Metabolism of Circulating Hormones by the Fish Gill

除了众所周知的呼吸功能外， 肺在调节多种血浆中起着重要作用 激素，同时也是一种高效的生物过滤器， 其他血液中的分子。 肺的解剖结构 适合进行这些活动，1）整个血液体积 首先通过肺，然后在肺与肺之间分开。 其他器官，和2）肺的广泛毛细血管网络 为等离子体之间的相互作用提供了非常大的表面 分子和代谢活跃的细胞。 以前的工作在此 实验室已经证明鱼鳃具有解剖学特征， 与肺部相同，随后的研究证实， 鳃和哺乳动物的肺一样， 激素如血管紧张素、儿茶酚胺、肾上腺素 和去甲肾上腺素 因此呼吸器官对激素的调节 在脊椎动物进化的早期就发展出来了， 是肺部特有的 拟议的研究将进一步描绘代谢 鳃的各种重要功能， 心血管激素包括血管紧张素、心房利钠素 肽、儿茶酚胺、5-羟色胺和新的血管活性肽 激素T60 K最近在这个实验室被发现。 一个 离体灌流鳃技术已经发展到量化 代谢和确定重要的酶促步骤。 结果 这些研究将与完整的激素代谢进行比较。 鱼，以进一步确定鳃的整体重要性， 激素调节 此外，初步筛选将 根据鳃代谢外来化合物的能力 例如在污染环境中发现的那些。 分离与 培养柱细胞，鳃特有的内皮细胞，将 也可以进行以允许细胞特异性代谢活性。 这项研究的结果对内分泌学家很重要 生理学家对内分泌控制机制感兴趣， 血管内皮的系统发育作为一种 代谢器官 这些结果也很重要，因为它们 为进一步开展能力建设工作提供初步方向， 鳃代谢有毒物质，后者交付给 通过血液或环境来控制鳃。

In addition to its well-known respiratory function the mammalian lung plays an important role in regulating a variety of plasma hormones and also serves as a highly efficient biological filter of other blood-born molecules. The anatomy of the lung is ideally suited to perform these activities, 1) the entire blood volume first passes through the lung before it is divided between the other organs, and 2) the extensive capillary network of the lungs provide a very large surface for interactions between plasma molecules and metabolically active cells. Previous work in this laboratory has shown that the fish gill has anatomical features identical to the lung and subsequent studies have confirmed that the gill, like the mammalian lung is able to metabolize circulating hormones such as angiotensin and the catecholamines, epinephrine and norepinephrine. Thus hormone regulation by respiratory organs developed very early in vertebrate evolution and is not a feature unique to the lung. The proposed research will further delineate the metabolic capabilities of the gill with respect to a variety of important cardiovascular hormones including angiotensin, atrial natriuretic peptides, catecholamines, serotonin and a novel vasoactive peptide hormone T60K that was recently found in this laboratory. An isolated perfused gill technique has been developed to quantify metabolism and identify the important enzymatic steps. Findings form these studies will be compared to hormone metabolism in intact fish to further identify the over-all importance of the gill in hormone regulation. In addition, preliminary screening will be done on the ability of the gill to metabolize foreign compounds such as those found in polluted environments. Isolation and culture of pillar cells, endothelial cells unique to the gill, will also be done to permit cell-specific metabolic activity. Results form this research will be important to endocrinologists and physiologists interested in endocrine control mechanisms and the phylogenetic development of the vascular endothelium as a metabolic organ. These results are also important because they provide the initial direction for further work on the ability of the gill to metabolize toxic substances, the latter delivered to the gill via the blood or the environment.//