EFFECT OF CHEMICAL CARCINOGENS ON PANCREATIC DNA-SYNTHESIS INVIVO

  • 1 January 1976
    • journal article
    • research article
    • Vol. 67  (6) , 781-786
Abstract
The effect of dimethylnitrosamine (DMN), ethionine, streptozotocin, N-methyl-N-nitrosourethan (MNUT), N-bis(2-hydroxypropyl)nitrosamine (DHPN), azaserine and 4-hydroxyaminoquinoline-1-oxide (4-HAQO) on DNA synthesis after partial pancreatectomy was studied. DNA synthesis of the residual pancreas occurred and reached the maximum value at 3 days and returned to the control value 12 days after surgery. DNA synthesis, which was inhibited 96.7% by hydroxyurea 3 days after surgery, indicated that semiconservative DNA synthesis occurred in the residual pancreas. DMN and ethionine, nonpancreatic carcinogens, did not inhibit while DHPN, MNUT, azaserine and 4-HAQO, pancreatic nonendocrine carcinogens, inhibited DNA synthesis in the rat pancreas by 57.9, 76.4, 71.7 and 82.1%, respectively. The effect of streptozotocin, a pancreatic endocrine carcinogen, on DNA synthesis was not clear from the present experiments. Further effects on the inhibition of DNA synthesis by these carcinogens was obtained by dose-response studies and the results indicated a correlation existed between pancreatic carcinogens and the inhibition of DNA synthesis after partial pancreatectomy in rats.