Abstract
A significant inhibition of desoxyribonucleic acid (DNA) synthesis in rat granuloma cells was brought about by 6 repeated administrations (250 mg/kg) of hydroxyurea at 12 hr intervals from day 5 to day 7 after carrageenan injection. The suppressive effect of hydroxyurea on the amount of DNA in granulomatous tissue began to appear on day 8 (12 hr after the last injection of hydroxyurea), and then a maximum inhibition was attained on day 9. The inhibitory effect on the amount of collagen, on the other hand, was disclosed on day 9 with the retardation of around one day to the appearance of suppressive effect on DNA. The cellular activity for collagen synthesis in the hydroxyurea-treated group was gradually elevated accompanying coincidental suppression of DNA synthesis, suggesting that mature cells synthesized collagen more actively than newly formed cells. Suppression of cell proliferation by hydroxyurea seems to result in decrease in the number of mature cells with the retardation of time required for maturation of newly formed cells.
