| Budget Amount *help |
¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000)
Fiscal Year 2011: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2010: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2009: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
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| Research Abstract |
In brown adipocytes,-adrenergic activation evokes Ca^<2+> release from the endoplasmic reticulum(ER) and store-operated Ca^<2+> entry(SOC) in brown adipocytes, while.-adrenergic activation causes mitochondrial Ca^<2+> release via uncoupling of oxidative phosphorylation, which activates Ca^<2+>-induced Ca^<2+> release from the ER, SOC, and a novel uncoupling-linked Ca^<2+> entry. We studied how these two modes of adrenergic Ca^<2+> signaling pathways interact with each other by recording cytoplasmic Ca^<2+>([Ca^<2+>]_i), mitochondrial membrane potential and the Ca^<2+> concentration in the ER([Ca^<2+>]_<ER>) by fluorometry. The rise in [Ca^<2+>]_i and the reduction of [Ca^<2+>]_<ER> evoked by phenylephrine was depressed under the full effect of a-agonist, BRL37344, while they were enhanced under the weak action of BRL37344.On the other hand, the second and/or third components of the bi-or triphasic rises in [Ca^<2+>]_i induced by BRL37344 was depressed under the effect of the subthreshold concentration of phenylephrine. Thus, when the-action is strong enough to cause a large rise in [Ca^<2+>]_i, it was suppressed during the late phase of the-action for the decreased Ca^<2+> content in the ER. On the other hand, when the-action is weak not enough to release Ca^<2+> from the ER presumably due to an inadequate rise in IP_3 concentration, the rises in [Ca^<2+>]_i by mitochondrial Ca^<2+> release would boost the activation of IP_3 receptor at the ER membrane.
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