Objective: Nucleolar organiser regions (NORs) are defined as nucleolar components containing a set of argyrophilic proteins, which are selectively stained by silver methods. AgNORs can be identified as black dots localised throughout the nucleolar area by silver method. They accumulate in highly proliferating cells. In this study, we aimed to observe the AgNOR staining in thyroid follicule cells during experimental hypothyroidism.

Material and method: Hypothyroidism was induced in 30 days old male Wistar rats by intraperitoneally injections of propilthiouracil (10 mg/kg day) for 15 day. The thyroid specimens of this rats were stained by AgNOR tecnique and examined in light microscopy.

Results: The results were evaluated statistically by Student t test. Eexperimental groups were compared with their controls about their AgNOR quantitiy.

Conclusion: AgNOR quantity of experimental groups were higher than their control.