CORRELATION BETWEEN NUCLEOLAR ORGANIZER REGIONS AND CELL-PROLIFERATION IN PANCREATIC ACINAR CELL PROLIFERATIVE LESIONS IN RATS

The numbers of nucleolar organizer regions (NORs) stained by the one-step silver (Ag) colloid method were measured in rat pancreatic basophilic foci, eosinophilic foci, and acinar cell adenomas induced by 4-hydroxyaminoquinoline 1-oxide (HAQO) followed by crude soybean trypsin inhibitor (SBTI) treatments and compared with values for bromodeoxyuridine (BrdU)-incorporating cells and nuclear DNA contents. Both numbers of AgNORs and BrdU-labeling indices showed stepwise increases from normal pancreatic acinar cells through eosinophilic foci to adenomas, and a good correlation was found between cell proliferation and mean numbers of AgNORs. Microspectrometry of nuclear DNA contents revealed a wide range of values in basophilic and eosinophilic foci and acinar cell adenomas as compared with normal acinar cells, but there was no significant difference in the profile of DNA content among these three proliferative lesions. The present results suggest that mean numbers of AgNORs may reflect cellular kinetics in rat pancreatic acinar cell lesions.