Control of transport by epithelia

上皮细胞对运输的控制

• 批准号: 3698-2009
• 负责人: Marshall, William
• 金额: $ 1.82万
• 依托单位: St. Francis Xavier University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=568319
• 关键词: Control; transport; epithelia

Teleost fish osmoregulate using active ion and water transport mechanisms of the gills, intestine, kidney and urinary bladder. These epithelial structures contain specialized epithelial transport cells with regulated transport proteins. We study regulation of these transporters in situ in the native epithelium, particularly in mitochondria rich chloride cells of the teleost gill and related osmoregulatory organs as our physiological model system. The ion secretion by hardy euryhaline teleosts such as the killifish Fundulus heteroclitus is rapidly regulated by hormones, neurotransmitters and by the osmotic level of the blood. When fish move from seawater to fresh water, their blood becomes diluted; this transient decrease in osmolality rapidly and reversibly inhibits the salt (NaCl) secretion that is normally present in seawater. In turn, the effect helps the animal retain salt while in fresh water. The effect is a direct cell level regulation by ion transportng cells that sense changes in osmolality. Conversely, blood concentration, such as occurs when the fish enter hypersaline environments stimulates saltsecretion. In addition, these cells also undergo compensation to regulate cell volume. The mechanism involves a series of regulatory proteins, protein kinases and phosphatases that activate or deactivate (respectively) the membrane-bound ion transporters. The research is important to comparative physiology, comparative endocrinology, fisheries and aquaculture. Also, because the anion channel "Cystic Fibrosis Transmembrane conductance Regulator" (CFTR) transports salt in this system, studies of CFTR regulation in fish may be important to discovery of CFTR regulation and important to discovering underlying causes of Cystic Fibrosis.

硬骨鱼通过鳃、肠、肾和膀胱的活性离子和水运输机制来调节渗透压。这些上皮结构含有特殊的上皮运输细胞，具有受调控的运输蛋白。我们研究了这些转运蛋白在天然上皮中的原位调节，特别是在硬骨鱼鳃的富含线粒体的氯化细胞和相关的渗透调节器官中，作为我们的生理模型系统。耐寒的广盐性硬骨鱼，如异地千里鱼，其离子分泌受到荷尔蒙、神经递质和血液渗透水平的快速调节。当鱼从海水移动到淡水时，它们的血液会被稀释；这种渗透性的短暂下降迅速并可逆地抑制了通常存在于海水中的盐分(氯化钠)的分泌。反过来，这种效果有助于动物在淡水中保留盐分。其作用是通过离子转运细胞直接调节细胞水平，从而感知渗透压的变化。相反，血液浓度，如鱼进入高盐环境时发生的情况，会刺激盐分分泌。此外，这些细胞还接受补偿来调节细胞体积。这一机制涉及一系列调节蛋白、蛋白激酶和磷酸酶，它们分别激活或停用膜结合的离子转运体。这项研究对比较生理学、比较内分泌学、渔业和水产养殖业都很重要。此外，由于阴离子通道“囊性纤维化跨膜电导调节器”(CFTR)在该系统中运输盐分，因此对FISH中CFTR调控的研究可能对发现CFTR调控以及发现囊性纤维化的潜在原因具有重要意义。