Abstract
Polaprezinc, an anti-gastric ulcer drug, is a chelate compound consisting of zinc and L-carnosine. Polaprezinc has been shown to prevent gastric mucosal injury. The mechanisms of anti ulcer effects of polaprezinc have been thought of its antioxidative actions, cytoprotective effects in gastric mucosa and stimulation of wound healing. The effect of polaprezinc on ionizing radiation-induced apoptosis was studied in the jejunal epithelial crypt cells of rats. Seven- to 8 week-old Wistar rats, which were treated 100 mg/kg of polaprezinc as polaprezinc group or 2 % carboxymethylcellulose sodium (CMC) as control group, were exposed to whole body X-ray irradiation at 2 Gy. The jejunum was resected at 1, 2, 4 and 6 hours after irradiation and immersed in neutral-buffered formalin. After fixation, the jejunum was cut longitudinally and processed for embedding in paraffin blocks. The number of apoptosis was counted in each crypt in H&E-stained sections. Immunopositive cells for TUNEL and active caspase-3 were also counted. Accumulation of p53 and the expression of p21 in jejunum after irradiation was examined by Western blot analysis. Polaprezinc treatment given prior to radiation resulted in the significantly reduction in number of apoptotic jejunal crypt cells, and decreases in p53 accumulation and p21 expression. Polaprezinc has protective effect against ionizing radiation induced apoptosis in jejunal crypt cells by way of p53 pathway.
