概括
将人类胰腺生长激素释放因子注入大脑抑制了生长激素的分泌和改变行为. 这表明这个因素在大脑中有一个新的反循环和神经递质作用.
科学领域:
- 神经内分泌学神经内分泌学
- 神经药理学神经药理学
背景情况:
- 增长激素的分泌受 hypothalamic 激素的调节.
- 生长激素释放因子 (GHRF) 是生长激素释放的关键调节者.
研究的目的:
- 为了研究人类胰腺GHRF的中心效应.
- 探索GHRF对自身分泌的超短环负反的潜力.
- 为了检查GHRF在大脑中的神经递质/神经调节功能.
主要方法:
- 以剂量依赖的方式给人胰腺GHRF.
- 测量生长激素分泌和血葡萄糖度.
- 行为和运动活动评估.
- 免疫中和实验使用抗血清对 somatostatin.
主要成果:
- 给予GHRF以剂量依赖的方式抑制生长激素分泌.
- 在GHRF给药后观察到血葡萄糖度升高.
- 显著的行为和运动效应是由GHRF引起的.
- 索马托斯塔丁抗血清并没有逆转GHRF诱导的生长激素抑制.
结论:
- 脑下垂体GHRF可以通过超短环负反机制调节自身的神经分泌.
- 在中枢神经系统内,GHRF具有重要的神经递质和神经调节功能.
- 这些发现扩大了我们对GHRF作用的理解,超出了外围内分泌调节的范围.
相关概念视频
Hormones Regulating Blood Glucose
Insulin is released by beta cells of the pancreas when blood glucose levels are high. It facilitates glucose absorption and utilization in insulin-dependent cells with insulin receptors on their plasma membranes. Insulin promotes glucose uptake by increasing the number of glucose transport proteins in the cell membrane, allowing glucose to enter the cell. As a result, glucose utilization and ATP production are enhanced.
In addition to accelerating glucose uptake and utilization, insulin has...
In addition to accelerating glucose uptake and utilization, insulin has...
Regulation of Food Intake
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...
Glucose Homeostasis: Regulation of Blood Glucose
Carbohydrates consumed through foods are converted into glucose, a crucial energy source for the body. In the prandial state, high blood glucose levels stimulate the secretion of insulin from the pancreas. Insulin inhibits hepatic glucose production and stimulates glucose uptake and metabolism by muscle and adipose tissue. The excess glucose is converted into glycogen and stored in the liver and muscles.
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
During fasting, when blood glucose levels are low, the pancreas secretes glucagon. it...
Glucagon-like Receptor Agonists
Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by the...
Hypoglycemia and Glucagon
Without prolonged fasting, healthy individuals maintain blood glucose levels above 3.5 mM due to a well-adapted neuroendocrine counterregulatory system that effectively prevents acute hypoglycemia, a potentially life-threatening condition. The primary clinical scenarios for hypoglycemia encompass diabetes treatment, inappropriate production of endogenous insulin or insulin-like substances by tumors, and the use of glucose-lowering agents in non-diabetic individuals. Notably, hypoglycemia in the...
Major Hormones and Their Functions
Hormones, the biochemical messengers produced by endocrine glands, are pivotal in regulating bodily functions and maintaining homeostasis. Each hormone's balance is crucial; imbalances can lead to significant physiological disruptions. Major hormones include oxytocin, cortisol, epinephrine, estrogen, testosterone, thyroxine, growth hormone, insulin, and glucagon.
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and lactation.


