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Objective: To investigate the possible role of astrocytes after brain infarction in stroke-prone, spontaneously hypertensive (SHR-SP) rats and the association with angiogenesis and the architecture. Methods: We maintained SHR-SP rats on high sodium water starting to accelerate the stroke onset. The 3D quantification of microvasculatures (diameter, branch number) by cofocal microscope after FITC-dextran was injected into the rats via the left femoral vein. Glial fibrillary acidic protein (GFAP) expression and microvessel density (MVD) using counting the number of factor -positive endothelial cells were evaluated by immunofluorescence and immunohistochemistry, respectively. Results: Cerebral infarction occurred at week 7 after high sodium water intake (13 g/L NaCl) in SHR-SP group. When compared with the non-infarcted contralateral hemisphere and SHR-SP on normal sodium intake and WKY rats, GFAP expression and MVD were significantly increased, respectively, and the diameter and the branch number of vessels were decreased, respectively, in cerebral infarcts with boundary zones of SHR-SP rats (P<0.01). Linear correlation analysis showed that GFAP expression was positively correlated with MVD and the diameter and the branch number of vessels in cerebral infarcts in SHR-SP (P<0.01). Conclusion: Astrocytes hyperplasia may be associated with increased regional angiogenesis and the changes of architecture in SHR-SP rats with high sodium water (13 g/L NaCl) that induces focal cerebral infarcts.
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<p><b>OBJECTIVE</b>To establish a bone metastasis model of prostate cancer by intratibia injection of Du145 in nude mice, observe the local growth of tumor in tibia and then assess application value of this model.</p><p><b>METHODS</b>For 9 male nude mice, Du145 (5 x 10(6)) was injected in tibia by a TB syringe with a 29-gauge needle at a dose of 30 microl per mouse. Then the vital signs of the nude mice were observed. When the mice were dying, they were sacrificed, and the tissues of right hindlimbs, lymphatic nodes, lungs and livers were taken out, fixed in 10% formalin, embedded in paraffin, stained by HE and then observed microscopically.</p><p><b>RESULTS</b>Incidence of bone tumor after intratibia injection was 67% (6 out of 9). About 48 days later, there were some small palpable nodes in right hind-limbs of the 6 mice and they couldn't walk normally. About 55 days later, cachexia occurred in them. After dissection, some carrion-like tissue grew from marrow cavity to muscular spatium, which was identified as tumor tissue by HE. The envelop of livers became crampy, and acute hepatitis could be diagnosed through microscopy, which represented a large scale of hepatocytic death, liver sinus dilatation and hyperemia, hepatic lobule infiltrated by lymphocyte, macrophage and inconspicuous hyperplasia. Since hypohepatia occurred too early, we couldn't detected distant metastases.</p><p><b>CONCLUSION</b>The intratibia injection model is an optimal animal model to study metastasis of prostate cancer. It mimics the natural situation of human prostate cancer and will help to understand the mechanisms of androgen-independence and osseous metastasis, and tumor-host determinants of PSA expression.</p>