Functional and Evolutionary Physiology of Paracellular Absorption in Flying and Nonflying Mammals

诸如葡萄糖、氨基酸和一些可溶于水的维生素等营养物质主要通过细胞膜(通过特殊的膜转运体)或通过鲜为人知的肠道细胞之间的“旁细胞”途径被小肠吸收。主要研究人员此前曾表明，与非飞行哺乳动物相比，飞行动物(鸟类，可能还有蝙蝠)表现出更强的肠道细胞旁吸收。蝙蝠可能提供一个优越的哺乳动物模型系统，以促进对细胞旁吸收增强机制的理解(S)。该项目将更广泛地测试蝙蝠是否具有相对较高的细胞旁吸收，并将确定蝙蝠增强细胞旁吸收的机制原因。将测量一些蝙蝠物种的细胞旁吸收，以便与大小和饮食相似的非飞行哺乳动物进行比较。将对这两组物种进行详细的比较生理、组织和分子测量。来自该项目的知识可以为理解和控制营养物质、毒素和药物的吸收以促进人类和动物的健康提供重要的见解。研究生、博士后学者以及本科生和高中生，其中一些来自代表性较低的群体，将接受综合生物学培训，强调从全动物到分子的概念和方法。阿根廷和澳大利亚的国际合作得到支持和加强。

Nutrients such as glucose, amino acids and some vitamins that are soluble in water are absorbed by the small intestine mainly across cell membranes (via special membrane transporters) or by a poorly understood "paracellular" pathway between intestinal cells. The principal investigators previously showed that flying animals (birds and perhaps bats) exhibit enhanced intestinal paracellular absorption as compared with nonflying mammals. Bats may provide a superior mammalian model system to advance understanding of the mechanism(s) of enhanced paracellular absorption. This project will test more extensively whether bats have relatively high paracellular absorption and will determine in bats the mechanistic reasons for enhanced paracellular absorption. Paracellular absorption will be measured in a number of bat species for comparison with nonflying mammals of similar size and diet. Detailed comparative physiological, histological and molecular measurements will be made in species of the two groups. Knowledge from this project could provide important insights for understanding and manipulating absorption of nutrients, toxins, and drugs for human and animal health. A graduate student, a postdoctoral scholar, as well as undergraduate and high school students, some from underrepresented groups, will be trained in integrative biology, emphasizing concepts and methods spanning from the whole-animal to the molecular. International collaborations in Argentina and Australia are supported and enhanced.