Objective To observe the changes of synaptosome membrane fluidity and
intrasynaptosome free calcium in
ovariectomized rats'
brain and the therapeutical effects of genistein. Methods Thirty-six 3 month-old female Sprague-Dawley rats were randomly assigned to 4 groups:sham-operated,
ovariectomized control,genistein and estradiol benzoate groups.Normal saline(50?μl),normal saline(50?μl),genistein(250?μg)and estradiol benzoate (50?μg)were subcutaneously injected respectively once every other day for 8 weeks,and then synaptosome membrane fluidity and
intrasynaptosome free calcium in frontal and parietal lobe and hippocampus were detected. Results The intrasynaptosome free calcium of cerebral cortex and hippocampus synaptosomes of ovariectomized control group (±s)are (243.31±31.21)nmol/L and (305.10±54.31)nmol/L respectively.There are significantly statistical differences as compared ovariectomized control group with sham-operated,genistein and estradiol benzoate groups(P<0.01),but no statistical differences among sham-operated,genistein and estradiol benzoate groups were seen(P>0.05).The synaptosome membrane viscosity(η)of hippocampal synaptosomes of ovariectomized control group(±s)is 3.03±0.39,which has significantly statistical differences compared with sham-operated and estradiol benzoate groups(P<0.05),and compared with genistein group (P<0.01),but no statistical differences among sham-operated,genistein and estradiol benzoate groups(P>0.05).Conclusion The synaptosome membrane fluidity decreased while intrasynaptosome free calcium increased in ovariectomized rats' synaptosomes.Genistein can enhance the membrane fluidity and maintain intrasynaptosome free calcium in ovariectomized rats' synaptosomes.