1989 Fiscal Year Final Research Report Summary
Cellular mechanism of stroke - Characteristics of astroglia from the brain of stroke-prone SHR
| Project/Area Number |
63570165
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Experimental pathology
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| Research Institution | Shimane Medical University |
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Principal Investigator |
NARA Yasuo 島根医科大学, 医学部, 助手 (80116417)
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| Project Period (FY) |
1988 – 1989
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| Keywords | Astroglia / stroke-prone SHR / hypertension |
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| Research Abstract |
Astroglia cells were separated from whole brains of fetal stroke-prone SHR(SHRSP), stroke-resistant SHR(SHRSR) and Wistar Kyoto rats(WKY). Over 95% of the population in all strains was positively stained with antiglial fibrillary acidic protein. There was no morphological change in cultured astroglia cells among three strains. The proliferative activity of astroglia cells was significantly greater in SHRSP and SHRSR than that of WKY. When quiescent astroglia in G_1 phase were exposed to fetal calf serum, a linear increase in [^3H] thymidine was observed after a 9-12h lag period. Although the length of lag period did not seem to be different among three strains, the rate of thymidine incorporation in SHRSP cells was greater than that into WKY cells. SHRSR cells showed the intermediate incorporation between SHRSP and WKY. Similar results were observed in cultured vascular smooth muscle cells from SHR and WKY. Total cholesterol levels in SHRSP and SHRSR were significantly decreased compared to that of WKY. The activities of cholesterol biosynthesis from [^<14>C] acetate or [^<14>C] mevalonate were compared among three strains. The formation of cholesterol from acetate was decreased in SHRSP and SHRSR, however there was no difference in cholesterol biosynthesis from mevalonate among three strains. Astroglia has an alpha receptor and Ca^<++> level in the cell was increased by an alpha-agonist. Cellular Ca^<++> level was dose-dependently increased after treatment of phenylephrine (10^<-5>-10^<-7>M) in three strains and the responsiveness to the stimulation was higher in SHR than that of WKY. These abnormalities, noted also in cultured vascular smooth muscle cells may be of rather general phenotype in SHR.
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