RESUMO
The proliferative activity of gastric mucous cells (GMC) was studied in white mice following the administration of acetylsalicylic acid (200 mg/kg). One hour before sacrifice all the animals received intraperitoneal injection of 3H-thymidine. The mitotic index and index of labeling nuclei were calculated by means of radioautographers 3, 10 and 20 days after administering the drug. Following 3-day exposure to acetylsalicylic acid the proliferative activity of GMC remained unchanged as compared to controls. Long-term administration (10 and 20 days) of the drug produced no increase in the number of erosions, but there was a statistically significant rise in the proliferative activity of GMC. This rise was accounted for by increased number of proliferating cells in the foveated and cervical divisions of the glands as well as due to the extension of the zone of distribution of precursor cells in the gastric glands as far as the basal divisions. These changes may be considered as manifestation of the protective-adaptive reaction of the gastric mucosa in response to the damaging effect of acetylsalicylic acid.
