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

University Of Wisconsin-Madison, Madison WI

Investigators

Abstract

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.