REGULATION OF PITUITARY OPIATE PEPTIDE SECRETION

垂体阿片肽分泌的调节

• 批准号: 3402211
• 负责人: LINDA C SALAND
• 金额: $ 12.41万
• 依托单位: UNIVERSITY OF NEW MEXICO
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-08-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3402211
• 关键词: bioassay; catecholamines; corticotropin releasing factor; dopamine; endorphins; high performance liquid chromatography; hormone regulation /control mechanism; immunocytochemistry; immunoperoxidase; innervation; laboratory rat; ligands; melanocyte stimulating hormone; neural plasticity; neuropeptide receptor; neuropeptides; neurotoxins; neurotransmitter biosynthesis; pituitary gland; proopiomelanocortin; radioimmunoassay; secretion; serotonin

The major goals are to examine the extent of plasticity in regulatory mechanisms for pituitary opiate peptide secretion, both in young rats, and in aging animals. The major hypothesis to be tested is that innervation to pro-opiomelanocortin (POMC) cells of the pituitary intermediate lobe retains the ability to regenerate and regulate peptide secretion after denervation in young individuals, and that during aging, there is modulation of secretion as both nerves and endocrine cells undergo potential degenerative alterations. Questions are: 1. How do POMC endocrine cells respond to denervation and to potential re-innervation over time? Young adult male rats will be treated with a catecholamine neurotoxin, 6-hydroxydopamine (6-OHDA_, which induces neurite degeneration in pituitary. Immunoreactive catecholamine and serotonin innervation will be studied in drug treated and control animals over periods of 8 days, 3 and 6-8 weeks after treatment, to determine the extent of denervation, and of potential re-innervation of endocrine cells. 2. Do POMC cells modify their receptor population to adapt to denervation and potential re- innervation? Pituitary tissue of 6-OHDA treated rats will be studied using autoradiographic techniques with specific radioligands which bind to dopamine-2 (D-2) and serotonin-2 (5-HT-2) receptors, for alterations in receptor patterns which may occur with denervation and re-innervation. 3. How do POMC cells respond to specific regulatory molecules after denervation, and during potential re-innervation? Pituitaries of 6-OHDA treated animals will be incubated in vitro to examine direct effects of inhibitory or stimulatory molecules on peptides secretion. Peptides will be measured by radioimmunoassay (RIA) and tissues studied by immunocytochemical and electron microscopic (EM) techniques. 4. What changes occur in POMC secretory cells and their innervation during normal aging of individual animals? Pituitaries of aging rats (6, 12 and 18 months) will be examined for potential alterations in innervation patterns as well as for modulation of peptide secretion, using immunocytochemistry and RIA for tissue or blood samples. EM techniques will be used to correlate cytology of aging pituitaries with alteration in immunoreactive peptides. To determine if D-2 and 5-HT-2 receptors are altered with age, autoradiographic patterns of ligand binding will be examined. 5. Do aging POMC cells retain the ability to respond to regulatory molecules which inhibit or stimulate secretion? Pituitaries from aging rats will be studied in vitro using neurotransmitters and peptides which have been found to modulate opiate peptide release in young animals. Opiate peptides have significant effects on regulation of pain and on homeostatic mechanisms related to stress. Investigations of plasticity of regulatory mechanisms, in the forms of potential neurite regeneration and modulation of receptor patterns on POMC cells, both in young and aging animals, will be a basis for appropriate pharmacologic manipulation of opiate peptide secretion, in animal models, and in man.

主要目标是检查监管中可塑性的程度 垂体阿片类肽分泌的机制，包括年轻大鼠， 在衰老的动物中。 要检验的主要假设是 垂体中间叶的促蛋白聚糖素（POMC）细胞 保留重新生成和调节肽分泌的能力 年轻人的改造，在衰老期间， 神经和内分泌细胞都会调节分泌 潜在的退行性改变。 问题是：1。pomc如何 内分泌细胞对神经的反应和对潜在的重新发挥作用 时间？ 年轻的成年男性大鼠将接受儿茶酚胺治疗 神经毒素，6-羟基多巴胺（6-OHDA_，诱导神经突变性 在垂体中。 免疫反应性儿茶酚胺和5-羟色胺神经神经将 在8天的时间内在药物治疗和控制动物中进行研究3 在治疗后6-8周，以确定神经支配的程度，并 内分泌细胞的潜在再生。 2。do pomc细胞修改 他们的受体人群适应神经支配和潜在的重新 神经？ 将使用6-OHDA治疗的大鼠的垂体组织进行研究 带有特定放射线的放射自显影技术与 多巴胺-2（D-2）和5-羟色胺2（5-HT-2）受体，用于改变 受体模式可能随着神经支配和重新发作而发生。 3。 POMC细胞如何对特定的调节分子反应 去神经，以及潜在的重新发挥作用吗？ 6-Ohda的垂体 经过治疗的动物将在体外孵育，以检查 肽分泌的抑制或刺激分子。 肽会 可以通过放射免疫测定法（RIA）和通过 免疫细胞化学和电子显微镜（EM）技术。 4。什么 POMC分泌细胞及其在正常情况下的神经发生变化 单个动物老化？ 衰老大鼠的垂体（6、12和18 几个月）将检查神经支配模式的潜在改变 以及使用免疫细胞化学的肽分泌的调节 和RIA用于组织或血液样本。 EM技术将用于 衰老垂体的细胞学与免疫反应性的改变有关 肽。 为了确定D-2和5-HT-2受体是否随着年龄的增长而改变 将检查配体结合的放射自显影模式。 5。衰老 POMC细胞保留对调节分子做出反应的能力 抑制或刺激分泌？ 衰老老鼠的垂体将是 使用已发现的神经递质和肽进行体外研究 调节年轻动物中的鸦片肽释放。 阿片类肽具有 对调节疼痛和稳态机制的显着影响 与压力有关。 调查调节机制的可塑性， 以潜在的神经突再生和受体调节形式 在年轻动物和衰老动物中，POMC细胞上的模式将是一个基础 为了适当对阿片类肽分泌的药理学操纵， 动物模型和人类。