Abstract: To investigate the effects of pilose antler peptide on learning and memory abilities of mice exposed to microwave radiation and to study its mechanism, learning and memory impairment model of mice was induced by microwave radiation of 2 450 MHz average surface power, 10.0 mW/cm² for 28 d. The irradiated rats were treated with 25, 50, and 100 mg/kg pilose antler peptide by subcutaneous injection for 28 d. The learning and memory ability of mice was tested by Y maze experiment from 29 d to 33 d. After Y maze experiment, all mice were decapitated on 34th d, the contents of aspartic acid (Asp)、γ-aminobutyric acid (GABA), glutamic acid (Glu) and S100B, the activities of Na⁺-K⁺-ATPase, monoamine oxidase-B (MAO-B), level of tumor necrosis factor-α(TNF-α) in the brain of were determined with ELISA, respectively. The activity of superoxide dismutase (SOD) in the brain of mice was detected with xanthine oxidaseassay. The dentate gyrus area of hippocampal organizational structure was observed and analyzed by microscope after HE staining. The results indicated that compared with the control group, the irradiation group could increase the numbers of errors in Y maze experiment, and rise the contents of GABA, S100B and TNF-α, lower the contents of Asp, Glu, increase the activity of MAO-B, lessen the activities of Na⁺-K⁺-ATPase, SOD in the brain of mice (p<0.05 or p<0.01). Compared with the irradiation group, the pilose antler peptide (50, 100 mg/kg) groups could significantly decrease the numbers of errors in Y maze experiment, and effectively reduce the contents of GABA, TNF-α and S100B, improve the activities of Na⁺-K⁺-ATPase, SOD in the brain of mice. The Pilose antler peptide (25, 50, and 100 mg/kg) groups could increase the content of Asp and Glu, lower the activity of MAO-B in the brain of mice (p<0.05 or p<0.01). Pathology found that part of cell volume grew, cytoplasm was loosened and light dyed, part of the nucleus pycnosis was seen in the irradiation group. Compared with the irradiation group, hippocampal organization structure could be improved by pilose antler peptide (100 mg/kg). Experimental results showed that pilose antler peptide (50, 100 mg/kg, for 28 days) could significantly improve the learning and memory ability of mice exposed to microwave radiation. The mechanism may be related to its enhancement of anti-oxidative actions by anti-inflammatory action, further improving levels of neurotransmitters.

Key words: pilose antler peptide, microwave radiation, learning and memory, neurotransmitter, tumor necrosis factor-α, antioxidation