Control of transport by epithelia

硬骨鱼利用鳃、肠、肾和膀胱的活性离子和水运输机制来调节呼吸。 这些上皮结构包含具有调节转运蛋白的特化上皮转运细胞。 我们研究这些转运蛋白在原位的天然上皮细胞，特别是在线粒体丰富的硬骨鱼鳃和相关的鳃调节器官作为我们的生理模型系统的氯细胞的调节。 哈代广盐性硬骨鱼如异基底鱼的离子分泌受激素、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;这种渗透压的瞬时降低会迅速而可逆地抑制通常存在于海水中的盐（NaCl）分泌。 反过来，这种效果有助于动物在淡水中保留盐。 该效应是通过感知渗透压变化的离子转运细胞进行的直接细胞水平调节。 相反，血液浓缩，如当鱼进入高盐环境时发生的，刺激盐分泌。 此外，这些细胞还进行补偿以调节细胞体积。 该机制涉及一系列调节蛋白、蛋白激酶和磷酸酶，它们分别激活或灭活膜结合离子转运蛋白。 这一研究对比较生理学、比较内分泌学、渔业和水产养殖学都有重要意义。 此外，因为阴离子通道“囊性纤维化跨膜传导调节器”（CFTR）在该系统中转运盐，所以鱼类中CFTR调节的研究对于发现CFTR调节和发现囊性纤维化的潜在原因可能是重要的。

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.