雌激素会损害由血管活性肠诱导的低性和下丘脑细胞激活,但不是由 pituitary adenylate cyclase-activating polypeptide诱导的
Marcela Cristina Garnica-Siqueira1, Andressa Busetti Martins2, Érica Cristina Alves Munhoz Monteiro3
1Laboratório de Fisiologia, Hospital de Reabilitação de Anomalias Craniofaciais, Universidade de São Paulo, Bauru, SP, Brazil; Programa Multicêntrico de Pós-Graduação em Ciências Fisiológicas, Universidade Estadual de Londrina, Londrina, PR, Brazil.
Peptides
|December 1, 2024
概括
在卵巢切除的老鼠中,雌激醇会破坏由血管活性肠 (VIP) 引起的食物摄入量减少. 这种效应与弧形 - 准腹腔通路的激活受损有关,突出显示雌激素.
科学领域:
- 神经内分泌学神经内分泌学
- 能量恒常状态 (Energy Homeostasis) 是一种能量的恒常状态.
- 荷尔蒙的调节 荷尔蒙的调节
背景情况:
- 神经贝血管活性肠 (VIP) 和 pituitary adenylate cyclase-activating polypeptide (PACAP) 影响在下丘脑中的食和新陈代谢.
- 雌激素 (E) 对于调节能量平衡至关重要,卵巢功能丧失导致食欲增加和体重增加.
- 大鼠的卵巢切除 (OVX) 模仿了绝经后的情况,影响了荷尔蒙平衡和能量平衡.
研究的目的:
- 为了研究雌激醇 (E) 对卵巢切除 (OVX) 鼠的弧形 (ARC) 和副腹腔 (PVN) 核中的VIP和PACAP信号的影响.
- 评估E对食物摄入,血参数和神经元激活对VIP和PACAP的反应的影响.
- 确定E如何影响ARC和PVN中的PAC1和VPAC2受体的表达.
主要方法:
- 卵巢切除的老鼠被用玉米油 (OVX+O) 或雌二醇酸 (OVX+E) 治疗.
- 对VIP和PACAP进行了脑内内微注射,以评估它们对食物摄入和神经元激活的影响.
- 在PVN和ARC中的VPAC2mRNA表达用RT-PCR量化.
- 测量了血葡萄糖和自由脂肪酸水平.
- 在ARC和PVN中的细胞激活使用免疫组织化学进行了评估.
主要成果:
- 雌激素治疗减少了OVX大鼠PVN中的VPAC2mRNA表达.
- 在OVX+O和OVX+E组中,PACAP始终降低了食物摄入量和增加了血葡萄糖.
- 在OVX+O大鼠中,VIP诱导了低食 (减少食物摄入),但在OVX+E大鼠中,这种效应被取消了.
- 在两组中,VIP增加了血葡萄糖,在OVX+E大鼠中减少了自由脂肪酸.
- 雌激醇阻断了ARC和PVN中的VIP诱导的神经元激活,而PACAP诱导的激活在OVX+O大鼠的PVN中保持不变.
结论:
- 在OVX大鼠中,雌激素替代选择性地破坏了VIP的阴道效应,但不是PACAP,这表明了不同的信号通路.
- 观察到的干扰与ARC-PVN通路的VIP诱导激活受损有关,由受体表达和下游信号的变化介导.
- 这些发现强调了雌激素在调节涉及能量恒温的下丘脑神经信号传递中的复杂作用.
相关概念视频
Regulation of Food Intake
193
Short-term regulation of food intake primarily involves neural signals from the gastrointestinal (GI) tract, blood nutrient levels, and GI tract hormones. Communication between the gut and brain via vagal nerve fibers plays a significant role in evaluating the contents of the gut. Clinical studies have shown that protein ingestion produces a more prolonged response in these nerve fibers compared to an equivalent amount of glucose. Additionally, the activation of stretch receptors caused by GI...
193
Hormonal Regulation
43.2K
Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.
43.2K
GPCRs Regulate Adenylyl Cylase Activity
5.3K
Some GPCRs transmit signals through adenylyl cyclase (AC), a transmembrane enzyme. AC helps synthesize second messenger cyclic adenosine monophosphate (cAMP). AC catalyzes cyclization reaction and converts ATP to cAMP by releasing a pyrophosphate. The pyrophosphate is further hydrolyzed to phosphate by the enzyme pyrophosphatase, which drives cAMP synthesis to completion. However, cAMP is rapidly degraded to 5′ AMP by the enzymes phosphodiesterase (PDE), preventing overstimulation of...
5.3K
Target Cell Response to Hormones
2.9K
Hormones intricately bind to receptors on the surface or within target cells, initiating a cascade of cellular responses.
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
2.9K
Regulation of Angiogenesis and Blood Supply
2.5K
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl...
2.5K
Regulation of Hormone Secretion
3.2K
Regulation of hormone secretion is a finely tuned orchestration driven by various types of stimuli, encompassing neural, humoral, and hormonal signals. Environmental cues instigate neural stimuli, where action potentials traverse nerve fibers to reach their designated targets. An illustrative scenario is the body's response to stress, wherein the sympathetic nervous system releases epinephrine from the adrenal glands, inducing the well-known 'fight or flight' reaction.
Humoral...
Humoral...
3.2K


