Food Hunger Lead to DNA Damage of Hippocampal Cells in Rats

Objective To investigate the nuclear DNA damage of hippocampal cells in rats by food hunger. Methods Twenty adult Wistar rats were subjected to food hunger for one week or two months. The single-cell gel electrphoresis (comet assay) was used to evaluate the single-stand breaks (SSBs) of nuclear DNA, and in situ terminal deoxynucleotidyl-transferase-mediated dUTP nick end-labeling (TUNEL) to evaluate the double-stand breaks (DSBs). The immunoreaction of hippocampal cells to the active-caspase-3 segment (P17) antibody was also detected. Hematoxylin and eosin (HE) or Nissl staining was used to learn the changes of the modality and number of hippocampal neurons in the CA1 subregion. Results SSBs were observed in the rats suffering from starvation for 1 week, TUNEL- positive cells were found with special modality. Observation by electron microscopy manifested that neuronal heterochromatin aggregated toward karyotheca. Immunopositive hippocampal cells to active-caspase-3 antibody were not seen at this time-point. For the rats subjected to starvation for two months, SSBs also occurred, but TUNEL-positive cells were disappeared. Interestingly, active-caspase-3 immunopositive cells expressed mostly in cytoplasm instead of in nuclei. HE or Nissl staining suggested a decrease in the number of neurons in CA1 subregion indicative of some neuronal death. Conclusions Food hunger lead to nuclear DNA damage and death of hippocampal cells in rats.