Expression Of Lingo-1mRNA And Change Of Apoptosis In Brain Tissue Of Newborn PVL Rats

ObjectiveTo set up PVL model for 2d SD rats and to observe the apoptosis and expression of Lingo-1mRNA in the brain tissues of neonatal rats with PVL. To investigate the correlations between the sham surgery group and the PVL model group. Explore the significance of Lingo-1 in PVL and the mechanism of PVL.MethodsA total of 160 rats were randomly divided into experimental group (86) and control group(74). After establishment of PVL model for 2d SD rats, DAPI colorated method was used to calculate the percentages of neuron apoptosis in the brain tissues and the Real time PCR method was applied to detect the changes in the expressions of Lingo-1mRNA at the different time.Results1. Observed by light microscope: In the sham surgery group, brains cells were arrayed in an orderly manner with big nucleus; while in the PVL group, the pathological changes of brain tissues included cellular swelling, pyknosis, reticular necrosis and so on in early period of hypoxic-ischemic(HI). The ventricular dilatation and the empty vesicle had been found 7d after HI. 2. Changes of neuron apoptosis: Little apoptosis was observed in striatum zone and callosum zone of the sham surgery group. Apoptosis index in experimental group began to increase at 8h, peaked at 48h and slightly decreased but remained at a higher level at 72h than that of the sham surgery group (P＜0.05). Apoptosis index declined significantly and have statistically insignificant compared with the sham operation group at 7d (P＞0.05).3. Expression of Lingo-1mRNA: Except the expressions of Lingo-1mRNA at Oh is higher than that at 7d(P＜0.05), there was not obvious changes at other time and the difference of statistically significant was not found in the sham surgery group. Compared with the sham surgery group, its expression of the PVL group increased within 8h, reached the peak value at 48h, remained higher level at 72h than that of the sham surgery group(P＜0.05), and then declined, and the statistically insignificant was not found at 7d(P＞0.05) in comparison with the sham surgery group.Conclusions1. After the unilateral ligation of right carotid artery and intake of 6％oxygen and 94％nitrogen for 4 hours, the pathological changes of brain tissues have been proved to accord with PVL by the neural behavior and the weight and by the observation under light microscope.2. The apoptosis index in the brain tissues of the immature SD rats with PVL showed the tendency of rise before decline and its process was in order, which suggests that the apoptosis may participate in the pathologic process of PVL.3. In the sham surgery group, the expression of Lingo-1 mRNA decreased before matured, but the tendcy of rise before decline in PVL group was observed. The changes of expression of Lingo-1mRNA accorded with that of apoptosis. It suggests Lingo-1 could accelerate the process of apoptosis, which activated its signaling pathway and inhibited the regeneration of central nerves.