Reversible disorder of polyamine and DNA synthesis in regenerating rat liver

: A single injection of diaminohexane (DAH) causes an abrupt but reversible decrease in the putrescine concentration in the regenerating rat liver. Under experimental conditions hepatic spermidine and spermin content remains invariable while the synthesis of these compounds temporarily decreases. Incorporation of the radioactive precursors into proteins and RNA of the regenerating liver does not essentially change after DAH injection. However, DNA synthesis is sharply reduced. Incorporation of 3H-thymidine into DNA directly correlates with the putrescine concentration and spermidine synthesis. The results suggest that putrescine is essential for maintenance of normal DNA replication in the regenerating rat liver.