ABSTRACT
Objective To investigate the protective function and its mechanisms of eyclosporin A to immature brain tissue with convulsive brain damage. Methods 21-day-old SD rats were given lithium-pilocarpine to make the epilepsy model. Total 67 male rats had been investigated. Cyclosporin A (CsA) were injected three times at 6, 30, 54 hrs after model had been established. Three dosages had been chosen: 5, 10 and 25 mg/kg each time. The level of apoptotic cells, P-glycoprotein (P-gp), glial fibrillary acidic protein (GFAP) in CA1 area of hippocampus had been determined, and compared with the rats without giving CsA. Results Rats from epilepsy model group had higher level of apoptosis, P-gp, GFAP expression than those from pseudo-model group. CsA injection by dose 5 mg/kg each time for three times reduced the level of P-gp, GFAP. Model group and pseudo-model group were same. Both the interventions of CsA injection by 10 mg/kg and 25 mg/kg can reduce the level of P-gp, GFAP, however neither of their effectiveness was better than CsA 5 mg/kg each time. Conclusions Small dosage of CsA may protect the immature brain tissue from convulsive brain damage by reducing the level of P-gp, GFAP in CA1 area of hippocampus.
ABSTRACT
Objective Recent studies in neonatal animals have shown that even slightly decreasing in brain or core temperature could ameliorate the damage resulting from hypoxic-ischemia insults. But the influence of hypothermia which had been used after the end of hypoxia-ischemia of the model hypoxia-ischemia brain damage(HIBD)was unknown. This research wanted to investigate whether hypothermia of defferent begin time after HIBD still could protect the brain in neonatal rats. Methods Pericranial temperatures were adjusted to 31 C in neonatal rats immediately or 2h after the end of hypoxia-ischemia(HI),the number of apoptosis cells in HIBD rats' brain had been counted,rat pups' storing food ability had been observed. Results Apoptosis increased obviously when rat pups were 8 days old, while hypothermia reduced apoptosis ,and postponed apoptosis expression in group that 31 C hypothermia was used immediately or 1h after the end of HI,and hypothermia improved the rat pups' storing food ability. This effect was more obviously in the group that hypothermia was used immediately after the HI than in the group that hypothermia was used 1h after the HI. But the protective effect was not clear in the group that hypothermia was used 2 h after the HI. Conclusion Hypothermia which was used within 1h after the end of HI could protect the HIBD neonatal rat pups brain, this effect was more obviously in the hypothermia be used early after the end of HI group than in the hypothermia be used late after the end of HI group.