2006 Fiscal Year Final Research Report Summary
Mechanisms responsible for the attenuating effects of estrogen on cardiovascular responses to psychological stress in the central nervous system and the peripheral vessels
| Project/Area Number |
17590202
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Environmental physiology (including Physical medicine and Nutritional physiology)
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| Research Institution | Nara Women's University |
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Principal Investigator |
MORIMOTO Keiko Nara Women's Univ., Facult. Human Life & Environment, Prof., 生活環境学部, 教授 (30220081)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAMATA Akira Nara Women's Univ., Facult. Human Life & Environment, Assoc. Prof., 生活環境学部, 助教授 (00264755)
UEYAMA Takashi Wakayama Med. Univ., Dept. Anatomy & Cell Biol., Assoc. Prof., 医学部, 助教授 (50264875)
KIMURA Hiroko Juntendo Univ., Sch. Med., Forensic Med., Assoc. Prof., 医学部, 講師 (00053299)
YOSHIDA Ken-ichi Univ. Tokyo, Grad. Sch. Med., Forensic Med., Prof., 大学院・医学系研究科, 教授 (40166947)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Psychological stress / Ovariectomized rat / Estrogen / Catecholamine / Oxidative stress / Nitric oxide / Hypothalamic paraventricular nucleus / 4-hydroxy-2-nonenal |
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| Research Abstract |
(1) Sex difference in norepinephrine surge in response to psychological stress through nitric oxide in rats
A mild psychological stress induced by a cage-switch evoked a norepinephrine surge in the male, but not in the female rats. There was a sex difference in the norepinephrine surge in response to psychological stress through nitric oxide (NO), in association with pressor response.
(2) Effects of estrogen on plasma catecholamine, NO metabolites (NOx) and 4-hydroxy-2-nonena1 during cage-switch stress
Estrogen replacement tended to suppress plasma norepinephrine elevation induced by the stress in ovariectomized rat. Additionally, the NO synthase (NOS) inhibitor decreased this effect of estrogen. By Western blotting analysis, estrogen replacement enhanced basal endothelial NOS expression in mesenteries. Furthermore, estrogen replacement attenuated a basal level of plasma 4-hydroxy-2-nonenal, a marker for oxidative stress, and tended to enhance plasma NOx level.
Our results suggest that est
… More
rogen attenuates the stress-induced pressor response by suppressing oxidative stress and enhancing NO bioavailability
(3) Effects of estrogen replacement on neuronal activation induced by cage-switch stress in ovariectomized rat brain
The stress-induced elevations in c-Fos expressions, a marker for neuronal activation, were detected in the following brain areas : lateral septal nucleus, paraventricular hypothalamic nucleus (PVN), dorsomedial hypothalamic nucleus (DMD), arcuate hypothalamic nucleus, paraventricular thalamic nucleus, and locus coeruleus (LC). Estrogen replacement suppressed stress-induced c-Fos expressions in PVN, DMD and LC. In addition, estrogen replacement enhanced the activation of NO-producing neurons in PVN. These findings suggest that estrogen replacement attenuates neuronal activation in these brain areas, at least partly by NO.
These results suggest that estrogen replacement suppresses cardiovascular responses to psychological stress at least partly through its anti-oxidative effect on the periphery and through its inhibitory effect on neuronal activation in the brain of ovariectomized rats. Less
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Research Products
(2 results)
