Investigation of argyrophilic nucleolar organizing region.

BACKGROUND

Ischemia/reperfusion (I/R) injury is a complex event frequently observed in vascular surgery and can cause functional and structural cell damage. Nucleolar-organizing regions (NORs) are sites of the ribosomal genes located on chromosomes and can be stained with silver when they are active. Thus these proteins are named as argyrophilic-NOR (AgNOR)-associated proteins. We aimed to investigate any possible effects of renal I/R injury on the NOR protein synthesis and association between the AgNOR proteins amount and histopathological injuring score.

METHODS

Nine female wistar-albino rats with weight of 200-250g were included into the study. The animals were randomly divided in two groups, a Control Group and an I/R Group. In I/R group, rats were subjected to 45 minutes of renal pedicle occlusion followed by 24 hours of reperfusion. In the control group no drug injections or ischemia reperfusion were performed in animals. Then histopathological injury score, mean AgNOR number and total AgNOR area/nuclear area (TAA/NA) were detected for each rat.

RESULTS

The differences between control and I/R groups were significant for histopathological injury scores (p = 0.016). Also the differences between control group and I/R group were significant for mean AgNOR number (p = 0.000) and TAA/NA ratio (p = 0.000). Additionally, there was a positive correlation between TAA/NA ratio and histopathological injury score (r = 0.728; p = 0.026) and between mean AgNOR number and histopathological injury score (r = 0.670; p = 0.048).

CONCLUSION

The detection of AgNOR proteins amount may be used as an indicator to obtain information about the cellular behaviour (self-protective mechanism of tubular epithelial cells) against I/R injury and cellular damage levels (Tab. 2, Fig. 4, Ref. 24).