| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1992: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
The following results were obtained.
(1) Unlike normal controls, brindled mouse hemizygotes(BMs) exhibit persistently low copper concentration and low activities of cytochrome oxidase(CyO) and superoxide dismutase(SOD) in brain tissue during the postnatal period. Neuronal degeneration due to progressive mitochondrial ballooning proceeds around after postnatal day 8, dopamine-beta-hydroxylase activity in the brain drops almost to zero at about 12 days of age, and BMs die usually around at 15 days old.
(2) By a single subcutaneous injection of 50mug of cupric chloride to BMs on postnatal day 7, activities of CyO and SOD in brain tissue elevate gradually and reach the normal level 6 month(about 170 days) later. Although there are no significant pathologic changes in the brain, the copper concentration shows only a slight elevation and the normal level is not reached; it shows about 60% of the normal level even in BMs surviving until 24 months old.
(3) Monoamine oxidase(MAO) activity in brain
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tissue of normal mice shows an agedependent increase and that of BMs elevates similarly without any decline. This implies that MAO activity is not significantly involved in brain degeneration in Menkes disease.
(4) A new modification from the original method for MAO activity staining by Kishimoto and Arai, has been established. Observations of normal adult mouse brains by this new method have demonstrated that staining of MAO positive neurons(MAO activity) is well preserved until 4 hours after sacrifice if the brain tissue is kept at 4ﾟC, and almost permanently when kept at -70ﾟC. The result indicates that this modification is applicable to human tissue biopsied or autopsied.
(5) Copper injection by any methods after postnatal day 7 cannot rescue BM life. Not only a single injection on postnatal day 7, but also divided injections on postnatal day 5(20 mug) and day 7(30 mug) with or without a booster injection(10 mug) on day 9 can success in prolonging the survival of BMs. However, it is difficult to say that there is a significant difference in macro- and microscopic changes as well as copper-dependent enzyme activity in brain tisse obtained from BMs survived by different therapeutic maneuvers described above. In the case of Menkes patient treatment, however, it is presumed that divided injections, which may prevent renal injuriy(intoxication)by copper-overdose, should bring about a better result. Less
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