| Project/Area Number |
04454117
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
基礎獣医学
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| Research Institution | University of Osaka Prefecture |
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Principal Investigator |
OHTA Mitsuaki University of Osaka Prefecture, Agriculture, Associate Professor, 農学部, 助教授 (20134504)
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| Co-Investigator(Kenkyū-buntansha) |
KISO Yasuo University of Osaka Prefecture, Agriculture, Research Associate, 農学部, 助手 (10142374)
SHIOTA Masakazu University of Osaka Prefecture, Agriculture, Associate Professor, 農学部, 講師 (10137242)
MATSUDA Hiroshi Tokyo Univ.of Agri.and Tech., Agriculture, Assistant Professor, 農学部, 助教授 (80145820)
村上 昇 宮崎大学, 農学部, 助手 (80150192)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1993: ¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1992: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | hyperglycemia / hypoglycemia / insulin / amylin / polymer / catecholamines / hypothalamus / serotonin / マイクロダイアリシス / 神経伝達物質 / ランゲルハンス島 / ノルエピネフリン / インシュリン非依存性糖代謝 |
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| Research Abstract |
To assess the involvement of the sympathetic nervous system in the control of secretion of hormones which affect carbohydrate metabolism and roles of amylin in hyperglycemia or hyperinsulinemia, responses to the implantation of a super-absorbent polymer (SAP) near the ventromedial hypothalamus (VMH) were compared with those to electrolytic lesions in the VMH area.
Electrolytic lesions of the VMH resulted in marked hyperinsulinemia and hyperamylinemia and, at day 7 and later after the operation, an elevation of plasma glucagon lcvel. Epinephrine concentration in the plasma was reduced whereas that of norepincphrine remained unaltcred ; these alterations were accompanied by mild hypoglycemia. Implantation of SAP near the VMH caused opposite changes : decreases in the circulating levels of pancreatic hormones (insulin glucagon and amylin), large increases in circulating catecholamines and mild hyperglycemia. It is suggested that implantation of SAP mimics a state of chronic VMH stimulation. In the latter animals, glucose tolerance after an i. p. injection of the sugar was markedly improved and was associated with decreased levels of plasma insulin. It is postulated that improved glucose tolerance involves stimulation by high levels of circulating catecholamines of insulin-independent pathways participating in sugar disposal from blood. Amylin-implants in SAP-injected rats recovered the glucose tolerance.
The overall conclusion of the study is that the new model of apparent chronic stimulation of the VMH provides strong support for the hypothesis that this region of the brain is an important center in the control of carbohydrate metabolism and blood glucose homeostasis.
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