Objective To evaluate the effects of isoflurane postconditioning on mitochondrial permeability transition pore (mPTP) in brain tissues of neonatal rats with hypoxic-ischemic brain injury.Methods One hundred and twenty 7-day-old Sprague-Dawley rats,weighing 12-16 g,were randomly divided into 4 groups (n =30 each) using a random number table:sham operation group (group S),isoflurane group (group I),hypoxicischemic brain injury group (group HIBI),and hypoxic-ischemic brain injury + isoflurane postconditioning group (group HI).To establish hypoxic-ischemic brain injury model in the neonatal rats,the left common carotid artery ligation was carried out,and then the rats were exposed to 8％ O2 + 92％ N2 at 37 ℃ for 2 h in HIBI and HI groups.The rats inhaled 1.5 ％ isoflurane for 30 min after the model was established in group HI.The rats only inhaled 1.5％ isoflurane for 30 min in group I.At 24 h after the model was established,10 rats taken out randomly in each group were sacrificed and brains were removed to detect mPTP opening.At 7 days after the model was established,the survival rate was recorded in the rest rats.The rats were then sacrificed and brains were removed and the right and left cerebral hemispheres were weighed separately,and the ratio between left/right cerebral hemispheres was calculated.The density of normal neurons in ventral posterior inferior thalamic nucleus and hippocampal CA3 region in the left and right cerebral hemispheres were measured and the ratios of the density of normal neurons in the left to right cerebral hemisphere were calculated.Results There was no significant difference in the survival rate between the four groups (P ＞ 0.05).Compared with group S,the ratios of the density of normal neurons in the left to right cerebral hemisphere,weight of left cerebral hemisphere,and ratio between left/right cerebral hemispheres were significantly decreased,and mPTP opening was increased in group HIBI (P ＜ 0.05),and no significant changes were found in the parameters mentioned above in group I (P ＞ 0.05).Compared with group HIBI,the ratios of the density of normal neurons in the left to right cerebral hemisphere,weight of left cerebral hemisphere,and ratio between left/right cerebral hemispheres were significantly increased,and mPTP opening was decreased in group HI (P ＜ 0.05).Conclusion The mechanism by which isoflurane postconditioning reduces hypoxic-ischemic brain injury may be related to inhibition of mPTP opening in brain tissues of neonatal rats.

The corn germ protein tested was a by-product from, corn starch plant and it contained more lysine (average 5.7%) and a relatively ideal proportion of eight essential amino acids similar to the 1973 FAO/WHO provisional amino acid pattern. A 5-week rat growth experiment was conducted to evaluate the nutritive value of corn germ protein by using body weight gain, nitrogen balance and apparent net protein utilization as assessment criteria.The feed of the experimental group was made of wheat protein supplemented with 17.3% germ protein and that of the control with 2.4% wheat glu- ten to made the final protein level of both feeds equivalent to 10%.These results showed that the body weight gain of rat in the experimental group was higher than that of the control group regardless of female or male, the body weight gain per 100g feed consumed in two groups of female was 19.0g and 12.2g and that of male was 17.6g and 10.4g respectively (p

Objective To evaluate the effects of isoflurane postconditioning on long-term cognitive function of neonatal rats with hypoxic-ischemic brain injury (HIBI).Methods Sixty 7-day-old Sprague-Dawley rats,weighing 12-16 g,were randomly divided into 4 groups (n =15 each) using a random number table:sham operation group (group Ⅰ),isoflurane postconditioning group (group Ⅱ),cerebral hypoxia-ischemia group (group Ⅲ),and isoflurane postconditioning after cerebral hypoxia-ischemia group (group Ⅳ).Brain ischemia was induced by permanent ligation of the left common carotid artery followed by inhalation of 8 ％ O2-92 ％ N2 for 2 h at 37 ℃ in Ⅲ and Ⅳ groups.In Ⅰ and Ⅱ groups,the left common carotid artery was only isolated but not ligated.The rats inhaled 1.5％ isoflurane in 30％ O2-70％ N2 for 30 min starting from 2 h of hypoxia in Ⅱ and Ⅳ groups.The rats were exposed to 30％ O2-70％ N2 for 30 min in Ⅰ and Ⅲ groups.Morris water maze test was carried out at 30-35 days after HIBI.The escape latency,swimming speed,swimming distance,the number of times the animals crossing the platform quadrant,the percentage of time spent in the platform quadrant and the percentage of swimming distance in the platform quadrant were recorded.The animals were sacrificed after Morris water maze test.The density of normal neurons in ventral posterior inferior thalamic nucleus and hippocampal CA3 region in left and right cerebral hemisphere was measured and the ratio of the density of normal neurons in the left to right cerebral hemisphere was calculated.Results Compared with group Ⅰ,the escape latency was significantly prolonged at 30-34 days after HIBI in group Ⅲ and at 31 and 34 days after HIBI in Ⅳ group,the number of times the animals crossing the platform quadrant,percentage of time spent in the platform quadrant,percentage of swimming distance in the platform quadrant,and ratio of the density of normal neurons in the left to right cerebral hemisphere were decreased at day 35 after HIBI in group Ⅲ,no significant changes were found in the number of times the animals crossing the platform quadrant,percentage of time spent in the platform quadrant,and percentage of swimming distance in the platform quadrant,and the ratio of the density of normal neurons in the left to right cerebral hemisphere was decreased at day 35 after HIBI in group Ⅳ,and no significant changes were found in the parameters mentioned above in group Ⅱ.Compared with group Ⅲ,the escape latency was significantly shortened at 31-34 days after HIBI,and the number of times the animals crossing the platform quadrant,percentage of time spent in the platform quadrant,percentage of swimming distance in the platform quadrant,and ratio of the density of normal neurons in the left to right cerebral hemisphere were increased at day 35 after HIBI in group Ⅳ.There was no significant difference in the swimming speed and swimming distance at day 35 after HIBI between groups.Conclusion Isoflurane postconditioning can improve long-term cognitive function of neonatal rats with HIBI.