HYPERK

超克

• 批准号: 7608060
• 负责人: Jullie W Pan
• 金额: $ 0.36万
• 依托单位: ALBERT EINSTEIN COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-02-15 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7608060
• 关键词: Acute; Blood flow; Brain; Cerebrovascular Circulation; Cerebrum; Computer Retrieval of Information on Scientific Projects Database; Condition; Coupled; Funding; Grant; Human; Hypoglycemia; Hypoglycemic Agents; Image; Institution; Insulin; Measurement; Measures; Metabolism; Oxygen; Oxygen Consumption; Perfusion; Physiological; Rate; Relaxation; Research; Research Personnel; Resources; Rest; Signal Transduction; Source; Testing; Tissues; United States National Institutes of Health; deoxyhemoglobin; interest; volunteer

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This projecte focuses on understanding the physiological effects and fuel needs of the human brain in acute insulin induced hypoglycemia. We have used high field MR perfusion and BOLD imaging in a euglycemic (90-105mg/dl)-hypoglycemic (60mg/dl) clamp in normal human subjeccts to establish the dynamics of cerebral blood flow, oxygen consumption in the resting and task-activated brain. This study has demostrated some very interesting findings under both the euglycemic and hypoglycemic conditions. In particular, in euglycemia we have found that the resting deoxyhemoglobin levels (as evaluated by tissue relaxation measure of R2') is inversely related to the task-activated provoked blood flow. This can be interpreted as: those volunteers who have high efficiency of cerebral oxygen extraction (static deoxyhemoglobin levels are greater if the extraction of oxygen is high) need less of a rise in blood flow to handle the greater demand of oxygen associated with a task This provides a physiological interpretation to the observed variability in R2', flow and potentially BOLD signals (which thus far has been generally assumed to be due to measurement error). This study has also demonstrated that even at a relatively mild hypoglycemic level of 60mg/dl, there is significant rise in cerebral blood flow, from a baseline of 56.8 to 64.5'b18.1ml/100g-min, (p<0.02 paired t-test). While the blood flow increase is seen, there is no effective change in the relaxation rate R2', implying that cerebral metabolism and blood flow remain coupled under these conditions.

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 本项目的重点是了解在急性胰岛素诱导的低血糖症中人类大脑的生理效应和燃料需求。我们在正常人正常血糖（90- 105 mg/dl）-低血糖（60 mg/dl）钳夹中使用高场MR灌注和BOLD成像，以建立静息和任务激活脑的脑血流动力学和氧消耗。这项研究在正常血糖和低血糖条件下都展示了一些非常有趣的发现。特别是，在Euclidean中，我们发现静息脱氧血红蛋白水平（如通过R2 '的组织松弛测量所评估的）与任务激活的激发血流负相关。这可以解释为：那些具有高脑氧提取效率的志愿者（如果氧提取高，则静态脱氧血红蛋白水平更高）需要较少的血流量上升来处理与任务相关的更大的氧需求。这为观察到的R2 ′、流量和潜在BOLD信号的变化（迄今为止，通常认为这是由于测量误差）提供了生理学解释。 这项研究还表明，即使在60 mg/dl的相对轻微的低血糖水平下，脑血流量也有显著增加，从基线56.8增加到64.5 b18.1 ml/100 g-min（p<0.02配对t检验）。虽然观察到血流量增加，但松弛速率R2 '没有有效变化，这意味着脑代谢和血流量在这些条件下保持耦合。