Expression of PCNA and Ki-67 in the rat submandibular gland after one year cadmium intoxication--a preliminary study.

The aim of our study was to determine to what degree one-year exposure of female rats to cadmium at a dose of 5, 50 and 100 mg Cd/l affects cell proliferation in the submandibular gland, shown by PCNA and Ki-67 expression. In the present study, we found a positive nuclear reaction for PCNA in single cells in microscopic preparations of control rats. In Group I, an increase was observed in the number of PCNA-positive cells, compared to that in the control. In Group II, the number of PCNA-positive cells was markedly higher than that in Group I and in the control. In the submandibular glands of rats in Group III, the number of PCNA-positive cells was similar to that, found in Group II. However, Ki-67 expression was sporadically observed in control submandibular glands, but not in Groups I, II and III.