectomy resulted in an abolished increase in the urinary excretion of histamine and methylhistamine while the excretion of putrescine, cadaverine and spermidine was still significantly increased. Removal of both the foetuses and placentae reduced the excretion of putrescine, cadaverine and spermidine towards the level of non-pregnant rats. Combined hysterectomy and ovariectomy did not cause any additional effects to those after removal of the foetuses and the placentae except for cadaverine, the excretion of which was further reduced.