Urinary polyamine excretion as related to cell death and cell proliferation induced by carbon tetrachloride intoxication

Tumor markers in serum, polyamines and modified nucleosides in urine, and cytogenetic aberrations in lymphocytes of workers exposed to polycyclic aromatic hydrocarbons

Some polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene and benzo(a)anthracene are well-established genotoxic agents. Long-term exposure to PAHs may lead to proliferative cell disorders in humans, predominantly in the skin, lung, and bladder. The concentration of several tumor markers in serum, of polyamines and modified nucleosides in urine, and of cytogenetic endpoints in peripheral lymphocytes (sister-chromatid exchanges, high frequency cells [HFC], and micronuclei) were measured in 149 male workers exposed to PAHs in two coke oven and one graphite electrode plants, and in 137 controls. We have assessed whether these biomarkers were related to several parameters reflecting exposure to PAHs, i.e., the sum of the airborne concentration of 13 PAHs, 1-hydroxypyrene (1-OHP) concentration in postshift urine, benzo(a)pyrene-diolepoxide adducts to hemoglobin (BPDE-Hb adducts), and duration of exposure, taking also into account several possible confounding factors. HFC was the biomarker most consistently associated with the intensity of current exposure to PAHs. Smoking exerts an independent effect on the same parameter. On the basis of the logistic regression between the prevalence of abnormal HFC values and PAHs in air and 1-OHP in postshift urine found in nonsmokers, it is suggested that the latter should be kept below 6.4 micrograms/m3 and 2.7 micrograms/g creatinine, respectively. No relationship was found between the cytogenetic effects and BPDE-Hb adducts although both parameters are statistically correlated with the airborne PAH level. Some tumor markers in serum (carcinoembryonic antigen, tissue polypeptide antigen, sialic acid) and the urinary concentration of some polyamines were correlated with either PAHs in air or 1-OHP in urine. The associations, however, were very weak which suggests that these biomarkers have limited practical value for the health surveillance of groups of workers exposed to genotoxic PAHs.

Elevation of N1-acetylspermidine and putrescine in hepatic tissues of patients with fulminant hepatitis and liver cirrhosis

Hepatic polyamines were assayed in 15 patients with liver diseases, 5 with fulminant hepatitis (FH); 3 with exacerbated liver cirrhosis (ELC); and 7 with liver cirrhosis (LC). Hepatic putrescine and N1-acetylspermidine as percentages of total polyamines, were elevated and spermine was decreased in all 15 patients. The increase in hepatic N1-acetylspermidine levels appeared to be greater in patients with FH and ELC than in those with LC. These results suggest that the production of N1-acetylspermidine in human liver is closely associated with the induction of spermidine/spermine N1-acetyltransferase activity in liver diseases.

Elevation of acetylpolyamine levels in mouse tissues, serum and urine after treatment with radical-producing drugs and lipopolysaccharide

Polyamines and acetylpolyamines were analyzed in the liver, spleen, lung, kidney, serum and urine by high-performance liquid chromatography on a column of cation-exchange resin after administering various cytotoxic substances to male mice. All of the compounds tested more or less affected the tissue levels of polyamines, including putrescine, spermidine, spermine and acetylpolyamines (N1-acetylspermidine and N1-acetylspermine). It was found that they were classified into two groups of substances: one group (including radical-producing drugs and lipopolysaccharide) which elevated the tissue levels of N1-acetylspermidine, especially in the liver, while another group of drugs (such as D-galactosamine and DL-ethionine) had little effect on the acetylpolyamine levels. When the acetylpolyamine levels rose, the levels of spermidine and spermine declined, and then putrescine levels were elevated. N1-Acetylspermine was detected only when N1-acetylspermidine levels were very high after treatment with radical-producing drugs and lipopolysaccharide. Halogenated carbon, such as carbon tetrachloride and halothane, elevated the levels of acetylpolyamines especially in the liver, while paraquat elevated them in all tissues examined.

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.