Experimental Research On Effect Of Hyberbaric Oxygen On Lipid Peroxidation Of Normal Pregnant Rabbits And Fetal Rabbits

Objectives To investigate effect of therapeutic dosage for hyberbaric oxygen (HBO) on lipid peroxidation (LPO) of normal pregnant rabbits and fetal rabbits, and ultrastructure of placenta, so as to present the theory of using HBO safely in clinical obstetrics.Methods 16 pregnant rabbits were divided into experimental group and control group randomly, 8 for each group. Blood plasma of the pregnant rabbits of the two groups were taken out and stored on the 20th day of gestation. The pregnant rabbits of the experimental group were exposed to 80% oxygen at 2 ATA one hour every day from the 21st day of gestation to the 30th day of gestation, while the control group was raised in normal pressure atmosphere at the same time. Blood plasma of the pregnant rabbits of the two groups were taken out and stored , and the fetal rabbits of the two groups delivered by caesarean on the 30th day of gestation right after the experimental group finished HBO therapy. Birth weight of the fetal rabbits of the two groups were measured when being born. 2 fetal rabbits were selected randomly from the fetal rabbits delivered by each pregnant rabbits. Placenta tissues, blood plasma and brain tissues of these fetal rabbits were taken out and stored. 8-iso-prostaglandin F2α(8-iso-PGF2α) and superoxide dismutase (SOD) were measured in blood plasma of the pregnant rabbits of the two groups before and after the experimental group being exposed to HBO, and these index were also measured in blood plasma, brain tissues and placenta tissues of the fetal rabbits of the two groups. Ultrastructure ofplacenta of the two groups were observed by electron microscopy. Sycytial mitochondria in synthetic areas of placenta were stereologically studied on electron level.Results Contents of 8-iso-PGF2α and SOD in blood plasma of the pregnant rabbits of the two groups on the 30th day of gestation were higher than those on the 20th day of gestation (.P<0.05) ; however contents of 8-iso-PGF2α in blood plasma of the pregnant rabbits of the two groups were not different after the experimental group being exposed to HBO (P>0.05) ; contents of SOD in blood plasma of the pregnant rabbits of the experimental group were significantly elevated than those of the control group (P<0.001); contents of 8-iso-PGF2α in blood plasma, brain tissues and placenta tissues of the fetal rabbits of the two groups were not changed (P>0.05) ; while the contents of SOD in blood plasma, brain tissues and placenta tissues of the fetal rabbits of the experimental group were significantly elevated than those of the control group (P<0.001) ; there were no differences between the ultrastructure of placenta of the two groups (P>0.05) ; there were no differences between volume density, surface density, ratio of surface to volume, numerical density and mean volume of sycytial mitochondria in synthetic areas of placenta of the two groups (P>0.05) ; the same with the birth weight of the fetal rabbits of the two groups (P>0.05) .Conclusions Contents of 8-iso-PGF2α and SOD in blood plasma of normal pregnant rabbits change with the tendency of increasing as the weeks of gestation followed during late gestation. Therapeutic dosage for hyberbaric oxygen during pregnancy can elevate the activities of antioxidant enzymes to get rid of overfull oxygen free radical in normal pregnant rabbits and fetal rabbits, therefore it cannot influence the contents of LPO. It also does no harm to the ultrastructure of placenta of the rabbits, neither does it do harm to the fetal rabbits' growth.