Post-hypoxic magnesium decreases nuclear oxidative damage in the fetal guinea pig brain

This study was to determine if administration of MgSO4 after the hypoxic in sult (post-hypoxia) would attenuate neuronal damage in the fetal guinea pig brain. Pregnant guinea pigs (45-60 days gestation) were exposed to hypoxia (7% O-2) for 1 h. Following hypoxia, one group recovered for 24 h with no additional treatment (post-hypoxia) and another group received MgSO4, 300 m g/kg i.p., followed by 100 mg/kg i.p., each hour for three doses (post-hypo xia+Mg) and allowed to recover for 24 h. Fetal brain magnesium content was decreased (P<0.05) 4 h post-hypoxia which was prevented by treatment with M gSO4. High energy phosphates were significantly lower (P<0.05) in the post- hypoxia group which was partially prevented by post-hypoxic magnesium. Na+, K+-ATPase activity was significantly lower (P<0.05) and nuclear membrane fl uorescent compounds were significantly higher (P<0.05) in the post-hypoxia group but were not significantly changed in the post-hypoxia+Mg group compa red with the normoxic control group. DNA fragmentation was observed to be l ower in the Mg-treated post-hypoxic group. This study demonstrates that mat ernal MgSO4 administration following in utero hypoxia prevents associated d ecreases in fetal brain magnesium and suppresses alterations in both the ne uronal and nuclear membranes and genomic fragmentation in the fetal guinea pig brain. (C) 2001 Elsevier Science B.V. All rights reserved.