ABSTRACT
Objective To investigate the effects of the aqueous extracts of ganoderma leucocontextum (GLAE) on cognitive decline of aging rats and possible regulation mechanism. Methods Fifty rats were divided into five groups, control group, model group, GLAE low-dose group, GLAE middle-dose group and GLAE high-dose group. Aging SD rat models were made by D-galactose, and then treated continuously with different doses (0, 50, 100, 200 mg/ kg) of GLAE. The novel object recognition and step down test were performed to detect the changes of rats cognitive function. The brain tissue was stained with toluidine blue, Giemsa and HE staining and observed. The cerebral cell DNA damage was detected by comet assay. Expressions of protein kinase A (PKA) / cyclic adenosine monophosphate (cAMP)-response element binding protein (CREB) signaling pathway related factors in brain were respectively detected by ELISA, Western blotting and Real-time PCR. Results Compared with the model group, administration of GLAE could obviously alleviate rats cognitive decline and pathological change. The levels of cell DNA damage reduced markedly (P<0. 05). The contents of cAMP, brain derived neurotrophic factor (BDNF) and nerve growth factor (NGF), and also expression levels of mRNA and protein of PKA, BDNF, NGF, CREB in the brain increased significantly in each medicated group (P<0. 01, P< 0. 05). Conclusion GLAE can improve cognitive function, and its mechanism may be related to activation of brain PKA/ CREB signaling pathway, increase in neurotrophic factor content and inhibition of cell DNA damage.
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Objective To study the correlation between osteoporosis and degeneration of intervertebral disc in the aging rat.Methods Fifty healthy SD rats were fed for twenty-two months in order to build the model of aging rats,the histology of femoral bone,tibial bone and lumbal vertebra was used to observe,then we evaluated the indexes which reflect the degeneration of intervertebral disc including the quantity of collagen type Ⅱ,Ⅹ of intervertebral disc by the immunohistochemistry methods,the relative area of vascular bud,the thickness of calcified layer and un-calcified layer on cartilage endplate and the indexes which reflect the osteoporosis including the thickness ratio of cortical bone,the relative area of bone trabecula,the bone density,the max stress and straining of bone.Results There was moderate or strong negative correlation among the indexes of the degeneration of intervertebral disc including the relative area of vascular bud,the ratio of the un-calcified and the calcified layer,the quantitation of collagen type Ⅱand the indexes of osteoporosis including the thickness ratio of cortical bone,the relative area of bone trabecula,the density of femoral bone and vertebral body bone,the max stress and straining of bone.However,there was moderate or strong positive correlation with the quantitation of collagen type Ⅹ,of which the bone density of vertebral body had the strongest dependablity with collagen type Ⅹ.And the indexes of bone biomechanics including the max stress and straining had no correlation with the indexes of degeneration of intervertebral disc.Conclusion Osteoporosis has negative correlation with the degeneration of intervertebral disc,which is not distributed to the environment factors;but the indexes of bone biomechanics including the max stress and straining have no correlation with the indexes of degeneration of intervertebral disc.
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By morpometric and immunohistochemical methods, it is observed that the volume density, the numerical density on area and the numerical density of specific granules in the perinuclear region of the atrial myocytes in the aging rats ars significantly less than that in the young groups (p
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The aging changes in tyrosine hydroxylase(TH) -like neurons of the brainstem raphe nuclei in young (2 months), adult(10 months) and old(24 months) rats were examined combining the immunogold-silver staining(IGSS) and the image quanitative analysis. In the raphe nuclei, TH-like neurons were mainly localized in the nucleus raphe dorsalis, nucles centralis superior and nucleus linealis oralis. Number of the neurens in the all nuclei began to be lost significantly from the adult, (?) the old, the number reduced by almost 1/3(P
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Combining the immunogold-silver staining (IGSS) method with the image quantitative analytical study, changes in somatostatin(SOM)-like, neurons of the hippocampal formation were investigated in young (2 monthes), adult (10 monthes) and old (24 monthes) rats. The results were as follows:1. The number of the SOM-like neurons decreased gradually from the young to the old. Moreover, there was a significant difference among the three age groups (p
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Changes in SOM-like neurons of the hippocampal formation were investigated inWistar male rats(young-2 months old;adult-10 months old;aged-24 months old)by using the combination of the IGSS method and image quantitative analysis.The following results were obtained:1.Number of SOM-like neurons decreased markedly(P