ABSTRACT
ObjectiveTo explore the mechanism of Naozhenning on learning and memory ability and neuron damage in hippocampal CA1 region of post-concussion syndrome model rats based on mitochondrial function. MethodMultiple cerebral concussion （MCC） was induced in SPF Wistar rats with the free-fall impact method. Then the model rats were randomly classified into model group （equivalent volume of distilled water）， piracetam （0.43 g·kg-1， ig） group， and low-， medium-， and high-dose NZN （5.4， 10.8， 21.6 g·kg-1， respectively， ig） groups， with 10 rats in each group， and another 10 normal rats were included in the normal control group （equivalent volume of distilled water）. The administration lasted 14 days and then relevant indexes were detected. Morris water maze test was used to observe the changes of learning and memory ability in each group， such as escape latency， residence time in primary quadrant， and times of crossing platform. The pathological changes of hippocampal CA1 region were observed based on hematoxylin-eosin （HE） staining and Nissl staining. The ultrastructure of mitochondria was observed under the transmission electron microscope （TME） and the activity of mitochondrial respiratory chain complex Ⅰ was detected by colorimetry. The content of adenosine triphosphate （ATP） was determined by fluorescence probe and mitochondrial membrane potential （MMP） by fluorescein enzyme-linked fluorescence immunoassay. ResultCompared with the normal control group， the model group showed long escape latency， short residence time in target quadrant， few times of crossing the platform， significant decrease in counts of neurons and Nissl bodies in hippocampal CA1 region， damage of neuronal morphology and mitochondrial structure， and significant reduction of MMP and the content of mitochondrial ATP and respiratory chain complex I （P<0.05， P<0.01）. The NZN groups demonstrated short escape latency， long residence time in target quadrant， increased times of crossing the platform， small number of neurons and Nissl bodies in hippocampal CA1 region， alleviated damage of neuronal morphology and mitochondrial structure， and increase in MMP and the content of mitochondrial ATP and respiratory chain complex I （P<0.05， P<0.01）. ConclusionNZN can improve the learning and memory ability of MCC rats by improving mitochondrial structure and function and alleviating hippocampal neuron injury.
ABSTRACT
Objective To set up a system in vitro to rapidly recover plasma proteins lost during artificial-liver treatment.Methods The polyprotein precipitation was obtained by all proteins whose isoelectric point pH value were between 7.3 and 5.1,which collided with each other and aggregated using gradient pH co-precipitation(adding 1 mol/L citric acid slowly in the plasma solution to change the pH values gradually from 7.3 to 5.1 in 5 h)combined with salting out(degree of saturation of NaCl is 33%,reacted for 5.5 h at 4℃)or low-temperature ethanol precipitation(40% ethanol, reacted for 5.5 h at -7℃)so that to get rid of toxicants by discarding the supernatant.Results In the range of pH 5.1-7.3,50%(29g/57g)of the total plasma proteins had been recovered by the gradient pH salting out and 41%(25 g/61g)by the gradient pH low-temperature ethanol co-precipi- tation.The protein remained in the supernatant was mostly albumin and its combined bilirubin.The levels of total bilirubin decreased to 0.07% and 0.06% of the original levels by these two methods respectively and the serum HBV DNA level decreased to be undetected(quantitative PCR).Conclu- sions The proteins with close isoelectric point can co-precipitated with the presence of high concen- tration of NaCl or low-temperature ethanol and by changing the pH value gradually.The total protein in the discarded plasma during artificial-liver treatment can be recovered rapidly using the gradient pH coprecipitation.