RESUMO
OBJECTIVE: To study the effect of microwave irradiation on hippocampus cell. METHOD: Changes of ATPase activity and voltage dependent ion channel of hippocampus cell membrane were observed in mice exposed to 2 450 MHz microwave irradiation of 10 mW/cm2 from a physical therapy machine. Histochemical method and patch clamp method were used to determine the activity of Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase and voltage dependent Na+, K+, Ca2+ channels respectively. RESULT: 1) Na+, K(+)-ATPase activity of microwave irradiated mice showed no significant change as compared with the control, but the activity of Ca2+, Mg(2+)-ATPase decreased significantly (P< 0.05); 2) In microwave irradiated mice, Na+, K+, Ca2+, current inducement rate in hippocampus neuron decreased significantly, the membrane voltage of Na+ current peak shifted to depolarization, and the attenuation rate of Na+ current and current A inducement rate decreased significantly as compared with control mice. CONCLUSION: Irradiation of 2 450 MHz microwave at a doze of 10 mW/cm2 was not fatal to mice hippocampus cell. But Ca2+, Mg(2+)-ATPase activity of hippocampal cell membrane and voltage dependent Na+, K+, Ca2+ ion channel of hippocampal nervous were affected which would affect study and memory.
Assuntos
ATPase de Ca(2+) e Mg(2+)/metabolismo , Hipocampo/efeitos da radiação , Canais Iônicos/metabolismo , Micro-Ondas , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , ATPase de Ca(2+) e Mg(2+)/efeitos da radiação , Canais de Cálcio/metabolismo , Canais de Cálcio/efeitos da radiação , Membrana Celular/enzimologia , Membrana Celular/metabolismo , Membrana Celular/efeitos da radiação , Hipocampo/citologia , Hipocampo/enzimologia , Hipocampo/metabolismo , Canais Iônicos/efeitos da radiação , Camundongos , Canais de Potássio/metabolismo , Canais de Potássio/efeitos da radiação , Canais de Sódio/metabolismo , Canais de Sódio/efeitos da radiação , ATPase Trocadora de Sódio-Potássio/efeitos da radiaçãoRESUMO
OBJECTIVE: To study the mechanism of the effects of microwave on learning and memory. METHOD: Long-term potentiation (LTP) of hippocampus induced potential and lipofuscin content in rat brain were studied. After irradiated by a 2450 MHz microwave, rats hippocampus induced potential in vivo was recorded and lipofuscin content in the brain was measured by fluorospectrophotometry. RESULT: Continuous microwave with 10-25 mW/cm2 intensity could inhibit the amplitude of the population spike (PS) of weak and strong stimuli induced LTP with an intensity-effect relationship. At 25 mW/cm2, lipofuscin content was significantly higher than control and 10 mW/cm2 group (P<0.05). CONCLUSION: Continuous microwave with 10-25 mW/cm2 intensity impairs learning and memory by restraining hippocampus LTP and brain lipofuscin content.