Increased urinary polyamine excretion during liver regeneration.
Tumor growth is a process associated with both cell proliferation and cell death. The increase in polyamine excretion observed in cancer patients may be partly due to leakage of polyamines from proliferating cells, which all contain an elevated polyamine level. However, the increased polyamine excretion may also be due to a release of polyamines from dead or damaged cells. To determine if actively proliferating cells release polyamines, the urinary polyamine excretion was measured during a proliferative event associated with minimal cell necrosis. Rats subjected to partial hepatectomy were used as an experimental model. Their 24-hr urines were collected during 6 consecutive days following the operation. Rat liver regeneration is characterized by a proliferation wave with a maximum 24 hr after the operation. The 24-hr urinary putrescine excretion reached a maximum 2 days after the operation and then decreased. The 24-hr urinary spermidine excretion increased during the second day following operation and remained essentially unchanged during the rest of the experimental period. Although there is an apparent correlation between elevated urinary polyamine excretion and the proliferative activity, concurrent permeability changes and necrotic events may contribute to the increase in polyamine excretion.
D000818:Animals; D004261:DNA Replication; D008099:Liver / Q000378:metabolism; D008115:Liver Regeneration; D008297:Male; D011700:Putrescine / Q000652:urine*; D051381:Rats; D011919:Rats, Inbred Strains; D013095:Spermidine / Q000652:urine*; D013997:Time Factors
D013095:Spermidine; D011700:Putrescine