Effects Of Diagnostic Color Doppler Ultrasound To The Expression Of Protein Fos And Apoptosis Of Central Neurons In Fetal Rat

Objective: To study whether the expression of protein Fos and cell apoptosis in fetal rat central neurons would be affected when exposed to certain quantity of color Doppler ultrasound in uterus during the late pregnancy period, with that to deduce whether it should be a kind of stimulation to fetus in uterus in late pregnancy period for the exposure of color Doppler ultrasound (no matter harm or not),so as to supply animal experimental foundations for the obstetric application of color Doppler ultrasound.Material and methods: Fifty-eight models of late pregnant SD rats were established. Suitable anaesthetic drugs were chosen. After exposed to color Doppler ultrasound for different time.fetal rats were taken out according to the fixed time points. Accounts to the total fetus number for each mother rat.as well as the malformed and dead fetus.Brain tissues were taken out from fetus to detect the changes of sub-structure and ultrastructure and the expression of protein Fos and cell apoptosis.Results: 1 Poor-stained Fos-positive neurons were seenscattered in the fetal brain hippocampus and cerebral cortex in the 10-min group, while a crowd of robust-stained Fos-positive neurons were seen in hippocampus, cerebral cortex and basal ganglia in 20-min and 30-min groups. 2 The peak expression of protein Fos appeared in 2hr after exposed to color Doppler ultrasound for 30min, then it reduced as time went by. But the expression of protein Fos increased in 24hr once again. 3 Few apoptotic cells were seen in control group and 10-min group .which number increased in 20-min and 30-min groups There were significant differences (P<0.01) between 10-min and the other two exposed groups respectively. 4 Typical apoptotic changes were seen in brain tissue of 30-min group with electron microscope,which showed margination and complete condensation of the nuclear chromatin. 5 With light microscope, only vacuole degeneration was seen when expose for SOmin.Conclusion: The high expression of protein Fos in fetal rat brain could be induced by diagnostic color Doppler ultrasound when exposed for more than 20minutes. The high expression appeared in 2hr and 24hr after exposure.Exposure to diagnostic color Doppler ultrasound over 20minutes may result in cortical neurons apoptosis in brain tissue of fetal rat.