| Research on aging has been popular not only in clinical medicine but in base medicine as well. As the social population aging, research on brain aging has become a hotspot To discuss the mechanism of brain aging, changes of brain somatostatin(SS) has become one of those widely studied neuropeptides. SS is a cyclic poly peptide of 14 amino acids. Elaborate experimental studies have shown that SS neurons in the hippocampal formation of limbic system are not directly related with the GH secretion and releasing in the Pituitary anterior lobe, but closely related to the function of memory and it plays a significant role in the learning process.TSPG(total saponins of panax ginseng) as the main active components of the traditional Chinese herb panax gingseng, is widely studied as an antiaging agents all over the world. Lots of research work has supported that TSPG can effectively reduce aging degeneration of central nervoussystem. It has been also reported that TSPG can enhance the C-fos gene expression in hippocampus of aged rats. However, little is known aboutthe effects of TSPG on SS of hippocampus in aged rats.In present study, the effects of TSPG on hippocampal SS in aging modelrats induced by D-galactose were observed with ABC immunohistochemicaltechnique and image quantitative analysis .MATERIALS AND METHODS1. Animal groupsEighteen male Wistar rats were randomly divided into three groups (6 each ):normal control(Group A), aging model control induced by D-galactose subcutanious injection(Gruop B) and TSPG treated group (Group C)respectively.2. Aging Model construction and MedicationGroup A: Saline 2ml/kg"d i.h, for6weeks Group B: D-galactose48mg/kg'd i.h. for 6 weeksGroup C: D-galactose 48mg/kg'd i.h and meanwhile TSPG 50mg/kg'd administered orally for 6 weeks3. Tissue section of HippocampusAnimals were anethitized with sodium rjentobarbital(46mg/kg, ip). Open chest and 4% triformol was used to perfum through ascending aorta. Brain tissue were taken out immediately and put into 4% triformol for post fix (6-8h). After routine paraffin dressing, continuous cronal sections of hippocampus were made withLeitzl512 microtome (thickness: Sum).4. Ditect hippocajnpal SS with ABC innnunohistochemical techniqueHippocampal SS of all rats were ditected wilh ABC Kit from Sino-American Biotech Co. Meanwhile , both positive and negative control were done to assure the reliability of ABC findings.5. 1 mage quantitative analysisFor each specism, two slices with the same cross section were analyzied by HP1AS-1000 (High resolution Pathological Image Analysis System) . Integrated optical density (IOD) of DAB-stained hippocampal SS neurons were measured in CAK CA3, CA4&DGrepectively.6. Data processing and statistical analysisData were expressed as Mean ?Standard Deviation. One-way analysis of variance (one-way ANOVA) were applied for multiple comparison between each group. Difference were considered significant at a p<0.01 level.RESULTS AND DISCUSSION1. Comparison! of image quantitative analysis resultsTable 1 Hippocampal SS neurons counting (/mm2)Group n CA1CA3 CA4&DGA689.17?6.55A11633+11.83 A 183.67?3.18A ~B635.00?.94**58.17+8.13** 68J3?^9**C679J3+&94A107.17?3.83A**ComparewimGroupAP<0.01; ACompare with Group B, P<0.01Table 2 IOD of hippocampal SS neuronsGroup n CA1CA3 CA4&DGA612.70?.33Ali62?.69A13.48?.58AB66.99?.61**6.93?34**7.20?.44**C612.25+1.43A12.47?.46A12.59?36A**ComparewithGroupAP<0.01; AComparewithGroupB, P<0.01 From table 1 and table 2, it is obvious that both quantity and IOD of hippocampalSS neurons in Group C (TSPG treated) are significantly higher than that of GroupB( Aging Model)(p<0.0l), and there's no statistic difference between GroupA( Control Group) and Group C. These suggested that TSPG might protect thehippocampal SS-ergic system against D-g... |
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