ABSTRACT
Objective To observe the expression of neuron specific enolase (NEC) to evaluate the neuroprotective effect of a cell-penetrating Bax-inhibiting peptide (BIP) on neonatal rats with hypoxic-ischemic brain damage (HIBD). Methods Wi-star rats (7-day old) were randomly divided into Sham group, BIP group and HIBD group. After modeling HIBD, the histologi-cal (HE staining) and immunohistochemistry methods were used to determine the apoptotic pathological changes and the NSE expression levels in the brain at different time points. Results Compared to the Sham group, the rats of HIBD group showed significant apoptotic pathological changes. The histological changes and the brain damages were improved significantly in BIP group at each sampling point. The number of NSE-positive cells was significantly decreased in HIBD and BIP groups over time (P<0.05). The number of NSE-positive cells had significant difference among different groups at 48 h, 96 h and 7 d after opera-tion (F=45.35-81.66, P<0.01). The number of NSE-positive cells in the HIBD group was smaller than that of the Sham group and BIP group 48 h after operation (P<0.05). The number of NSE-positive cells in the BIP group was smaller than that of the Sham group 96 h after operation (P<0. 05). Conclusions BIP can decrease the apoptosis of cortex nerve cells in 7-day old HIBD rat model, and may have neuroprotective effect on the early stage of HIBD.
ABSTRACT
Objective To study the effect of hyperbaric oxygen (HBO) therapy on changes in the prolifera-tion of endogenous neural stem ceils (NSCs) in neonatal rats after hypoxie ischemic brain damage (HIBD). Meth-ods A total of 150 Sprague-Dawley rats aged 7 d were randomly divided into a normal eontrol group ( CON ), a HIBD group and a HBO treatment group. HBO was administered to the HBO treatment group within 3 h after HIBD at 2 atmospheres, once daily for 7 d. The HIBD model rats were subjected to unilateral carotid artery ligation followed by 2 h of hypoxia (8% O2> ). BrdU/nestin immunofluorescence was used to examine the proliferation of NSCs dynami-cally in the subventricular zone (SVZ) and the dentate gyms (DG) at the 3rd h, 21st h, 3rd d, 7th d and 14th d af-ter HBO therapy. Nestin protein was detected by Western blot analysis at various time points after HIBD. Results In the HIBD rats treated with HBO, proliferation of endogenous NSCs was observed in the SVZ and DG. The prolifer-ating NSCs increased at the 3rd h and 21st h after HBO therapy in the SVZ and DG respectively, peaked at the 7th d after HBO therapy, and decreased by the 14th d after HBO therapy, though their level was still higher than that in the controls. The Western blot analysis showed that nestin protein began to increase at the 21st h after HBO therapy, peaked at the 7th d after HBO therapy, then decreased. Conclusion HBO administered within 3 h after HIBD can promote proliferation of endogenous NSCs in neonatal rats after HIBD.