Assessing the metabolic cost of ion transport using SIET and SPET

生物学中一个尚未得到解答的基本问题是离子在细胞内移动的成本。上皮离子运输对脑脊液形成、营养吸收和盐/水平衡调节等多种过程至关重要，我们对上皮离子运输背后的离子运输机制的理解越来越详细和复杂。然而，尽管上皮离子运输的成本被认为是重要的，但对这一成本的可靠实验估计尚未获得，这在很大程度上是由于在生理相关条件下同时测量离子运动和ATP使用（或其替代品，如O2消耗）的技术挑战。拟议的研究需要最先进的仪器组合，目前在渥太华大学或加拿大任何地方都无法获得：一个结合使用扫描离子电极技术（SIET）和扫描极谱电极技术（SPET）的系统。目前的请求是为购买这种仪器提供资金，这对我们拟议的研究的成功至关重要，也对拟议研究中涉及的HQP的培训至关重要。事实上，使用这种仪器的机会将提供一个在加拿大独一无二的培训机会，如果不是全世界的话。我们提出了SIET和SPET的创新组合，以量化离子运输在鱼类离子细胞、染色质细胞、肠细胞和肾小管中的代谢成本。离子通量将用SIET测量，同时O2通量将用SPET测量

A fundamental question in biology that has yet to be answered concerns the cost of moving ions across a cell. Epithelial ion transport is of critical importance to processes as diverse as cerebrospinal fluid formation, nutrient absorption, and regulation of salt/water balance, and our understanding of the ion transport mechanisms underlying epithelial ion transport is increasingly detailed and complex. However, although the cost of epithelial ion transport is thought to be significant, reliable experimental estimates of this cost have not yet been obtained, in large part owing to the technical challenges of simultaneously measuring ion movements and ATP use (or proxies thereof, such as O2 consumption) under physiologically-relevant conditions. The proposed research requires an assemblage of state-of-the-art instrumentation that currently is not available at the University of Ottawa, or anywhere in Canada for that matter: A system that combines use of the scanning ion electrode technique (SIET) with the scanning polarographic electrode technique (SPET). The current request is for the funding to purchase this instrumentation which is critical to the success of our proposed research and also to the training of HQP involved in the proposed research. Indeed, the opportunity to use this instrumentation will provide a training opportunity that is unique in Canada if not worldwide. We propose an innovative combination of SIET and SPET to quantify the metabolic costs of ion transport in fish ionocytes, chromaffin cells, enterocytes and kidney tubules. Ion fluxes will be measured by SIET while at the same time O2 fluxes will be measured by SPET