Brain mechanism by which estrogen enhances fasting-induced suppression of reproductive function

雌激素增强禁食引起的生殖功能抑制的脑机制

• 批准号: 11660283
• 负责人: TSUKAMURA Hiroko
• 金额: $ 2.37万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11660283/
• 关键词: estrogen; receptors; hypothalamic paraventricular nucleus; solitary tract nucleus; fasting stress; luteinizing hormone (LH); noradrenergic neurons; glucose; 黄体形成ホルモン; fasting; motilin; glucokinase; glucose transporter; estrogen; stress; mel

Fasting-stress profoundly suppresses luteinizing hormone (LH) secretion in the rat in an estrogen dependent manner. It has been demonstrated that 48-h fasting significantly increased numbers of estrogen receptor-containing cells in both the hypothalamic paraventricular nucleus (PVN) and A2 region of solitary tract nucleus (NTS) in the lower brain stem. The present research aimed to investigate the brain mechanism by which estrogen enhances fasting-induced suppression of LH secretion.Changes in the number of estrogen receptor α (ERα)-containing cells by fasting and pharmacological glucoprivation were investigated in the PVN and NTS of ovariectomized rats. It has been also determined that the anatomical relationship of ERα immunoreactivity within tyrosine hydroxylase (TH)- and dopamine-β-hydroxylase (DBH)-ir neurons in the A2 region of the NTS and the PVN.The number of ERα-ir cells significantly increased after 30 h from the onset of fasting in the PVN and NTS compared with the unfasted controls and was sustained until 48 h. Glucoprivation also significantly increased the number of ERα-ir cells in these nuclei. Forty-eight h fasting and glucoprivation significantly increased ERα-containing TH-/DBH-ir cells. In the PVN, most ERα-ir neurons were juxtaposed with TH- and DBH-ir varicosities. These results suggest that ERα is expressed in specific brain regions at a defined time from the onset of fasting, and that lowered glucose utilization might be the key signal mediating this fasting-induced changes in ERα expression. In addition, the anatomical relationship of noradrenergic and ERα-ir neurons in the A2 region and PVN may suggest a role for estrogen in increasing the activity of noradrenergic neurons in the A2 region and the sensitivity of the PVN to noradrenergic input arising from the lower brainstem and thereby augmenting the suppression of LH secretion during fasting.

禁食的压力以雌激素依赖性的方式深刻抑制大鼠中的黄体生成马酮（LH）分泌。已经证明，在下脑干的下丘脑室核核（PVN）和固体核核（NTS）的A2区域中，有48小时的禁食显着增加了雌激素受体的细胞数量。本研究旨在研究雌激素通过禁食和药物糖糖尿糖尿病的雌激素受体α（ERα）细胞数量的变换，研究了雌激素受体α（ERα）的细胞数量，并研究了卵巢切除术大鼠的PVN和NTS。还已经确定，酪氨酸羟化酶（Th） - 和多巴胺-β-羟化酶（DBH）-IR神经元在NTS和PVN的A2区域的解剖学关系和多巴胺-β-羟化酶（DBH）-IR神经元在PVN的A2区域中的神经元。 48 h。葡萄糖剂还显着增加了这些核中ERα-IR细胞的数量。 48 h禁食和葡萄糖保护显着增加了含ERα的TH-/DBH-IR细胞。在PVN中，大多数ERα-IR神经元与TH-和DBH-IR静脉曲张并列。这些结果表明，从禁食开始时，在定义的时间内在特定的大脑区域表达ERα，而降低的葡萄糖利用可能是介导这种禁食引起的ERα表达变化的关键信号。此外，A2区域和PVN中去甲肾上腺素能和ERα-IR神经元的解剖学关系可能暗示雌激素在增加A2区域的去甲肾上腺素能神经元的活性以及PVN对降低脑干和此处的降低脑系统和此期间的抑制作用的敏感性的作用。

项目成果

Maekawa,F.: "Prevention of inhibitory effect of dorsal raphe nucleus lesioins on ovulation and LH surge by 5-HT 2A/2C receptor agonists in female rats."Neuroscience Research. 291-298 (2000)

Maekawa,F.：“通过 5-HT 2A/2C 受体激动剂预防雌性大鼠中缝背核损伤对排卵和 LH 激增的抑制作用。”神经科学研究。

Tsukamura, H., Tsukahara, S., Maekawa, F., Moriyama, R., Reyes, B.A.S., Sakai, T., Niwa, Y., Foster, D.L.and Maeda, K.-I.: "Peripheral or central administration of motilin suppresses LH release in female rats : a novel role for motilin."Journal of Neuroen

Tsukamura, H.、Tsukahara, S.、Maekawa, F.、Moriyama, R.、Reyes, B.A.S.、Sakai, T.、Niwa, Y.、Foster, D.L. 和 Maeda, K.-I.：“外周或中枢

Maekawa,F.: "Prevention of inhibitory effect of dorsal raphe nucleus lesioins on ovulation and LH surge by 5-HT 2A/2C receptor agonists in female rats."Neuroscience Research. 35. 291-298 (1999)

Maekawa,F.：“通过 5-HT 2A/2C 受体激动剂预防雌性大鼠中缝背核损伤对排卵和 LH 激增的抑制作用。”神经科学研究。

Ichihara,G.: "Reproductive toxicity of 1-bromopropane, a newly introduced alternative to ozone-layer depleting solvents, in male rats."Toxicological Sciences. 54. 416-423 (2000)

Ichihara,G.：“1-溴丙烷（一种新推出的消耗臭氧层溶剂的替代品）对雄性大鼠的生殖毒性。”毒理学科学。

Tsukahara,S.: "Effect of corticotropin-releasing hormone antagonist on oestrogen-dependent glucoprivic suppression of luteinizing hormone secretion in female rats."Journal of Neuroendocrinology. 11. 101-105 (1999)

Tsukahara,S.：“促肾上腺皮质激素释放激素拮抗剂对雌性大鼠黄体生成素分泌的雌激素依赖性糖皮质激素抑制的影响。”神经内分泌学杂志。